BR112019023694B1 - PROCESS TO IMPROVE THE SHELF LIFE OF FRESHLY CUT VEGETABLES - Google Patents

Abstract

The present invention relates to, inter alia, processes for improving the shelf life and flavoring of fresh/freshly cut vegetables, as well as food products produced by these processes. In accordance with the present invention, the processes generally include various novel combinations of steps, such as bleaching, air drying, supercritical fluid processing with and without a processing aid, pressurization, depressurization and packaging. The present invention further relates to methods of preparing edible food products that incorporate processed freshly cut vegetables, as well as food products produced by these methods.

Description

CROSS REFERENCE TO RELATED ORDERS

[0001] This application claims priority benefit of U.S. Provisional Patent Application Serial No. 62/504,889, filed on May 11, 2017, the description of which is incorporated herein by reference in its entirety.

FIELD OF INVENTION

[0002] The present invention relates to, inter alia, processes for improving the shelf life of fresh/freshly cut vegetables.

BACKGROUND OF THE INVENTION

[0003] Fresh vegetables have a short harvest period and tend to spoil quickly if not stored in refrigerated conditions. Some practical methods for extending the shelf life of fresh vegetables have found significant commercial application. These methods include modified atmosphere packaging (MAP)/controlled atmosphere packaging (CAP), air drying, freeze drying, vacuum drying, individually quick freezing (IQF), and canning. With MAP/CAP, shelf life is increased by a few days with refrigeration, from packaging to consumption, because microbial growth depends on storage conditions (Oliveira, et al., 2015). Refrigeration increases the cost of shipping and storing MAP/CAP products.

[0004] Furthermore, when fresh vegetables are peeled and cut, their shelf life is reduced immensely due to the high probability of enhanced enzyme activity and microbial growth. Methods used to extend the shelf life of freshly cut vegetables also include air drying, freeze drying, vacuum drying, IQF, and canning. Dehydration using air is a commercially used practice, but collateral damage to taste, nutritional quality, and structural deformation due to product shrinkage makes the process unattractive. Although freeze drying and vacuum drying provide better quality products, they suffer from the limitations in commercial application of being very expensive (Nijhuis, et al., 1998).

[0005] U.S. Patent No. 4,988,523 describes a sulfite-free anti-tanning coating for fresh peeled potatoes. The patent describes a dipping or spraying process employing a mixture of the commercial preservative SPORIX™ and citric acid. The process can protect the color of fresh peeled potatoes (whole or cut into pieces) for up to 12 days without the use of sulfites and without imparting a sulphite flavor to the potato. However, the process requires the potatoes to be stored in refrigerated conditions (1-4°C).

[0006] Some other techniques that are practiced commercially include canning and IQF. When compared to fresh produce, frozen vegetables that are cooked later have a relatively poor texture. Furthermore, the cost of energy is high for IQF. Likewise, heat treatment during canning deteriorates the texture and nutritional qualities of the product.

[0007] U.S. Patent No. 4,336,273 describes a process for preserving vegetables by exposing them to a spray, vapor or pool of organic compounds, such as aldehydes, amides, esters, hydrocarbons, halogenated hydrocarbons, ketones, etc., for 10-20 minutes at 0° to 75°C. Preservation with this technique requires washing or rinsing the organic compound from the vegetable before thermal processing. The organic compost must be washed carefully and completely. Vegetable aromas are negatively affected by overexposure to organic compounds.

[0008] U.S. Patent No. 5,486,369 describes a combination of bleaching and drying to achieve lower water activity to prevent the growth of microorganisms. The raw potato pieces are first blanched in a heated infusion solution containing one or more sugars and sodium chloride to infuse sugar and sodium chloride into the potato pieces. The potato pieces are dried by subjecting the pieces to heat for a time and temperature sufficient to reduce the water activity of the pieces to below 0.85. These potato pieces can be stored at room temperature and do not require any special packaging. Water activity below 0.85, together with the high concentration of sodium and sugar, produces a final product that does not have the desired characteristics, both in terms of texture and flavor.

[0009] U.S. Published Patent Application No. US-2015/0010691 describes a chemical preservation methodology. It is based on a preservative solution comprising water, sodium chloride, citric acid, ascorbic acid, calcium chloride, sodium acid pyrophosphate, potassium sorbate and a protein-based composition and applying the preservative solution to fresh cut potatoes. These products need to be kept refrigerated throughout their shelf life.

[0010] EP 0811323 describes another chemical preservation technology that uses the application of an aqueous solution, in which a combination of two antioxidant agents participates, specifically potassium metabisulfite and sodium disulfite, as well as a humidifying agent, specifically sorbitol, and a synergistic agent, specifically D.L. ascorbic acid, wherein before immersing the peeled potatoes in said aqueous solution, there is an intermediate humidification phase consisting of a water bath that lasts for a period of approximately 30 minutes. The final product can be stored under refrigeration for 21 days.

[0011] Another method was carried out using SCCO2 with ethanol as a processing aid (co-solvent) for the dehydration of Carrots (Fryer, Norton, bakalis & bridson, 2007). The method describes a batch-type system with continuous CO2 flow mechanism operating with defined process parameters (200 bar (20 MPa); 60°C). During the process, the product is placed without pre-packaging in the high pressure chamber. According to research, the texture of the product is better than air-dried products, but not as good as its freeze-dried counterpart. This process is time-consuming and removes volatile compounds, resulting in loss of aroma and color in the final product. It also states that the SCCO2 drying process is zero order and air drying is a first order process, which is not true in this research.

[0012] Other related research publications show that inactivation of microbial and enzymatic activity can be accomplished by treatment with SCCO2 (Wimmer & Zarevucka, 2010), which is also a batch-type system. US7108832 describes the application of SCCO2 for the sterilization of medically important thermally or hydrolytically sensitive materials, including biodegradable polymers and other medical polymers, tissues for implantation or transplantation, medical equipment, drugs and drug delivery systems. The product is processed in a system with a non-continuous CO2 flow mechanism.

[0013] Similar is U.S. Published Patent Application No. US-2012/0288614 A1, which uses supercritical carbon dioxide to achieve the inactivation of certain microorganisms and enzymes in liquid, semi-solid and solid foods within an apparatus of the type batch with a non-continuous CO2 operation. The operating temperature during the process is 40°C, where the product is packed in a gas permeable (breathable) bag and is placed inside the pressure vessel. The vessel is pressurized to bring the carbon dioxide to the supercritical state and the product is exposed to the supercritical carbon dioxide for various periods of time after which it is slowly depressurized to prevent breakdown of the cellular structure of the product.

[0014] The present invention is aimed at overcoming these and other deficiencies in the art.

SUMMARY OF THE INVENTION

[0015] The present invention relates to, inter alia, processes for improving the shelf life and aroma of fresh/freshly cut vegetables, as well as food products produced by these processes. The present invention further relates to methods of preparing edible food products and food products produced by such methods.

[0016] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables that involves the steps generally described below (herein generally referred to as "Process A"). Firstly, this process involves blanching unprocessed plant material, which includes freshly cut vegetables. Blanching increases the permeability of the cellular structure of freshly cut vegetables. This step produces a blanched vegetable preparation that is enhanced for accelerated moisture removal through a supercritical fluids procedure. Secondly, this process involves subjecting the blanched vegetable preparation to a first supercritical fluid procedure to remove a first percentage of moisture therefrom. The first supercritical fluids procedure is performed with a processing aid, thereby producing an intermediate processed plant product infused with the processing aid. Third, this process involves performing a second supercritical fluids procedure on the intermediate processed plant product to remove a second percentage of moisture therefrom. The second supercritical fluids procedure is performed without the processing aid, thus producing a final processed plant product with improved shelf life compared to unprocessed plant material.

[0017] In another aspect, the present invention also provides a food product that includes the final processed vegetable product prepared by Process A and modalities related thereto.

