CN108586624A - A kind of method of air normal pressure plasma jet modification of microcrystalline starch - Google Patents

Abstract

The invention discloses a method for modifying microcrystalline starch by air normal pressure plasma jet. The method is to treat the starch with a certain concentration of hydrochloric acid, gently debranch it, then gelatinize and recrystallize to obtain microcrystalline starch with a high degree of crystallinity, add distilled water to make a certain concentration of starch milk, and directly spray it with air atmospheric pressure plasma jet deal with. Then centrifuge to obtain the precipitate, wash with absolute ethanol three times, vacuum freeze-dry, grind and sieve to obtain the modified microcrystalline starch. This kind of starch has high water-bonding ability and water-absorbing swelling volume, etc., and a certain degree of damage has occurred in the starch structure, which can provide a theoretical basis for further research on starch, and can also be used in the starch industry. It is very good Improve the properties of starch products.

Description

A method for modifying microcrystalline starch by air atmospheric pressure plasma jet

technical field

The invention belongs to the technical field of modified starch production, and in particular relates to a method for modifying microcrystalline starch by air atmospheric pressure plasma jet.

Background technique

Recently, the use of plasma equipment to treat starch, through plasma depolymerization, etching and crosslinking, the research on the modification of starch has been favored by scholars at home and abroad. Because starch itself has many application defects, such as cold water intolerance, gelatinization by heating, high viscosity, low transparency, resistance to enzymes, etc., the modification of starch has always been the mainstream direction in this research field, and physical modification has low pollution. The modified starch can be directly used in the food industry. Plasma treatment is a new non-thermophysical processing method in recent years. It is environmentally friendly and pollution-free, with low energy consumption, high efficiency and simple treatment. Research hotspots in the modification field.

At present, most researchers use dry treatment to complete the modification of starch by plasma, and they are all aimed at the modification of raw starch. They mainly use plasma reaction equipment to directly process dry starch. We found that dry treatment is very easy. To obtain modified starch, the process is simple and the reaction mechanism is clear. However, in actual operation, this method has certain defects, such as uneven treatment, and the amount of samples obtained at one time by dry treatment is very small, and the plasma modified starch method needs to be further improved.

Atmospheric pressure air plasma technology is to use high-voltage current to ionize some atoms or atomic groups in the air under normal pressure conditions to form electrically neutral ionized gas substances composed of positive and negative ions. Through plasma treatment, the substances can undergo various physical and chemical Changes, such as surface etching, internal depolymerization or the formation of a cross-linked layer, etc., so as to achieve food sterilization, enzyme elimination, increase seed germination rate, modified starch and other purposes.

Microcrystalline starch is an acid-modified starch with high crystallinity, good solubility, high transparency, and is not easy to gelatinize. It has a good application prospect in industry and food processing. Plasma treatment is an emerging starch modification method, but there is no research on the modification of microcrystalline starch. Microcrystalline starch is treated with air atmospheric pressure plasma jet technology, and some oxygen-containing polarity is introduced into microcrystalline starch. group, improve the hydrophilicity and cohesiveness of microcrystalline starch, and further improve the practical application performance of microcrystalline starch. The present invention can also provide a new direction of starch modification for future researchers in this direction, and provide more theoretical support for the field of starch research.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a method for modifying microcrystalline starch by air atmospheric pressure plasma jet, which belongs to a new type of physical modification technology. Using this method to process starch can obtain a sufficient amount of samples, and compared to General dry treatment, the modification is more sufficient, using the plasma spray gun jet to directly process a certain concentration of starch milk, which effectively avoids the inhomogeneity of dry treatment, and air atmospheric pressure plasma can also reduce the reaction energy very well. consumption.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A method for modifying microcrystalline starch by air atmospheric pressure plasma jet, comprising the steps of:

(1) Acidly hydrolyze potato starch with hydrochloric acid solution, homogenize once every 30 min, and acidly hydrolyze evenly;

(2) After acidolysis, remove the hydrochloric acid solution by suction filtration, wash the filter cake twice with distilled water, then adjust the pH to 7 with NaOH solution, remove the water by suction filtration, wash with absolute ethanol three times, collect the filter cake and place it in the air at room temperature Dried to obtain acid-thinned potato starch, set aside;

