CA2240465A1 - Texture stabilized fresh pasta for cooking directly from the extruder - Google Patents

Abstract

A method for preparing cooked pasta which includes mixing a flour with propyleneglycol alginate and water, extruding the mixture to obtain a pasta shape, cooking, acidifying, packaging and pasteurizing the shaped product without any drying step.
The packaged product is ready to serve for consumption.

Description

CA 0224046~ 1998-06-12 Texture Stabilized Fresh Pasta for Cooking Directly from the Extruder 5 FIELD OF THE ~NVENTION

The invention relates to the preparation of food compositions having good texture and resistance to retrogradation of starch while at the same time reducing the time it takes to process a pasta product. More specifically, the invention relates to a method for 10 improving the texture of pasta or pasta-like products by the incorporation into a dough of an additive, such as propylene glycol ~lgin~te, extruding the product, and then cooking the product without a drying step. From this method, pasta is produced which can be stored, heated and served.

The popularity of pasta as an inexpensive, convenient and nutritious food has rapidly increased. Processes for the commercial manufacture of dry, uncooked pasta are well known. In these processes, water and semolina flour are mixed to provide an 20 alimentary paste. This paste or feedstock is forced through holes of a die attached to an extruder at high pressure and at an elevated temperature, to obtain the desired cross-sectional shape. The extrudate is usually cut to desired lengths. In a conventional pasta extrusion process, the feedstock has a moisture level of about 30 weight percent or more CA 0224046~ 1998-06-12 and is extruded at a temperature of about 120~ F (49~ C). Moisture levels of at least 30 weight percent are needed to mAin~Ain the viscosity of the alimentary paste sufficiently high to prevent excessive pressure within the extruder and to achieve thorough blending.
Temperatures of about 120~ F (49~ C) are utilized to prevent cooking, i.e., gelAtini7.Ation 5 of the starch and/or denaturation of the protein.
Drying is the most time coll~ullling step in the preparation of uncooked pastas. The extrudate generally has a moisture level of at least 28% by weight or generally even more which must be reduced to a value of about 10%-13% to permit storage of the product at ambient conditions. The drying step, or steps may require from about 6-18 hours under 10 carefully controlled conditions such as relative humidity of the air, temperature of the air and rate of air circulation around the pasta. Since the pasta is in its final extruded shape, drying is a very delicate operation. Accelerating the drying process may affect the integrity of the finished product since very rapid drying may cause the pasta to warp or crack.
However, slowing the drying process by allowing freshly made conventional pasta to dry at 15 ambient conditions not only would result in a dry product with unacceptable integrity, but also the pasta might sour or become moldy.
Reducing the time of this drying period or better still eliminAting this conventional drying period without affecting the integrity and quality of the pasta product, would be advantageous when producing pasta, since the energy expended in the drying process would 20 be significantly reduced, thus reducing both the time and the cost of production.
Pastas are commercially available in forms other than dry uncooked pasta, including refrigerated, cooked and partially cooked. Cooked pasta is defined herein to mean pasta wherein substantially all of the starch is gelAtini~ecl and is ready to eat. Uncooked pasta is CA 0224046~ 1998-06-12 defined herein to mean pasta wherein a major portion of the starch is ungel~tini7ed, i.e., greater than about 80% by weight of the total starch content is ungelatinized. The term "uncooked pasta" includes pasta wherein essentially none of the starch is gel~tini7~d.
Starch gelatini7~tion is generally accompanied with protein denaturation. Although protein 5 denaturation is of greater concern, starch gel~tini7~tion can be quantified with greater accuracy and is therefore used herein to deflne cooked and uncooked pasta.
U.S. patent No. 4,965,082 to Chawan et al. (Herein incorporated by reference), discloses a pasta product produced without the conventional drying step. The extrudate is prepared from a feedstock of water, flour and up to 10% ethyl alcohol on a moisture-free 10 basis. When the alcohol-cont~ining feedstock of this invention is extruded from the die, the alimentary paste may be packaged, without a conventional drying step.
The use of ethyl alcohol for the plepalalion of such a product effectively excludes marketing this product to those who abstain from alcohol for religious, health or personal reasons, even though the alcohol may volatilize completely after extrusion/packaging and 15 upon cooking.
U.S. patent application No. 08/408,173, filed March 22, 1995 to Chawan and herein incorporated by reference, discloses a pasta product cont~ining propylene glycol alginate (PGA). The extrudate is prepared by adding 0.01 to about 2.0% to water and mixing the hydrated PGA with ungelatini7ed flour. The extrudate, in the form of a shaped 20 product contains 28 to 30% by weight moisture. The product is then dried by conventional techniques. However, as mentioned above, the limiting step in production of this product is its drying time.
U.S. patent No. 5,599,573 relates to preparing a cooked, acidifled pasta product CA 0224046~ 1998-06-12 optionally cont~ining propylene glycol ~lgin:~t~. This product is prepared by mixing the flour with an acid and other ingredients so that the extruded product includes acid both on the exterior and throughout the body of the product. In addition, this product is produced by the cumbersome process of twice st( ~ming acidified pasta with an intermediate water 5 treatment.
U.S. patent 3,332,786, issued July 25,1967 to Edlin, relates to the stabilization of starch against enzymatic degradation by the addition thereto of propylene glycol alginate.
Edlin teaches the use of propylene glycol alginate to stabilize starch, including wheat starch, against degradation by amylase enzymes in an aqueous acid environment.
10 Improvement of pasta texture is not taught and, in fact, the process of Edlin only produces a paste, not an extrudable pasta.
U.S. patent 2,426,125, issued August 19, 1947 to Steiner describes propylene glycol alginate.