[0018] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps described below. First, this method involves carrying out Process A or related embodiments thereof to produce the final processed plant product with an improved shelf life compared to unprocessed plant material. Secondly, this method involves processing the final processed vegetable product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

[0019] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables that involves the steps generally described below (herein generally referred to as "Process B"). Firstly, this process involves blanching unprocessed plant material which includes freshly cut vegetables, where blanching increases the permeability of the cellular structure of the freshly cut vegetables. This step produces a blanched vegetable preparation that is enhanced to infuse a processing aid within the cellular structure of the freshly cut vegetables via a supercritical fluids procedure. Secondly, this process involves packaging the blanched vegetable preparation in a sealed gas permeable/breathable container with a defined volume of 0.001% or above one or more processing aids. Third, this process involves subjecting the blanched vegetable preparation within the sealed gas permeable/breathable container to a supercritical fluids procedure at or above supercritical pressures and temperatures, thereby producing a pressurized blanched vegetable preparation contained in the permeable/breathable container. gas breathable. Fourth, this process involves depressurizing the pressurized blanched vegetable preparation rapidly to convert the supercritical fluids into a gaseous phase followed by a slow depressurization phase, thus producing a final vegetable product with an improved shelf life compared to unprocessed plant material. .

[0020] In another aspect, the present invention also provides a food product that includes the final processed vegetable product prepared by Process B and modalities related thereto.

[0021] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps described below. First, this method involves carrying out Process B or related embodiments thereof to produce the final processed plant product with an improved shelf life compared to unprocessed plant material. Secondly, this method involves processing the final processed vegetable product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

[0022] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables that involves the steps generally described below (herein referred to generally as "Process C"). First, this process involves carrying out Process A or related modalities thereof to produce a first final processed plant product. Secondly, this process involves packaging the first final processed plant product in a breathable film bag sealed with a defined volume of one or more co-solvents. Thirdly, this process involves subjecting the first final processed plant product within the sealed breathable film bag to a third supercritical fluids procedure coupled with temperature variations, thereby producing a pressurized first final processed plant product contained in the sealed breathable film bag. . Fourth, this process involves depressurizing the first pressurized final processed plant product rapidly to convert the supercritical fluids into a gaseous phase, followed by a slow depressurization stage, thus producing a complete plant product with an improved shelf life compared to the raw material. unprocessed vegetable.

[0023] In another aspect, the present invention also provides a food product that includes the complete plant product prepared by Process C and modalities related thereto.

[0024] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps described below. First, this method involves performing Process C or related embodiments thereof to produce the complete plant product with an improved shelf life compared to unprocessed plant material. Secondly, this method involves processing the complete plant product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

[0025] The processes of the present invention have the unique ability to reduce water activity and pH within the freshly cut vegetable product. This combination makes the resulting food product shelf-stable without requiring refrigerated or frozen storage conditions. Freshly cut vegetable products can be made from vegetables such as sweet potatoes, yams, artichokes, radishes, carrots, turnips, beet roots, other root vegetables, as well as other non-root vegetables/tubers.

[0026] Some advantages of the processes of the present invention include, for example, processes for making the vegetable product more convenient than currently available fresh products or frozen/canned products. Another advantage is that the processes of the present invention allow the production of healthier food products than currently available fresh or frozen/canned products, reducing the time and temperature required for cooking/frying/baking. Another advantage of the processes of the present invention is the development of alternative shelf life extension methods for freshly cut vegetables to existing methods of dehydration, chemical treatments, freezing and canning.

[0027] In one embodiment of processes for improving the shelf life of freshly cut vegetables, the present invention provides a process involving a combination of blanching treatment, air drying (optional), and supercritical CO2 (SCCO2), with and then, without processing aid (co-solvent), freshly cut vegetables to extend their shelf life at room temperature and even a longer shelf life in refrigerated conditions. Freshly cut and/or peeled vegetables are blanched, partially air-dried (optional) and then treated with SCCO2 which contains the processing aid (co-solvent). Thereafter, SCCO2 treatment can continue without any processing aid (co-solvent) to remove any residual processing aid (co-solvent) from the product.

[0028] These and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] For the purpose of illustrating aspects of the present invention, certain embodiments of the invention are represented in the drawings. However, the invention is not limited to the precise arrangements and instruments of the embodiments depicted in the drawings. In addition, if provided, similar reference numbers contained in the drawings are intended to identify similar or identical elements.

[0030] FIG. 1A is a schematic of a process flow diagram of an embodiment of a process for improving the shelf life of freshly cut vegetables in accordance with the present invention.

[0031] FIG. 1B is a schematic of a process flow diagram of another embodiment of a process for improving the shelf life of freshly cut vegetables in accordance with the present invention.

[0032] FIG. 2 is a graph illustrating moisture content versus drying time for different potato preparation methods.

[0033] FIG. 3A is a graph showing the comparison of the drying and shrinkage rate between an air drying process and a process according to the present invention for potatoes. Arrows indicate which X and Y axes apply. Hybrid process refers to the process of the present invention.

[0034] FIG. 3B is a graph showing the comparison of the drying and shrinkage rate between the air drying process and a process according to the present invention for sweet potatoes. Hybrid process refers to the process of the present invention.

DESCRIPTION OF THE INVENTION

[0035] The present invention provides various processes for improving the shelf life of fresh vegetables. As used herein, "improving shelf life" refers to an improvement in the room temperature shelf life of the vegetable, and a further improvement in its shelf life when stored under refrigerated conditions. One mechanism by which the shelf life of vegetables is improved is due to the removal of moisture from the vegetables, which in turn decreases the water activity (Aw) of the vegetable. Improving shelf life can also include removing moisture and reducing pH and water activity, as well as minimizing shrinkage.

[0036] Vegetables suitable for use in the processes of the present invention can include all vegetables. For example, vegetables suitable for use in the processes of the present invention may include, without limitation, potatoes, sweet potatoes, yams, artichokes, radishes, carrots, turnips, beet roots, other root vegetables, and other non-root vegetables/tubers. .

[0037] As used herein, the term "freshly cut vegetables" refers to vegetables that are cut into portions or pieces before being subjected to any processing (e.g., heating, freezing, canning, and chemical treatments) that would alter its cellular structure in a significant way compared to its cellular structure at the time of harvest. Vegetables can be cut into portions or pieces within about 60 minutes or less before being subjected to blanching as described herein. Vegetables can be cut in any way suitable for the type of vegetable. For example, potatoes can be cut into pieces suitable for standard fries, pies, scalloped potatoes, etc. For vegetables with natural skins (e.g., potatoes), they can be used in the processes of the present invention with or without their skins. For example, when using a potato in the process, the fresh potato can be used with or without the skin.

[0038] As used herein, the term "blanching" generally refers to a process of cooking freshly cut vegetables in water at an elevated temperature for a desired period of time in order to increase permeability within cellular activity and inactivate surface enzymatic activity. In one embodiment, bleaching is conducted at a temperature between about 65-90°C for at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least 30 minutes , at least 35 minutes, and so on, up to a maximum of 120 minutes.

[0039] As used herein, the term "supercritical fluid procedures" generally refers to a process of subjecting a plant material to supercritical fluids in order to infuse/impregnate said product with processing aids to reduce the equilibrium pH of the product, improve the organoleptic properties and/or remove moisture from the product without resulting in shrinkage, thus reducing water activity. Supercritical fluids suitable for use in the process of the present invention may include, without limitation, carbon dioxide, nitrous oxide, ethanol, propane, ethylene, acetone and the like.

[0040] As used herein, a "supercritical pressure" for a substance (e.g., compound, composition, etc.) includes pressures with a value above the critical pressure of that substance.

[0041] As used herein, a "supercritical temperature" for a substance (e.g., compound, composition, etc.) includes temperatures above the critical temperature of that substance.