(3) Use deionized water to prepare the acid-lyzed potato starch prepared in step (2) into an acid-lyzed potato starch emulsion with a mass concentration of 10%, heat and gelatinize, boil for 2-3 min, lower the room temperature to 25°C, and centrifuge Take the supernatant, freeze at -18°C for 12 hours, thaw at room temperature until the ice-water mixture is filtered to remove water, wash with absolute ethanol for 3 times, take the filter cake and dry it at room temperature to obtain microcrystalline starch;

(4) Take microcrystalline starch and add distilled water to obtain starch milk, which is treated with air atmospheric pressure plasma jet;

(5) After the air atmospheric pressure plasma jet treatment is completed, the precipitate is collected by centrifugation, and washed 3 times with absolute ethanol;

(6) Vacuum freeze-drying at -50°C for 1.5 h, grinding, and passing through a 100-mesh standard sieve to obtain modified microcrystalline starch.

The concentration of the hydrochloric acid solution in the step (1) is 2.2 mol/L.

The acid hydrolysis temperature in the step (1) is 35°C, and the acid hydrolysis time is 1-7d.

The mass concentration of NaOH solution in the step (2) is 3%.

The speed of centrifugation in the step (3) is 3000rpm, and the centrifugation time is 10min.

The mass concentration of the starch milk in the step (4) is 5-20%.

In the step (4), the treatment time of air normal pressure plasma jet is 1-7 min, the power is 750W, and the height is 14.13mm.

The rotation speed during centrifugation in the step (5) is 3000rpm, and the centrifugation time is 10min.

In the present invention, the raw potato starch is directly added to a 2.2 mol/L hydrochloric acid solution, and the acid hydrolyzed starch is obtained by gentle acid hydrolysis at 35°C for 3 days, and the acid hydrolyzed starch with a mass concentration of 10% is heated and gelatinized, boiled for 2-3 minutes, Freeze at -18°C for 12 hours, thaw, and suction filter to obtain microcrystalline starch with relatively high crystallinity, and then directly treat it with atmospheric air plasma jet, microcrystalline starch emulsion with different time, different concentration and different days of acid hydrolysis, Finally, the precipitate was obtained by centrifugation, vacuum freeze-dried, ground and sieved to obtain plasma jet modified microcrystalline starch.

The modified starch prepared by the invention is fine white powder without impurities and peculiar smell.

The above-mentioned homogenization, suction filtration, vortex, freezing, etc. are all general techniques in the current food processing field.

Compared with the existing technology, it has the following advantages:

(1) the normal pressure air plasma jet that the present invention adopts is a kind of novel non-thermophysical processing technology; (2) the normal pressure air plasma jet that adopts in the present invention handles microcrystalline starch; (3) in the present invention The starch suspension is treated by atmospheric air plasma jet, which is called wet treatment; (4) the present invention uses potato starch as raw material, and through mild acid hydrolysis with hydrochloric acid solution, the acid hydrolyzed starch with a mass concentration of 10% is pasted. and recrystallization to obtain microcrystalline starch with higher crystallinity, then select a suspension of potato microcrystalline starch with a certain concentration, and spray it with air atmospheric pressure plasma jet under certain conditions, the treatment of microcrystalline starch by plasma will form A new type of modified starch, this kind of starch has high water-binding capacity and water-absorbing swelling volume, etc., and the starch structure has been destroyed to a certain extent, which can provide a theoretical basis for further research on starch, and can also be used In the starch industry, it is very good to improve the characteristics of starch products.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that the following examples are only used to illustrate the present invention rather than limit the scope of the present invention, and those skilled in the art can make some non-essential improvements and adjustments based on the content of the above invention.