The invention relates to a process for preparing food compositions with good texture. The invention further relates to a method for improving the texture of pasta products and pasta-like products and reducing the processing time for m~mlf~ctllring such products by the incorporation of an additive such as propylene glycol ~l~in~te and by 20 foregoing the conventional drying step. Food products produced by adding propylene glycol alginate to a flour and water dough exhibit dramatic improvement in texture compared to analogous products produced without the addition of propylene glycol alginate, also referred to herein as "PGA".

CA 0224046~ 1998-06-12 In another embodiment, the freshly formed shaped PGA acidifiled pasta is packaged in a vapor barrier pouch, pasteurized and is storable on a grocer's shelf with or without refrigeration. The pasta product produced cooks in less than one-half the time of the conventional dry-pasta, DETAILED DESCRIPTION OF THE INVENTION
The use herein of the term "pasta" shall also include pasta-like food products which may have the appearance of pasta, but which do not meet the accepted standard of identity for a pasta due to, for example, the presence or absence of one or more ingredients. Thus, 10 for example, corn pasta can be prepared by the present invention by incorporating PGA
into corn flour and water. Therefore, by the present invention, "pasta" includes products made with glutinous flour and wheat products such as durum wheat flour, semolina flour and farina flour, as well as buckwheat flour and other flours such as oat flour products, rice flour, corn starch and wheat starch food products con~ining PGA. Legumes can also be 15 used as the source of starch flour. Thus, for example, pea flour, lima bean flour, navy bean flour, soybean flour and the like, or mixtures thereof, can also be used with PGA
according to the present invention. This is a surprising and important feature of the present invention. Dough cannot be extruded from combinations of pea or bean flour and water without PGA. However, by the present invention, extrudable combinations are produced.
20 The food compositions resulting from the use of legume flour, water and the like, possess signirlcantly higher levels of lysine and other amino acids which allow for the production of protein-enriched pasta products. In addition, many consumers cannot tolerate wheat products due to wheat protein sensitivities or allergies. The present invention provides CA 0224046~ 1998-06-12 pasta-like products derived from legumes and other non-wheat flour sources.
In the preparation of pasta and pasta-like products in the present invention, a dough or alimentary paste is prepared by combining an ungel~tini7ed flour, propylene glycol ~lgin~te (PGA) and water. According to the present invention, propylene glycol ~lgin~te is 5 added to the ungelatinized starch and water to form a dough or alimentary paste, preferably before the dough or alimentary paste is formed into a shape and preferably without the addition of an edible acid. Thus, in one embodiment of the present invention, pasta is prepared from ungel~tini7ed semolina or durum wheat flour and water, with the addition of about 0.01 - 2% by weight PGA. A preferred embodiment combines semolina, water, and 10 0.3% by weight PGA. These ingredients and, optionally, whole eggs, egg whites, and other additives, are mixed to form a dough or alimentary paste. If the starch is wheat flour, the dough may also contain added protein, fiber, etc. The paste may contain additives including release agents such as glycerol monostearate, a sulfhydryl reducing agent and added vitamins, e.g. B-vitamins and egg proteins.
Conventionally, sodium diphosphate is added to pasta dough to accelerate the cook time. However, by the present invention, sodium diphosphate is not needed for improved cooking time.
Preferably, the PGA is first hydrated by mixing 6 to 30 grams of PGA in 1000 grams of water. The hydrated PGA is added to the ungel~tini7ed starch or flour as a solid, 20 or preferably as an aqueous solution.
At levels of 1% by weight in the pasta, PGA allows pasta to cook for periods of up to 18 minutes without degradation of flavor or texture. The longer cooking times are desirable for the food service industry because higher yields are produced. Levels of PGA