[0042] As used herein, when a substance (e.g., compound, composition, etc.) is subjected to a pressure and temperature higher than its critical temperature and pressure point, the fluid is considered to be "supercritical ".

[0043] As used herein, the term "processing aid" refers to the co-solvent that is used in a supercritical fluids procedure in order to infuse/impregnate the plant product with one or a combination of several processing aids to improve the organoleptic properties and/or remove moisture from the product without resulting in shrinkage, thus reducing water activity. Suitable processing aids may include, without limitation, co-solvents such as ethanol, distilled vinegar, vinegar, lemon juice, lemon juice concentrate, apple juice, apple juice concentrate, caraway seeds, ginger , garlic, lactic acid, gluconic acid, malic acid, peroxyacetic acid, tartaric acid, acetic acid and its derivatives, sodium bisulfate, gluconodeltalactone (GDL), citric acid, buffers of such acids, oleoresins and the like.

[0044] As used herein, the term "reduce co-solvent" refers to any co-solvent that may be added to plant material during the processes of the present invention in order to lower its pH balance. Suitable reducing co-solvents may include, without limitation, ethanol, distilled water vinegar, vinegar, lemon juice, lemon juice concentrate, apple juice, apple juice concentrate, cumin seed, ginger, garlic, lactic acid , gluconic acid, malic acid, peroxyacetic acid, tartaric acid, acetic acid and its derivatives, sodium bisulfate, gluconodeltalactone (GDL), citric acid, buffers of such acids, oleoresins and the like.

[0045] The processes of the present invention combine several processing steps in a unique way in order to achieve more efficient final results. The bleaching process allows the cell membrane to become more permeable. This increases water removal during air drying as water finds it easier to migrate to the surface. Once the surface moisture has been removed with the help of air drying, the remaining internal moisture needs to be removed with minimal deterioration within the cellular structure of the plant product. Due to the porous cell structure and the surface moisture already removed, the penetration of the modified supercritical fluid (i.e., along with the co-solvent) into the cell structure becomes easier, thus more water present within the inner cell structure can be displaced from the product with minimal shrinkage of the product. Within the process, the supercritical fluid acts as a transport medium that can solubilize the processing aid and transport it to the internal cellular structure which is otherwise not possible efficiently. This solubilized processing aid can now interact with the free water molecules within the cell structure to form bonds and thus together can be carried by the transport medium, the supercritical fluid, without destroying cell walls that could otherwise result in shrinkage. This style of processing allows for uniform removal of moisture from the entire cross-section of the product, thus resulting in lower Aw, water activity of 0.93 or below, which inhibits the growth of various microorganisms of concern to product safety. foods, without adversely affecting the final texture and flavor of the final product.

[0046] Likewise, during the static processing technique, due to the greater permeability within the cellular structure of the product, the supercritical fluid as a transport medium can solubilize the processing aid and transport it to the internal cellular structure to deposit the processing aid there, which is otherwise not efficiently possible. The processing technique is responsible for a rapid depressurization step to change the state of the fluid (transport medium) from the supercritical phase to the gaseous phase that increases the deposition rate. This results in more infusion or impregnation of the processing aid (co-solvent), thus allowing the equilibrium pH to be lowered very quickly. Additionally, further infusion of various essential oils within the product's cellular structure allows for better antimicrobial properties. Uniform deposition of the processing aid generates a lower equilibrium pH of 4.6 or below, which inhibits the growth of various microorganisms of food safety concern, without adversely affecting the final texture and flavor of the final product. This methodology allows the use of very dilute processing aid solutions to achieve equilibrium pH of 4.6 and below, which is otherwise not possible with any other technique. The final product developed using the current technique has a crisper texture, as the processing aid, being acidic, inhibits the breakdown of pectin within the cell wall. And eventually, the final product maintains its texture better and also has a shorter cooking time due to the lower moisture and softer tissue of the final vegetable product. This also results in more than 30% less oil pick-up in the product that is fried in oil.

I. Process A: Improving the shelf life of freshly cut vegetables

[0047] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables, which involves the following steps: (i) blanching unprocessed plant material that includes freshly cut vegetables, wherein blanching increases the permeability of the cellular structure of freshly cut vegetables, thereby producing a blanched vegetable preparation that is enhanced for accelerated moisture removal through a supercritical fluids procedure; (ii) subjecting the blanched vegetable preparation to a first supercritical fluids procedure to remove a first percentage of moisture therefrom, wherein the first supercritical fluids procedure is performed with a processing aid, thereby producing an intermediate processed vegetable product infused with the processing assistant; and (iii) performing a second supercritical fluids procedure on the intermediate processed plant product to remove a second percentage of moisture therefrom, wherein the second supercritical fluids procedure is performed without the processing aid, thereby producing a final processed plant product with improved shelf life compared to unprocessed plant material.

[0048] According to this process, the improved shelf life of the final processed plant product corresponds to a water activity (Aw) below 0.93. In one embodiment, the water activity (Aw) is between about 0.6 and about 0.93.

[0049] According to this process, the percentage of moisture removed from the unprocessed plant material upon completion of the process is between about 1 to 80%.

[0050] According to this process, the first percentage of moisture removed is at least 1 percent.

[0051] According to this process, the second percentage of moisture removed is at least 0.5%.

[0052] In one embodiment, bleaching is conducted at a temperature between about 65-90°C for at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least least 30 minutes, at least 35 minutes, and so on, up to a maximum of 120 minutes.

[0053] In one embodiment of this process, when freshly cut vegetables have an outer skin that can be peeled, the blanching step is carried out with the freshly cut vegetables with and/or without the skin.

[0054] In one embodiment of this process, the first supercritical fluids procedure is performed at or above supercritical pressures and temperatures and at a fluid flow rate at or above 1 liter/minute to provide a residence time of 10 seconds or above of 2 percent or more processing aid of the total mass of freshly cut vegetables for 1 minute or more.

[0055] In one embodiment of this process, the second supercritical fluids procedure is performed at or above supercritical pressures and temperatures and at a fluid flow rate at or above 1 liter/minute to provide a residence time of 10 seconds or more in the absence of processing aid for 1 minute or more.

[0056] In one embodiment of this process, the first supercritical fluids procedure and the second supercritical fluids procedure are performed under continuous flow. For example, when the product is placed in the basket and when that basket is placed in the chamber, then the chamber is closed and the system is equilibrated with the supercritical fluid from the source at 750 psi (5.17 MPa). Once done, the pump is turned on to further pressurize the chamber at or above the critical point so that the fluid is in the supercritical state. During this step, the supercritical fluid enters the chamber along with the processing aid, which is introduced via a separate pump into the chamber. Once the fluid and processing aid come together, the supercritical fluid then solubilizes the processing aid itself and interacts with the plant product to infuse the processing aid (co-solvent) into the cellular structure. The processing aid is introduced at a defined flow rate to obtain 2% or more of the processing aid from the total volume of plant product in the chamber for the total duration of the processing time. When the required pressure and temperature are reached within the chamber, then the supercritical fluid is allowed to flow at a certain rate of 1 liter/minute or above through the chamber along with the processing aid. This style of processing has been termed as continuous flow, wherein the supercritical fluid continuously flows through the chamber at a certain flow rate that results in continuous removal of water/moisture from the product. After the first half of the moisture is removed from the product, the flow of processing aid is then stopped. And the second supercritical fluid procedure is applied over a controlled period of time without the processing aid to help remove the additional half of the moisture along with the extra amount of processing aid (co-solvent) that could potentially adversely affect the profile. flavor of the final product.

[0057] In one embodiment, this process further includes a step of air drying the blanched vegetable preparation before subjecting it to the first supercritical fluids procedure, thus facilitating the removal of moisture from the blanched vegetable preparation during the first blanching procedure. supercritical fluids. In a specific embodiment, the air drying step includes drying at about 50-250°C for 1 minute or above (i.e., up to about 45 minutes).