Example 1

The method for the modified microcrystalline starch of the air atmospheric pressure plasma jet of the present embodiment comprises the following steps:

(1) Acid hydrolyze potato starch with 2.2 mol/L hydrochloric acid solution, 35°C, acid hydrolyze for 3 days, homogenize once every 30 min, and acidly hydrolyze evenly;

(2) After acidolysis, remove the hydrochloric acid solution by suction filtration, wash the filter cake twice with distilled water, adjust the pH to 7 with NaOH solution with a mass concentration of 3% for the third time, remove water by suction filtration, wash with absolute ethanol three times, and collect The filter cake was left to dry at room temperature and set aside;

(3) Use deionized water to prepare the acid-lyzed potato starch prepared in step (2) into an acid-lyzed potato starch emulsion with a mass concentration of 10%, heat and gelatinize, boil for 2-3 minutes, and cool down to 25°C at room temperature. Centrifuge at 3000 rpm for 10 min, take the supernatant at -18°C for 12 h, thaw at room temperature, filter out the water when it reaches the ice-water mixture, wash with absolute ethanol for 3 times, take the filter cake and dry it at room temperature to obtain microcrystalline starch;

(4) Take microcrystalline starch and add distilled water to obtain 5% starch milk, and treat it with air atmospheric pressure plasma jet for 1, 3, 5 and 7 minutes, power 750 W, height 14.13 mm;

(5) After the treatment, centrifuge at 3000 rpm for 10 min, take the precipitate, and wash 3 times with absolute ethanol;

(6) Vacuum freeze-drying at -50°C for 1.5 h, grinding, and passing through a 100-mesh standard sieve to obtain modified microcrystalline starch.

It was determined that after the atmospheric pressure air plasma jet treatment, the structural properties of the sample deteriorated, and the water binding capacity and water swelling volume increased, which means that this method has a destructive effect on the structural properties of microcrystalline starch and improved the microcrystalline starch. The physical properties, and this method, of microcrystalline starch increased with increasing processing time.

Table 1 Effect of different atmospheric pressure plasma jet treatment time on microcrystalline starch

Example 2

The method for the modified microcrystalline starch of the air atmospheric pressure plasma jet of the present embodiment comprises the following steps:

(1) Acid hydrolyze potato starch with 2.2 mol/L hydrochloric acid solution, 35°C, acid hydrolyze for 3 days, homogenize once every 30 min, and acidly hydrolyze evenly;

(2) After acidolysis, remove the hydrochloric acid solution by suction filtration, wash the filter cake twice with distilled water, adjust the pH to 7 with NaOH solution with a mass concentration of 3% for the third time, remove water by suction filtration, wash with absolute ethanol three times, and collect The filter cake was left to dry at room temperature and set aside;

(3) Use deionized water to prepare the acid-lyzed potato starch prepared in step (2) into an acid-lyzed potato starch emulsion with a mass concentration of 10%, heat and gelatinize, boil for 2-3 minutes, and cool down to 25°C at room temperature. Centrifuge at 3000 rpm for 10 min, take the supernatant at -18°C for 12 h, thaw at room temperature, filter out the water when it reaches the ice-water mixture, wash with absolute ethanol for 3 times, take the filter cake and dry it at room temperature to obtain microcrystalline starch;

(4) Take microcrystalline starch and add distilled water to obtain 5, 10, 15 and 20% starch milk, and treat it with air atmospheric pressure plasma jet for 5 minutes, power 750 W, height 14.13 mm;

(5) After the treatment, centrifuge at 3000 rpm for 10 min, take the precipitate, and wash 3 times with absolute ethanol;

(6) Vacuum freeze-drying at -50°C for 1.5 h, grinding, and passing through a 100-mesh standard sieve to obtain modified microcrystalline starch.

It was measured that after atmospheric air plasma jet treatment, the structural properties of the sample deteriorated, and the water binding capacity and water swelling volume increased, but the degree of change had nothing to do with the concentration of microcrystalline starch treated. This method, for microcrystalline starch The degree of influence has almost nothing to do with the concentration change of microcrystalline starch during treatment.