CA 0224046~ 1998-06-12 of about 1% by weight in the pasta produce less water pickup for comparable cooking time, but higher levels of PGA will guard against overcooking. Such coolcing tolerance is an unexpected and commercially significant advantage of the present invention. A preferred level of PGA in the dough is about 0.3% by weight. The alginate is believed to form a 5 stable complex with starch which reduces solids loss on cooking. Also, the PGA prevents retrogradation of the starch under various conditions of storage. The dough or alimentary paste usually contains at least 28 to 30% by weight moisture prior to extrusion and it has a pH of greater than 5. The pH of the dough can be, for example, from about 6.0 to about 7Ø A preferred pH is about 6.5.
In this application, water or moisture content refers to total moisture, that is, inherent moisture, or moisture naturally present in the flour and other ingredients, as well as added water. The term "water" as used herein includes water in all physical states, i.e., steam, ice or liquid water, or mixtures thereof. The flour, water and any additives used may be mixed in any way conventional in the art, such as by mixing in a vertical cutter 15 mixer (e.g. a Hobart Cutter/Planetary Mixer) for approximately 5 to 10 minutes, at which time the pasta dough is ready for extrusion in any of the conventional pasta shapes.
Shaped pasta is prepared from the paste by extrusion. Extrusion can be performed with any acceptable extruder. The alimentary paste is fed into the extruder wherein it may, optionally, be blended, in the case of a screw-type extruder, or further blended, if the 20 feedstock was premixed before being fed into the extruder, and then forced by internal pressure through the channels or lands of a die face having a plurality of orifices forcing the paste to conform to a desired shape. The orifices of the die face are defined by the openings of through lands or channels in the die head. The shapes of the orifices on the die CA 0224046~ 1998-06-12 face determine the profile of the extruded pasta shape. Such shapes include spaghetti, fettucine, linguine, rotini, elbows, spirals, shells, ziti, vermicelli, fusilli, tortellini, ravioli, manicotti, l~gn~, rote, tortiglioni, or the like.
The alimentary paste passes through the die due to internal pressure genelaled by a 5 rotating screw or screws. Suitable screw speeds range from about 3.5 to 35 revolutions per minute (rpm), and preferably about 20 rpm to 23 rpm. A particularly optimal screw speed is about 25 rpm. In general, screw speeds in excess of about 30 rpm appear to result in a compromised texture and increased starch loss (during cooking) in the pasta product, whereas screw speeds of less than about 3.5 rpm render the extrusion process economically 10 unfeasible.
The screw speed is chosen to result in an extrusion rate, for example, in the range of about 50 grams per minute (g/min) (6.6 Ib/hr) to about 500 g/min (66 Ib/hr) or greater, preferably about 175 g/min (23 Ib/hr), based on a six-orifice die having approximately two inch deep or long lands.
The temperature of the paste may vary within the extruder because of the heat that is generated by friction at different points within the extruder. The temperature of the paste can also vary because it passes through different cooling or heating zones along the length of the extruder barrel. This may be desired where blending is intensified at separate locations in the extruder or components of the paste are added downstream of the feed 20 hopper. However, the highest temperature experienced by the alimentary paste should be preferably below 120~ F (49~ C). The Phrase "standard conditions" as used herein, refers to those experienced in conventional paste extrusion operations where the combination of an extruder barrel temperature of about 120~ F (49~C) or less, and an alimentary paste CA 0224046~ 1998-06-12 moisture content of about 30 weight percent are the norm. The pressures generated under such conditions are generally below 2000 psi in conventional commercial extruders, These pressure values will vary with the equipment utilized.