[0058] In one embodiment, this process further includes the step of reducing the equilibrium pH of the final processed plant product by contacting one or a combination of pH-reducing co-solvents. In a specific embodiment, the equilibrium pH of the final processed plant product is reduced to below 4.6 and as low as about 3.0.

[0059] In another aspect, the present invention also provides a food product that includes the final processed vegetable product prepared by this process.

[0060] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps of: (i) carrying out this process to produce the final processed plant product with an improved shelf life compared to plant material unprocessed; and (ii) process the final processed plant product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

II. Process B: Improving the shelf life of freshly cut vegetables

[0061] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables, which includes the steps of: (i) blanching unprocessed plant material that includes freshly cut vegetables, wherein the blanching increases the permeability of the cellular structure of freshly cut vegetables, thereby producing a blanched vegetable preparation that is enhanced for infusing a processing aid into the cellular structure of freshly cut vegetables through a supercritical fluids procedure; (ii) packaging the blanched vegetable preparation in a sealed gas permeable/breathable container with a defined volume of 0.001% or more of one or more processing aids; (iii) subjecting the blanched vegetable preparation within the sealed gas permeable/breathable container to a supercritical fluids procedure at or above supercritical temperatures and pressures, thereby producing a pressurized blanched vegetable preparation contained in the gas permeable/breathable container; and (iv) depressurizing the pressurized blanched vegetable preparation rapidly to convert the supercritical fluids into a gaseous phase followed by a slow depressurization phase, thereby producing a final vegetable product with an improved shelf life compared to unprocessed plant material.

[0062] In one embodiment, bleaching is conducted at a temperature between about 65-90°C for at least 5 minutes, at least 10 minutes, at least 15 minutes, at least 20 minutes, at least 25 minutes, at least least 30 minutes, at least 35 minutes, and so on, up to a maximum of 120 minutes.

[0063] According to this process, the step of packaging the blanched vegetable preparation in a sealed gas permeable/breathable container is carried out with a defined volume of 0.001% or above of one or more processing aids. As used herein, a "gas permeable/breathable container" refers to any container, bag or pouch that has a breathable film or a porous membrane or a perforated film membrane. Suitable examples of gas permeable/breathable containers for use in this process may include, without limitation, TYVEK® pouches, closure tapes with TYVEK® strips attached, perforated plastic bags/pouches, perforated paper-based bags/pouches. The method of sealing the gas permeable/breathable container may involve the standard methods and techniques for sealing such a container (e.g., heat sealing, manual crimping). The defined volume of one or more processing aids can be between 0.001% to about 30%.

[0064] According to this process, the step of subjecting the blanched vegetable preparation within the sealed gas permeable/breathable container to a supercritical fluids procedure at or above supercritical temperatures and pressures to remove a percentage of moisture therefrom may be performed as noted below. For example, in one embodiment, packaging the peeled vegetable is done in the breathable bag and then adding the processing aid (co-solvent) to the bag is followed by heat sealing the bag. The bag may or may not be turned upside down to allow the processing aid to mix with the plant product. After that, the sealed bags are placed in the perforated basket, which is then placed in the chamber. After the basket is in the chamber, the chamber is then closed and the system is equilibrated with supercritical fluid from the source at 750 psi (5.17 MPa). Once done, then the pump is turned on to further pressurize the chamber at or above the critical point so that the fluid is in the supercritical state. During this step, when the supercritical fluid enters the chamber, it simultaneously enters the bags through the breathable part of the bag and interacts with the processing aid to solubilize it within itself and interact with the plant product to infuse the processing aid. processing (co-solvent) in the cell structure. The processing aid may also be introduced through a separate pump into the chamber at a defined flow rate to obtain 2% or more of the processing aid from the total volume of plant product in the chamber for the total duration of the processing time. When the required pressure and temperature are reached within the chamber and bag, then the product is allowed to stand in the chamber for some time to allow the modified supercritical fluid (i.e. with the processing aid) to infuse into the vegetable product and balance evenly within the vegetable product. After that, the system is quickly depressurized to change the phase of the fluid from the supercritical phase to the gaseous phase, which is then slow depressurized. This rapid depressurization step allows the state of the fluid to change, which results in the separation of the processing aid from the fluid, as the processing aid cannot remain solubilized in the gas phase of the fluid; therefore, this step results in the deposition of the processing aid within the cellular structure of the plant product.

[0065] As used herein, "pressurized" means a pressure above the critical pressure of the fluid.

[0066] According to this process, the step of depressurizing the pressurized blanched vegetable preparation is carried out quickly to convert the supercritical fluids into a gaseous phase followed by a slow depressurization stage, thus producing a final vegetable product with an improved shelf life. compared to unprocessed plant material. As used here, "rapidly" refers to a faster rate of depressurization that results in the sudden drop in fluid pressure below its critical point, thus allowing the fluid to transition from the supercritical phase to the gaseous phase. According to this process, the “slow depressurization stage” is defined as a slower rate of depressurization that does not harm the integrity of the bag or within the vegetable.

[0067] In one embodiment, this process further includes a step of air drying the blanched vegetable preparation before subjecting it to the supercritical fluids procedure, thereby facilitating the removal of moisture from the blanched vegetable preparation during the supercritical fluids procedure. . In a particular embodiment, the air drying step includes drying at about 50-250°C for 1 minute or above (i.e., up to about 45 minutes).

[0068] In one embodiment, this process further includes the step of reducing the equilibrium pH of the final processed plant product by contacting a reducing co-solvent. In a particular embodiment, the equilibrium pH of the final processed plant product is reduced to below 4.6 and as low as about 3.0.

[0069] In one embodiment of this process, the supercritical fluids procedure is carried out under non-flow conditions (0 liters/minute).

[0070] In one embodiment of this process, when freshly cut vegetables have an outer skin that can be peeled, the blanching step is carried out with the freshly cut vegetables with and/or without the skin.

[0071] In another aspect, the present invention also provides a food product that includes the final processed vegetable product prepared by this process.

[0072] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps of: (i) carrying out this process to produce the final processed plant product with an improved shelf life compared to plant material unprocessed; and (ii) process the final processed plant product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

III. Process C: Improving the shelf life of freshly cut vegetables

[0073] In one aspect, the present invention provides a process for improving the shelf life of freshly cut vegetables, which includes the steps of: (i) performing Process A, as described herein, to produce a first final processed vegetable product ; (ii) packaging the first final processed plant product in a breathable film bag sealed with a defined volume of one or more co-solvents; (iii) subjecting the first final processed plant product within the sealed breathable film bag to a third supercritical fluid procedure together with temperature variations, thereby producing a pressurized first final processed plant product contained in the sealed breathable film bag; and (iv) depressurizing the first pressurized final processed plant product rapidly to convert the supercritical fluids into a gaseous phase followed by a slow depressurization phase, thereby producing a complete plant product with an improved shelf life compared to unprocessed plant material.

[0074] As used herein, a "gas permeable/breathable container" refers to any container, bag or pouch that has a breathable film or a porous membrane or a perforated film membrane. Suitable examples of gas permeable/breathable containers for use in this process may include, without limitation, TYVEK® pouches, closure tapes with TYVEK® strips attached, perforated plastic bags/pouches, perforated paper-based bags/pouches, and the like. The method of sealing the gas permeable/breathable container may involve the standard methods and techniques for sealing such a container (e.g., heat sealing). The defined volume of one or more processing aids can be between about 0.001% to about 30%.