Table 2 Effect of atmospheric pressure plasma jet on different concentrations of microcrystalline starch

Example 3

The method for the modified microcrystalline starch of the air atmospheric pressure plasma jet of the present embodiment comprises the following steps:

(1) Acid hydrolyze potato starch with 2.2 mol/L hydrochloric acid solution, 35°C, acid hydrolyze for 1, 3, 5 and 7 days, homogenize once every 30 min, and acidly hydrolyze evenly;

(2) After acidolysis, remove the hydrochloric acid solution by suction filtration, wash the filter cake twice with distilled water, adjust the pH to 7 with NaOH solution with a mass concentration of 3% for the third time, remove water by suction filtration, wash with absolute ethanol three times, and collect The filter cake was left to dry at room temperature and set aside;

(3) Use deionized water to prepare the acid-lyzed potato starch prepared in step (2) into an acid-lyzed potato starch emulsion with a mass concentration of 10%, and use deionized water to prepare the acid-lyzed potato starch prepared in step (2) Prepare an acid-thinned potato starch emulsion with a mass concentration of 10%, heat gelatinization, boil for 2-3 minutes, cool down to 25°C at room temperature, centrifuge at 3000 rpm for 10 minutes, take the supernatant at -18°C for 12 hours, and thaw at room temperature. When reaching the ice-water mixture, remove the water by suction filtration, wash with absolute ethanol for 3 times, take the filter cake and place it in the air to dry at room temperature to obtain microcrystalline starch;

(4) Take microcrystalline starch and add distilled water to obtain 5% starch milk, and treat it with air atmospheric pressure plasma jet for 5 minutes, power 750 W, height 14.13 mm;

(5) After the treatment, centrifuge at 3000 rpm for 10 min, take the precipitate, and wash 3 times with absolute ethanol;

(6) Vacuum freeze-drying at -50°C for 1.5 h, grinding, and passing through a 100-mesh standard sieve to obtain modified microcrystalline starch.

It was measured that after the atmospheric pressure air plasma jet treatment, the structural properties of the sample deteriorated, and the water binding ability and water swelling volume increased, and the degree of change increased with the increase of the days of microcrystalline starch acid hydrolysis.

Table 3 Effect of atmospheric pressure plasma jet on microcrystalline starch with different acid hydrolysis days

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (8)

1. a kind of method of air normal pressure plasma jet modification of microcrystalline starch, it is characterised in that include the following steps：

（1）With hydrochloric acid solution acid-thinned potato starch, every 30 min homogeneous is primary, uniform acidolysis；

（2）It after acidolysis, filters and removes hydrochloric acid solution, filter cake is washed with distilled water 2 times, then adjusts pH to 7 with NaOH solution, is taken out Water is filtered out, absolute ethyl alcohol washs 3 times, collects filter cake and is placed in and dries to obtain acid-thinned potato starch at room temperature, spare；

（3）With deionized water by step（2）Acid-thinned potato starch obtained is configured to the acid-thinned potato that mass concentration is 10% Starch emulsion, Heat Gelatinization, boil 2-3 min, and room temperature drops to 25 DEG C, centrifuging and taking supernatant, in -18 DEG C of sharp freezings 12 H, water removal is filtered when thaw at RT to mixture of ice and water, and absolute ethyl alcohol washs 3 times, takes filter cake to be placed in and dry at room temperature, obtain crystallite Starch；

（4）It takes Microcrystalline Starch that distilled water is added and obtains starch milk, handled with air normal pressure plasma jet；

（5）Air normal pressure plasma jet after treatment, centrifuging and taking precipitation, absolute ethyl alcohol wash 3 times；

（6）Vacuum freeze drying, -50 DEG C, 1.5 h, grinding crosses 100 mesh standard sieves, obtains modification of microcrystalline starch.

2. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（1）A concentration of 2.2 mol/L of middle hydrochloric acid solution.

3. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（1）The temperature of middle acidolysis is 35 DEG C, and the acidolysis time is 1-7 d.

4. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（2）The mass concentration of middle NaOH solution is 3%.

5. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（3）Rotating speed when middle centrifugation is 3000rpm, centrifugation time 10min.

6. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（4）The mass concentration of starch milk is 5-20%.

7. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（4）The time of middle air atmospheric plasma jet stream processing is 1-7 min, power 750W, is highly 14.13mm.

8. the method for air normal pressure plasma jet modification of microcrystalline starch according to claim 1, it is characterised in that：Institute State step（5）Rotating speed when middle centrifugation is 3000rpm, centrifugation time 10min.