Where conventional equipment is utilized preferred barrel temperatures fall in the range of about 70~-140 ~F (21 ~C - 60 ~C). Heat generated by friction within the extruder is often more than sufficient to provide the nPcess~ry operating temperatures Alte~ lively, the extruder barrel may be heated by external water jackets or by an electrical resistance heater.
Vacuum pressure may or may not be used. If used, a vacuum of about 15.8 inches Hg(40 cm Hg) to about 28.7 inches Hg(60 cm Hg) preferably about 19.8 inches Hg(40 cm Hg) may be used.
The extruded pasta can then be cooked by conventional methods of stove top boiling in excess water, stove top boiling in exact amount of water (i.e., no-drain cooking, wherein the pasta absorbs all the boiling water), or by microwave cooking.
lS This cooked but undried product is then coated with an acid coating to extend its shelf life and reduce microbial activity during storage. Coating can be accomplished by placing the pasta in a coating drum as disclosed and claimed in U.S. patent No. S,433,964, filed July 9, 1993 by Norman et al., herein incorporated by reference. The interior of the drum, from one end to the other, contains pins. On rotation of the drum, pasta is separated and tumbled by the pins, and the pasta is exposed to an acid spray composition, and preferably, thereafter it is also exposed to an edible oil spray. On discharge from the drum, the pasta can be led to a proportioning or metering machine which can also be a part of a packaging machine. The packaging machine places the pasta in airtight vapor barrier CA 0224046~ 1998-06-12 packages, preferably sealed plastic pouches. The vapor barrier bags used to package the freshly prepared, cooked and coated pasta are preferably polyester film packages or trays of a thickness of 4.5 mils (0.143 mm). The sealed packages or trays are pasteurized in steam or hot water so that the product reaches a temperature of 195~F (91~C). Thus, the size of 5 the package will determine the temperature of the pasteurizing medium and the time the package is exposed to the medium.
Edible acids which can be used in this invention are lactic acid, malic acid, acetic acid, fumaric acid, citric acid, tartaric acid, and phosphoric acids or combinations thereof.
The acid should not impart to the pasta a taste which is not compatible with other 10 components of the product. Preferably, lactic acid is applied to the cooked product, and it is preferable that the acid penetrate throughout the body of the pasta.
The amount of edible acid that is added should provide a cooked pasta product with a pH of less than 5, preferably less than 4.7, and most preferably with the range of 3.5 to 4.3.
The edible oil used to coat the pasta preferably has a melting point below about 104 ~F (40~ C), preferably below about 95~ F (35~ C) to provide the desired function of preventing the fully cooked pasta from sticking and forming a solid mass. Preferably, below about 15% by weight of edible oil is used based on the weight of packaged contents.
Preferred quantities of edible oil generally range from about 1% to about 8% by weight of 20 the total package contents. Suitable edible oils include a vegetable oil, e.g., soybean oil, peanut oil, olive oil, sunflower oil, safflower oil, palm oil, coconut oil and the like. A
particularly preferred separating oil solution is 3.0% oil cont:~ining 0.2762% lecithin. The pasta can also be sprayed with acid and then oil with conventional spraying equipment.