[0075] According to this process, the third supercritical fluids procedure (along with temperature variations) may include the plant product processing steps with the steps described for Process A, here, followed by packaging the product into bags/ breathable bags and also introduction of the defined amount of processing aid (co-solvents). The bags would then be heat sealed and placed in the baskets which are then placed in the chamber and the system is pressurized. Once the system reaches the required pressure and temperature within the supercritical state, the product is then left to rest within the chamber for a sufficient time to allow the processing aid to enter the plant product with the help of the processing medium. transport, which is the liquid supercritical fluid and balances evenly within the plant product. After that, the system is quickly depressurized to change the phase of the fluid from supercritical phase to gaseous phase, which is then slow depressurized. This rapid depressurization step allows the state of the fluid to change, which results in the separation of the processing aid from the fluid, as the processing aid cannot remain solubilized in the gas phase of the fluid; therefore, this step results in the deposition of the processing aid within the cellular structure of the plant product. This third supercritical fluid procedure is carried out to produce a first pressurized final processed vegetable product contained in the sealed breathable film bag. As used herein, "pressurized" means a pressure at or above the critical point.

[0076] According to this process, the step of depressurizing the first pressurized final processed plant product is carried out quickly to convert the supercritical fluids into a gaseous phase followed by a slow depressurization stage, thus producing a complete plant product with a shelf life improved compared to unprocessed plant material. As used here, "rapidly" refers to a faster rate of depressurization that results in the sudden drop in fluid pressure below its critical point, thus allowing the fluid to transition from the supercritical phase to the gaseous phase. According to this process, the “slow depressurization stage” is defined as a slower rate of depressurization that does not harm the integrity of the bag or within the vegetable. In another aspect, the present invention also provides a food product that includes the complete plant product prepared by this process.

[0077] In a further aspect, the present invention provides a method for preparing an edible food product that includes the steps of: (i) carrying out this process to produce the final processed plant product with an improved shelf life compared to plant material unprocessed; and (ii) process the complete plant product using culinary techniques that may include, without limitation, boiling, frying, baking, toasting, heating and the like. A food product produced in accordance with this method is also provided by the present invention.

[0078] All numerical ranges are inclusive to narrow ranges; the delineated upper and lower range limits are interchangeable to create other ranges not explicitly delineated.

IV. Additional modalities of a process for improving the shelf life of freshly cut vegetables

[0079] Additional modalities of a process for improving the shelf life of fresh/freshly cut vegetables are described. In one aspect, a new process has been developed, which is a combination of blanching treatment, air drying (optional) and supercritical CO2 (SCCO2), with then without the processing aid (co-solvent) of freshly harvested vegetables. cut to extend their shelf life at room temperature and even a longer shelf life under refrigerated conditions. Processing aids (co-solvents) are polar or non-polar solvents such as ethanol, vinegar, apple juice concentrate, lactic acid, gluconodeltalactone, oleoresins and other materials that are mixed with supercritical CO2.

[0080] An example of the process would be its application to remove moisture from the product to obtain a lower water activity (Aw), including the blanching step of freshly cut and/or peeled vegetables, followed by partial air drying (optional ) and then treatment with SCCO2 containing ethanol. Thereafter, SCCO2 treatment continues without any addition of ethanol to remove any residual ethanol from the product.

[0081] Another example of the process would include the bleaching step, followed by partial air drying (optional) and then SCCO2 treatment with polar acidic processing aid (co-solvent) formulations such as 5% of distilled water vinegar or apple juice concentrate with lemon juice concentrate and garlic to infuse the acid into the cellular structure to achieve a lower equilibrium pH, manipulating the temperature of the carbon dioxide during the process to alter the solubility of CO2 followed by a rapid decrease in pressure to change the state from the supercritical CO2 phase to the gaseous phase.

[0082] Another example of the process would include the bleaching step, followed by partial drying (optional), then SCCO2 treatment with an essential oil such as citral and eugenol to impregnate the processing aid (co-solvent) into the cellular structure of the product by manipulating the temperature of the carbon dioxide during the process to change the solubility of CO2 followed by a rapid decrease in pressure to change the phase state from supercritical CO2 to the gas phase.

[0083] In one aspect, the present invention relates to a process for improving the shelf life of freshly cut vegetables, said process comprising the steps of: (i) blanching freshly cut vegetables (with or without skin) to produce a blanched vegetable preparation; (ii) subjecting the blanched vegetable preparation to a first supercritical CO2 procedure to remove a percentage of moisture (5% or more) therefrom, wherein the first supercritical CO2 procedure is performed with ethanol; and (iii) performing a second supercritical CO2 procedure for preparing blanched vegetables to remove an additional percentage of moisture (5% or above) therefrom, wherein the second supercritical CO2 procedure is performed without ethanol.

[0084] In one embodiment of the process, bleaching is conducted at about 45-90°C for about 5-30 minutes.

[0085] In one embodiment of the process, the first supercritical CO2 procedure is carried out at a pressure of about 150-400 bar (15-40 MPa), a temperature of about 35-130°C, and a flow rate of CO2 of about 1-100 L/minute in a dynamic CO2 operation or a static CO2 operation to provide a residence time of 10 seconds to 20 minutes with 2-8 mol% processing aid (co-solvent ) for about 5-120 minutes.

[0086] In one embodiment of the process, the second supercritical CO2 procedure is carried out at a pressure of about 150-350 bar (15-35 MPa), a temperature of about 35-130°C, and a flow rate of CO2 of about 1-100 L/minute in a dynamic CO2 operation or a static CO2 operation to provide a dwell time of 10 seconds to 20 minutes in the absence of ethanol for about 5-120 minutes.

[0087] In one embodiment of the process, the first supercritical CO2 procedure and the second supercritical CO2 procedure are carried out under continuous or non-continuous flow.

[0088] In one embodiment, the process further comprises air drying the blanched vegetable preparation before subjecting it to the first supercritical CO2 procedure. In a particular embodiment of the process, the air drying step comprises drying at about 50-100°C for about 10-25 minutes.

[0089] In one embodiment, the process comprises infusion/impregnation of soluble compounds in the preparation of blanched vegetables.

[0090] In one embodiment of the process, supercritical CO2 is carried out at a pressure of about 150-350 bar (15-35 MPa), at a temperature of about 35-130°C, and the CO2 flow is static to provide a dwell time of 1-20 minutes.

[0091] In one embodiment of the process, pre-cut vegetables are packaged, wherein the packaging consists of gas permeable/breathable material.

[0092] In one embodiment of the process, the soluble solvents (solid or liquid) are placed in the same packaging as the vegetable or are placed separately in the chamber during the process.

[0093] In one embodiment of the process, the temperature of the carbon dioxide is manipulated to change the solubility of the carbon dioxide during the process and, similarly, the pressure is changed during the process to change the state of the carbon dioxide between the supercritical and gaseous phases.

[0094] The process of the present invention is effective for reducing the equilibrium pH of low-acid vegetable products below 4.6 within the defined run time (30 seconds and above).

[0095] The process of the present invention is effective in reducing enzymatic activity in pre-cut vegetables by more than 95%.

[0096] The process of the present invention can be used to process any vegetable, including, without limitation, vegetables such as sweet potatoes, yams, artichokes, radishes, carrots, turnips, beet roots, other root vegetables, and other root vegetables. not root/tubers.

[0097] The process of the present invention is effective for removing about 30-50% of moisture from freshly cut vegetables.

[0098] In another aspect, the present invention relates to a food product comprising vegetables prepared by a process according to the present invention.

[0099] In another aspect, the present invention relates to a method of preparing an edible food product, said method comprising: (i) carrying out the process according to the present invention, so as to produce a vegetable product with an improved service life with lower Aw (water activity) below 0.93; and (ii) process the plant product using culinary techniques selected from the group consisting of boiling, frying, roasting, toasting, heating and the like. In another aspect, the present invention relates to a food product produced in accordance with this method.

EXAMPLES

[0100] The following examples are intended to illustrate particular embodiments of the present invention, but are in no way intended to limit the scope of the present invention.

EXAMPLE 1 USEFUL LIFE EXTENSION USING SUPERCRITICAL CO2

[0101] An embodiment of a process of the present invention is illustrated in the process flow diagram of FIG. 1A. As shown in FIG. 1A, the process may include the use of supercritical CO2 and the following steps: bleaching, air drying (optional), supercritical CO2 (with a co-solvent), depressurization, supercritical CO2 (without a co-solvent), depressurization and packaging . Alternatively, as shown in FIG. 1A, this modality may include packaging the vegetables after the air drying step and before the supercritical CO2 step (with co-solvent).

[0102] Another embodiment of a process of the present invention is illustrated in the process flow diagram of FIG. 1B. As shown in FIG. 1B, the process may include the use of supercritical CO2 and the following steps: bleaching, air drying (optional), supercritical CO2 (with ethanol as the co-solvent), depressurization, supercritical CO2 (without the ethanol co-solvent), depressurization and vacuum packaging. Alternatively, as shown in FIG. 1B, this embodiment may include addition of volatile aroma after the supercritical (ethanol-free) CO2 step, depressurization, and then vacuum packaging.

[0103] In one embodiment of the process of the present invention, the process may involve the following combination of steps: (i) blanching freshly cut vegetables (with or without peel) at 45-90°C for 5-30 minutes; (ii) optionally, partially air dry the blanched peeled and cut vegetables at 50-100°C for 10-25 minutes; (iii) then process with high pressure SCCO2 containing processing aid (co-solvent) (pressure: 150-350 bar (15-35 MPa); temperature: 35-130°C; CO2 flow rate: 1 -100 L/minute in a dynamic operation to provide a residence time of 10 seconds to 20 minutes; processing aid (co-solvent) flow rate: 2-8 mol% CO2 flow rate) during a period of time; and (iv) optionally, process with SCCO2 without processing aid (co-solvent) (pressure: 150-350 bar (15-35 MPa); temperature: 35-130°C; CO2 flow rate: 1-100 L/minute in a dynamic operation to provide a dwell time of 10 seconds to 20 minutes) over a period of time.

[0104] High pressure during the process increases the solubility of SCCO2 and the higher temperature increases the diffusivity of CO2, which helps increase CO2 penetration (King, Mubarak & Kim, 2005) (Frederick G & Kirkwood, 1930 ) in the product, leading to a more rapid reduction in the water activity of the product, along with a reduction in the pH of the product. This process with a polar processing aid (co-solvent) such as ethanol or 5% distilled water vinegar and other oleoresins also causes an increase in the polarity of SCCO2, thus allowing maximum extraction of cytoplasmic material from any microorganism in the product. and thus achieving a longer useful life. Increasing polarity also increases the rate of water activity reduction, increasing water solubility in supercritical CO2 and causing faster water removal.

[0105] Combining blanching and SCCO2 with processing auxiliary treatments (co-solvent) synergistically increases the ability of these individual treatments to reduce pH and Aw, resulting in freshly cut vegetables in shelf life. Additionally, SCCO2 treatments combined with optional air drying reduce water activity with minimal shrinkage.

[0106] The uniqueness of the process is achieved through the sequence in which the process is carried out. The bleaching process allows the cell membrane to become more porous. This increases water removal during air drying as it is easier to escape to the surface. Due to this, penetration of supercritical carbon dioxide along with processing aid (co-solvent) inside the cell structure becomes easier, therefore, more water present inside the cell structure can be removed from the product with minimum shrinkage of product. Likewise, due to the greater porosity within the cellular structure of the product, further infusion or impregnation of processing aid (co-solvent) such as oleoresins or 5% distilled water vinegar or apple juice concentrate may occur, allowing reducing pH balance quickly. Also more infusion of various essential oils within the cellular structure of the product allows for better antimicrobial properties.

[0107] Although air drying is used as an economical commercial practice for the manufacture of dehydrated products, it results in very low quality shrunken products. On the other hand, the use of SCCO2 results in faster drying with minimal shrinkage. The process, however, is not economically attractive because of high operating costs. As shown in FIG. 2, in FIG. 3A and in FIG. 3B, the drying rate of SCCO2 is not constant throughout the process, as claimed by Brown et al (2010) and follows the same trend as air drying. It can be seen in FIGS. 3A and FIG. 3B, that this air drying rate becomes slower after 20 minutes and therefore it is better to achieve more moisture removal from the product through the SCCO2 process. As for the initial removal of moisture from the product, this can be seen in FIG. 2 that, during the first 20 minutes, the air drying rate for the bleached sample is faster than drying with ethanol containing SCCO2. Drying with SCCO2 after bleaching is initially slower, as SCCO2 becomes saturated more quickly with surface moisture and the rate of water removal by SCCO2 is reduced. Therefore, as finally shown in FIG. 3A and FIG. 3B, with the application of this new process of the invention, it is possible to obtain minimum shrinkage with a maximum drying rate and make the process commercially attractive. With sweet potatoes, a faster rate of drying was observed (shown in FIG. 3B), which makes the process even more attractive on a commercial scale.

[0108] The literature reports prior art methodologies that cannot achieve a reduction in the pH balance of solid food products, such as vegetables and fruits with low acid content within a package. The invention utilizes the combination of blanching the freshly cut vegetable in water, followed by packaging the product in a gas permeable (breathable) bag with the processing aid (co-solvent), in which the low pH formulations are as described. in Table 1. The bleaching process increases porosity within the cellular structure. These packaged products are then treated with supercritical carbon dioxide, where the high pressure allows solubilization of the processing aid (co-solvent) in the SCCO2 and the changes in temperatures during the process allow for faster diffusivity of the solvent and also affect solubility during the process. The residence time in the pressurized chamber allows the infusion of the processing aid (co-solvent) into the cellular structure of the plant through the interaction between the solubilized processing aid (co-solvent) and the product. After this, the pressure is rapidly reduced to bring the CO2 into the gas phase from its supercritical state. This allows separation of the processing aid (co-solvent) from the supercritical CO2 before all the CO2 leaves the system, resulting in a reduction in the pH of the product. Finally, the system is slowly depressurized and the processed plant product is removed from the system.

Unique features of the invention:

[0109] Along with removing moisture from the product during the process, moderately high temperature SCCO2 treatments partially cook the starches, which further decreases the time and temperature required for final preparation/frying/cooking.

[0110] For example, performing combined treatments on fresh potatoes and sweet potatoes results in shelf-stable fries that can be cooked at temperatures below 350°F (176°C) (baking or frying) and for a period of time shorter 10 to 15 minutes when roasted or 2-5 minutes when fried; whereas frozen French fries or sweet potatoes are recommended to be cooked at 400-450°F (204-232 oC) for 20-30 minutes when baked and 5-6 minutes when fried. Unlike frozen French fries which are pre-fried before being frozen, the present invention allows the product to be cooked once over a shorter period of time, resulting in less formation of acrylamide, a potential carcinogen.

[0111] The various processing aids (co-solvents) used in the process include, for example, the following formulations as mentioned in Table 1 below. Table 1: Various processing aids (co-solvents) and their dosage per 100 grams of food product

[0112] The treatment results in a reduction in the pH of the product that is packaged in a gas permeable (breathable) bag, due to the interaction of solubilized lower pH processing aid formulations (co-solvent) with the product. This interaction over time leads to the impregnation of the processing aid (co-solvent) within the cellular structure of the product, which results in the inactivation of the enzyme, since it is known that enzymatic activity depends on the pH of the product. It is also known that lower pH acts as a barrier/control point for the growth of various pathogenic and spoilage microorganisms.

[0113] Various embodiments of the processes of the present invention are provided below.

[0114] In one embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width -0.6 cm; breath - 0.6 cm); (iii) blanching (65-90°C for 5-15 minutes); (iv) air drying (50-100°C for 10-25 minutes); (v) Supercritical CO2 + ethanol (150350 bar (15-35 MPa); 50-90°C; CO2 flow rate 2-100 L/minute to provide a dwell time of 10 seconds to 1 minute; flow rate of ethanol 2-8 moles % CO2 flow rate) at 10-45 minutes {continuous flow}; (vi) depressurization of the container; (vii) Supercritical CO2 (150350 bar (15-35 MPa); 50-90°C; CO2 flow rate 2-100 L/minute to provide a dwell time of 10 seconds to 1 minute) to 10-45 minutes , final moisture removal - 4045% {continuous flow}; (viii) depressurization of the container; and (ix) vacuum packaging.