The pasta product, when packaged in a vapor barrier pouch, and pasturized will have good keeping qualities without refrigeration on the grocer's shelf because the coating acid is an antimicrobial agent. This product, which can be distributed as fresh pasta remains soft and is ready to eat. Its major advantages are that it requires no drying, it is 5 ready to eat right from the grocer's sllelf. It cooks in less than one-half the time of the conventional dried pasta as shown in the examples below:
In all of the examples below, PGA was dispersed in water and mixed with semolina to form dough. The dough was extruded through a spaghetti die using the pilot plant MAPA Impianti extruder.

CA 0224046~ 1998-06-12 All three tests had the following parameters.
1. The spaghetti was extruded at 30% dough moisture.

2. The cooked spaghetti was acidif1ed with lactic acid solution.

3. The acidified spaghetti was coated with 3.0% separating oil which contained 0.2762% lecithin.

4. The acidified and oil-coated spaghetti was hot packed in 6-pound pouches, pasteurized and cooled to 40~ F.

5. The finished pouched products were evaluated the next day for Moisture, pll, Surface Free Starch, and Texture.

6. The percent solids loss during cooking was evaluated at various stages: after extrusion, after superheated steam treatment, after 158 ~F (70~ C) 10-hour drying, and six days after drying.

Example 1: The extruded product contained 0.10% PGA on a 10% moisture basis. Five pounds of spaghetti were cooked in 50 pounds of boiling water for 5 minutes.

Example 2: Contained the same amount of PGA as in Example 1. Extruded spaghetti was treated with superheated steam at 250~ F (121~C) for 7.5 minutes. Five pounds of this 20 spaghetti cooked in 50 pounds of boiling water for 6.5 minutes.

Example 3: Contained 0.20% PGA based on a moisture content of 10%. Five pounds of spaghetti were cooked in 50 pounds of boiling water for 5 minutes.

CA 0224046~ 1998-06-12 Comparative Examples 4-6: In addition, uncooked spaghetti of Examples 1 and 3 were dried at 158~F (70~ C) for ten hours to simulate conventional drying prior to cooking to al dente.

5 Cooked spaghetti in each of Examples 1 and 3 and Comparative Examples 4 and 6 was acidified with lactic acid, packed hot in six-pound pouches, pasteurized and cooled to 40 ~F
(4.4~ C). The next day, all samples were evaluated for quality (texture, stickiness, moisture content, pH level, etc.). The results are reported in Table I.

CA 0224046~ 1998-06-12 TABLE I: Test Results of Cooked Enriched Pasta from Extruder Without a Drying Process Example ¦ 1 ¦ 2 ¦ 3 Extruded Pasta, 0.066 - 0.067" Diameter PropyleneGlycolAlginate, % 0.10 0.10 0.20 Moisture Content in Pasta from Extruder, %28.36 ~ 28.56 Moisture Content in Pasta After 7.5-Minute ---- 15.94 ----Superheated Steam Treatment, %
(Dry bulb 250~ F (121~C) and Wet Bulb 165~ F (74~C) Cooking Process Time (Minutes) 5.0 6.5 5.0 Water Temperature, ~F 212 212 212 Pasta to Water Ratio 1:10 1:10 1:10 Finished Acidified Product PercentCoating Oil Added, % 3.0 3.0 3.0 Moisture Content in Pasta After Acidified 65.07 65.68 65.44 and Pouched (%) Surface Free Starch, % 0.90 0.85 0.69 pH 4.29 4.22 4.10 Texture (1 poor - 5 excellent) 4 4 4 CA 0224046~ 1998-06-12 TABLE II: Percent Solid Loss in Pasta Cooking at Various Stages Example ¦ 1 ¦ 2 ¦ 3 Extruded Pasta, 0.066 - 0.067" Diameter Propylene Glycol Alginate, % 0.10 0.10 0.20 Percent Solid Loss* in Cooking (14-Minute 7.61 6.23 7.85 Cook Time) Moisture Content inPasta After 14-Minute 74.26 73.59 73.97 Cook Time, %
After 158~ F (70~ C) 10-Hour Drying Time Example 5 Example 6 Percent Solids Loss in Cooking (20-Minute 7.03 ~7.74 Cook Time) Moisture Content in Pasta After 20-Minute 74.87 ----73.97 Cook Time, %
Six Days After 158~ F (70~ C) 10-Hour Drying Time Percent Solids Loss in Cooking (20-Minute 6.75 ---- 6.96 Cook Time) Moisture Content in Pasta After 20-Minute 74.87 ---- 73.97 Cook Time, %