[0115] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) Cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (65-90°C for 5-15 minutes); (iv) supercritical CO2 + ethanol (150-350 bar (15-35 MPa); 50-90°C; CO2 flow rate 2-100 L/minute to provide a dwell time of 10 seconds to 1 minute; rate of ethanol flow 2-8 moles % CO2 flow rate) at 10-45 minutes {continuous flow}; (v) depressurization of the container; (vi) Supercritical CO2 (150-350 bar (15-35 MPa); 50-90°C; CO2 flow rate 2100 L/minute to provide a dwell time of 10 seconds to 1 minute) to 10-45 minutes , final moisture removal - 40-45% {continuous flow}; (vii) depressurization of the container; and (viii) vacuum packaging.

[0116] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) Cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) air drying (85°C at 25-30 minutes), allowing 18-19% moisture removal; (v) supercritical CO2 + ethanol (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min; ethanol flow rate - 4 mol%) at 1520 minutes {continuous flow}; (vi) depressurization of the container; (vii) supercritical CO2 (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min) at 15-20 minutes, final moisture removal - 40-45% {continuous flow}; (viii) depressurization of the container; and (ix) vacuum packaging.

[0117] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) Supercritical CO2 + ethanol (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min; ethanol flow rate - 4 mol%) at 15-20 minutes {continuous flow} ; (v) depressurization of the container; (vi) supercritical CO2 (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min) at 15-20 minutes, final moisture removal - 40-45% {continuous flow}; (vii) depressurization of the container; and (viii) vacuum packaging.

[0118] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) air drying (85°C at 25-30 minutes) (v) packaging in breathable bags; (vi) supercritical CO2 + apple juice concentrate or 5% distilled water vinegar (300 bar (30 MPa); 100°C at 15-20 minutes {non-continuous flow}; (vii) depressurization of the container.

[0119] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) packaging in breathable bags; (v) supercritical CO2 + apple juice concentrate or 5% distilled water vinegar (300 bar (30 MPa); 100°C at 15-20 minutes {non-continuous flow}; (v) depressurization of the container.

[0120] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) air drying (85°C at 25-30 minutes), allowing 18-19% moisture removal; (v) supercritical CO2 + ethanol (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min; ethanol flow rate - 4 mol%) at 1520 minutes {continuous flow}; (vi) depressurization of the container; (vii) supercritical CO2 (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min) at 15-20 minutes, final moisture removal - 40-45% {continuous flow}; (viii) depressurization of the container; (ix) packaging in breathable bags; (x) supercritical CO2 + apple juice concentrate or 5% distilled water vinegar (300 bar (30 MPa); 100°C at 15-20 minutes {non-continuous flow}; (xi) depressurization of the container.

[0121] In another embodiment of the process of the present invention, the process may involve the following combination of steps: (i) peeling; (ii) cut (length - 0.8 cm; width - 0.6 cm; breath - 0.6 cm); (iii) blanching (85°C at 10 minutes); (iv) Supercritical CO2 + ethanol (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min; ethanol flow rate - 4 mol%) at 15-20 minutes {continuous flow} ; (v) depressurization of the container; (vi) supercritical CO2 (300 bar (30 MPa); 80°C; CO2 flow rate - 4 L/min) at 15-20 minutes, final moisture removal - 40-45% {continuous flow}; (vii) depressurization of the container; (viii) packaging in breathable bags; (ix) supercritical CO2 + apple juice concentrate or 5% distilled water vinegar (300 bar (30 MPa); 100°C at 15-20 minutes {non-continuous flow}; (x) depressurization of the container.

[0122] Process parameters of various embodiments of the process of the present invention are identified in tabular form in Table 2 and Table 3, shown below. Table 2: Various processing parameters of embodiments of the process of the present invention Table 3: Various parameters of embodiments of the method of the present invention

EXAMPLE 3 EXTENSION OF THE SHELF LIFE OF POTATO PRODUCTS Material and methods Potato preparation:

[0123] The potatoes were peeled and cut into standard French fries dimensions: length - 5.90 cm; breathing - 0.8 cm; width - 0.8 cm. The initial moisture content of the potato was calculated by drying the samples at 105°C for 48 hours. The moisture content of the potato was calculated at 78% based on mass loss before and after drying.

Supercritical CO2 drying:

[0124] During the process, CO2 from a cylinder (at 750 psi (5.17 MPa)) was passed to a pump, which compresses the CO2. The compressed CO2 was preheated to the desired temperature with a heating element. After the desired temperature and pressure were reached by the CO2 in the container, the outlet valves were opened to achieve a constant flow rate of CO2 through the product placed in the container. An external high pressure pump was connected to the system to inject ethanol at a desired flow rate. At the end of the experiment, the ethanol flow was stopped and the product was further treated with only supercritical CO2 to remove the remaining processing aid (co-solvent) from the samples in the container. At the end of the process, the container was depressurized. Samples were removed and weighed. When calculating the mass loss: initial mass of the sample - final mass of the sample after processing with supercritical CO2, the moisture loss of the product was calculated and the water activity of the product was measured instrumentally. Measurements for final product dimensions were taken using a Vernier caliper.

Preparation medium:

[0125] PDA: The 15 grams of potato dextrose agar were mixed in 1 liter of deionized water. They were mixed well and then autoclaved at 121°C. The medium was then poured into the Petri dishes and stored in the refrigerator at 4-7°C until used.

[0126] PCA: The 15 grams of agar medium were mixed in 1 liter of deionized water. They were mixed well and then autoclaved at 121°C. The medium was then poured into the Petri dishes and stored in the refrigerator at 4-7°C until used.

[0127] Peptone water: 15 grams of peptone were mixed in 1 liter of deionized water. They were mixed well and then poured into the 10 ml test tubes and the 25 ml screw cap test tubes. These were then autoclaved at 121°C. In each 10 ml test tube, 9 ml of peptone water was poured for serial dilution. And in the 25 ml, 20 ml was poured, which was used to stomach the samples before plating.

Determination of microbial activity:

[0128] The stored samples were opened and placed in the stomach bag and 20 ml of peptone water was added. Then, these samples were placed in the stomach for 3 minutes at 250 rpm. Then, 1 ml of the peptone solution was pipetted out of the bag and added to the 9 ml peptone water test tube. Serial dilution was carried out to 10-6 maximum. Then, 1 ml of the solution was pipetted from the 10-6 serially diluted tube, which was emptied into three PDA and PCA Petri dishes, respectively. It was spread evenly around the entire plate and was stored at 30°C for 48 hours to calculate the total plate count using the formula below:

Measurement of polyphenol oxidase (PPO) activity:

[0129] Enzymatic activity was tested using the method proposed by (Gui, et al., 2005) with modifications. The substrate solution consists of phosphate buffer solution (PBS- 0.05M, pH-6.0) containing 0.05M catechol. 10 grams of potatoes were taken and added to 25 ml of the substrate solution and incubated at 30°C for 50 minutes. PPO activity was determined by measuring the absorbance of the mixture at 420 nm, using a spectrophotometer at room temperature (25°C). PPO activity was determined as the change in absorbance at 420 nm/min and per milliliter of potato sample. The relative PPO activities were obtained with the following formula:

EXAMPLE 4 EXTENSION OF THE SHELF LIFE OF POTATO PRODUCTS Material and methods Potato preparation:

[0130] The potatoes were peeled and cut into standard French fries dimensions: length, 5.90 cm; breathing, 0.8 cm; and width, 0.8 cm.

[0131] Supercritical carbon dioxide process: along with potatoes. The bags were sealed and placed inside a high-pressure treatment vessel. During the process, the CO2 from the cylinder (at 750 psi (5.17 MPa)) was pressurized to the desired pressure by a pump preheated to the desired temperature with a heating element and injected into the treatment vessel. The pressurized container was left static for a predetermined time. Then, the container was quickly depressurized to bring the carbon dioxide into the gaseous phase and slowly emptied.

[0132] pH measurement: Potato samples were removed from the processed bag and 5 g of random sample was collected. The sample was kept on tissue paper to remove any residue from packaging condensation. Then, the samples were cut into small pieces and crushed to form a paste with the addition of deionized water if necessary. The pH probe was dipped into the solutions to measure the pH.

[0133] Reflectance measurement: A colored dye, such as Disperse Blue 79, was placed in 0.1% potato mass, together with the processing aid (co-solvent) in the bag. Once the process was complete, 5 grams of random sample was taken from the processed bag and several cross-sections of the samples were taken. The reflectance of the various cross-sections of the samples was measured using an SP600+ spectrophotometer at a wavelength of 700 nm.

REFERENCES

[0134] Citation of a reference here should not be interpreted as an admission that such reference is prior art to the present invention. All references cited herein are incorporated herein by reference in their entirety. Below is a list of various references relating to the present invention: 1. Bernadette Revel-McInnis Davis, A. G. (2016). U.S. Patent No. 9,271,511 B2. 2. Borisenok, J. G. (1991). U.S. Patent No. 4,988,523A. 3. Brown, Z., Fryer, P., Norton, I., & Bridson, R. (2010). Drying of agar gels using supercritical carbon dioxide. the journal of supercritical fluids, 89-95. 4. Eisenhut, T. W. (2006). U.S. Patent No. 7,108,832B2. 5. Frederick G, K., & Kirkwood, J. G. (1930). The Dielectric Constant of carbon dioxide as a function of temperature and density. Physics review, 754-761. 6. Fryer, Norton, P., Bakalis, I., & bridson, S. &. (2007). Drying of foods using supercritical carbon dioxide- Investigation with carrot. Innovative Food Science & Emerging technologies., 280-289. 7. Gui, F., Wu, J., Chen, F., Liao, X., Hu, X., Zhang, Z., & Wang., Z. (2005). Inactivation of polyphenol oxidase in cloudy apple juice exposed to supercritical carbon dioxide. Journal of Food Chemistry, 1678-1685. 8. King, M., Mubarak, A., & Kim, J. &. (2005). the mutual solubility of water with supercritical and liquid carbon dioxide. Journal of supercritical fluids, 296-302. 9. Lee, C.-H. (1982). U.S. Patent No. 4,336,273 A. 11. Oliveira, M., Abadias, M., Usal, J., Torres, R., Teixido, N., & Vinas, I. (2015). Application of Modified Atmospheric pacakging as a safety approach to fresh cut fruits and vegetables. trends in food science and technology, 1326. 12. Wimmer, Z., & Zarevucka, M. (2010). A Review on the effects of Supercritical Carbon Dioxide on Enzyme Activity. International Journal of Molecular Sciences, 233-253.

[0135] Illustrative embodiments of the processes, methods and products of the present invention are described here. It should be understood, however, that the description herein of specific embodiments is not intended to limit the present invention to the particular forms described, but rather is intended to cover all equivalent and alternative modifications that fall within the spirit and scope of the invention by the attached claims. Thus, although the present invention has been described for the purpose of illustration, it is understood that this detail is for that purpose only and that variations may be made by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the following claims.

Claims (15)

1. Process for improving the shelf life of cut vegetables, characterized by the fact that it comprises the steps of: blanching the cut vegetables; packaging said cut vegetables in a sealed gas permeable/breathable container; processing said cut vegetables within said sealed gas permeable/breathable container and comprising subjecting said cut vegetables within said sealed gas permeable/breathable container to a supercritical fluids procedure, wherein said supercritical fluids procedure of said step processing comprises subjecting said cut vegetables to a supercritical fluid and a processing aid; wherein said supercritical fluid as a transport medium solubilizes the processing aid and transports the processing aid to the internal cellular structure of said cut vegetables to deposit the processing aid therein, and depressurize said cut vegetables within said permeable container /sealed gas breathable container, wherein said depressurization step comprises a first depressurization step and a second depressurization step, within said sealed gas permeable/breathable container, wherein said first step is a rapid depressurization to change the state of the fluid from the supercritical phase to the gaseous phase and the second depressurization step is a slow depressurization, and the first depressurization step allows the state of the fluid to change, which results in the separation of the processing aid from the fluid, therefore processing aid is unable to remain solubilized in the gaseous phase of the fluid; and results in the deposition of the processing aid within the cellular structure of the plant product, wherein said second depressurization step is carried out after said first depressurization step and at a second depressurization rate, and wherein said first depressurization rate is faster than said second depressurization rate. 2. Process, according to claim 1, characterized by the fact that said cut vegetables are free from exposure to heating, freezing, canning, and chemical treatment before carrying out said blanching step. 3. Process according to claim 1 or 2, characterized by the fact that said bleaching step is conducted at a temperature between about 65°C - 90°C for at least 5 minutes. 4. Process according to any one of claims 1 to 3, characterized by the fact that it further comprises cutting vegetables into said cut vegetables, wherein said blanching step is carried out within about 60 minutes after said step cutting. 5. Process according to any one of claims 1 to 4, characterized by the fact that said processing aid used by said supercritical fluids procedure of said processing step is disposed within said gas permeable/breathable container sealed before of subjecting said cut vegetables to said supercritical fluid used by said processing step. 6. Process according to any one of claims 1 to 4, characterized by the fact that said supercritical fluids procedure of said processing step comprises arranging said gas permeable/breathable container sealed within a chamber, and the introducing said supercritical fluid and said processing aid into said chamber. 7. Process according to any one of claims 1 to 6, characterized by the fact that said supercritical fluid used by said supercritical fluids procedure of said processing step is supercritical carbon dioxide. 8. Process according to any one of claims 1 to 7, characterized by the fact that it further comprises: subjecting said cut vegetables to a first supercritical fluids procedure to remove moisture from said cut vegetables, wherein said first supercritical fluid procedure of said moisture removal operation comprises subjecting said cut vegetables to a supercritical fluid and a first processing aid; and subjecting said cut vegetables to a second supercritical fluids procedure to remove moisture from said cut vegetables, wherein said second supercritical fluids procedure of said moisture removal operation is performed after said first supercritical fluids procedure of said moisture removal operation, and wherein said second supercritical fluid procedure of said moisture removal operation comprises subjecting said cut vegetables to a supercritical fluid without said first processing aid. 9. Process according to claim 8, characterized by the fact that it further comprises removing moisture from the surface of said cut vegetables after said blanching step and before said moisture removal operation. 10. Process according to claim 9, characterized by the fact that said step removing surface moisture comprises air drying said cut vegetables. 11. Process according to claim 10, characterized by the fact that said air drying step is conducted at about 50°C - 250°C for at least 1 minute. 12. Process according to any one of claims 8 to 11, characterized by the fact that said first processing aid used by said first supercritical fluids procedure of said moisture removal operation is different from said processing aid used by said supercritical fluid procedure of said processing step. 13. Process according to any one of claims 8 to 12, characterized by the fact that said second supercritical fluids procedure of said moisture removal operation comprises removing said first processing aid from said cut vegetables. 14. Process according to any one of claims 8 to 13, characterized by the fact that said supercritical fluid is the same for each of said first supercritical fluid procedures of said moisture removal operation, said second process of supercritical fluids from said moisture removal operation, and said supercritical fluids procedure from said processing step. 15. Process according to any one of claims 8 to 14, characterized by the fact that said supercritical fluid is supercritical carbon dioxide for each of said first supercritical fluid procedures of said moisture removal operation, said second supercritical fluids procedure of said moisture removal operation, and said supercritical fluids procedure of said processing step.