All the products from the three tests have good to excellent texture and relatively low surface starch (0.69% for Test 3 and 0.90% for Test 1). The average surface free starch on the acidified pasta from production at So-Pak-Co is 0.85%. Our fini~h~-l product 25 specification for surface free starch is 1.5% or less.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or 30 material to the teachings of the invention without departing from the essential scope of the CA 0224046~ 1998-06-12 invention.
Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but the invention will include all embodiments and equivalents falling within the scope of the S amended Claims.

Claims (17)

1. A process for producing a cooked pasta product comprising:
mixing flour, water and propylene glycol alginate in the absence of added acid to form a moldable alimentary paste;
shaping the alimentary paste; and cooking the shaped paste without drying it to produce a pasta product.

2. The process of claim 1 further comprising coating the cooked pasta with an edible acid.

3. The process of claim 1 further comprising coating the cooked pasta with an edible oil.

4. The process of claim 1 further comprising coating the cooked pasta with an edible acid and then coating the cooked pasta with an edible oil.

5. The process of claim 1 wherein the propylene glycol alginate is first hydrated with water prior to adding it to the flour.

6. The process of claim 1 wherein the shaped pasta is cooked in boiling water.

7. The process of claim 1 wherein the shaped pasta is cooked by microwaving it in the exact amount of water.

8. The process of claim 1 wherein coating of the pasta with an edible acid includes the acid penetrating the surface of the pasta product.

9. A process for preparing shaped pieces of alimentary paste which comprises:
preparing a mixed feedstock comprising flour, propylene glycol alginate (PGA) and water to form an alimentary paste having a total moisture content at least about 30% by weight, wherein the amount of PGA is between 0.1 to 1.0% by weight based on a

10% moisture basis;
extruding said mixed feedstock to form shaped pieces;
cooking said pieces and coating said pieces with an edible acid; and packaging and sealing said shaped pieces in a container made of a vapor barrier material.

10. A cooked product, comprising of flour, water, and propylene glycol alginate in amounts of 0.01-2.0% by weight, coated with an edible acid.

11. The cooked acid-coated product of claim 10 further comprising a coating of an edible oil.

12. The cooked product of claim 10 comprising a glutinous flour.

13. The cooked product of claim 10 comprising a flour selected from the group consisting of semolina flour, durum wheat flour, corn flour, buckwheat flour, farina flour, whole wheat flour, oat flour and rice flour.

14. The cooked product of claim 10 comprising a flour selected from the group consisting of pea flour, lima bean flour, navy bean flour and soybean flour.

15. The cooked product of claim 10 wherein the acid is selected from the group consisting of lactic acid, malic acid, acetic acid, fumaric acid, citric acid, tartaric acid, and phosphoric acid and/or combinations thereof.

16. The cooked product of claim 15 wherein the acid is lactic acid.

17. The cooked product of claim 10 wherein the edible oil is selected from the group consisting of soybean oil, peanut oil, olive oil, sunflower oil, safflower oil, palm oil and coconut oil.