阅读说明：本技术 一种天然抗氧化剂及其制备方法 (Natural antioxidant and preparation method thereof ) 是由 王雪雅 蓬桂华 李文馨 陆敏 于 2020-07-23 设计创作，主要内容包括：本发明属于食品防腐保鲜技术领域,具体涉及一种天然抗氧化剂及其制备方法；通过从辣椒籽中提取多酚、黄酮、油酸等活性成分制成抗氧化剂,采用水溶性成分与油脂成分相结合的方式制备抗氧化剂,可以从两个方面共同起到抗氧化的作用,且采用两种不同的制备方法,可兼顾多种不同的食品保鲜要求,同时不破坏食物本身的风味,从根本上提高超氧化物歧化酶SOD的活力,清除自由基,同时还能包裹在食物表面,阻隔氧气,减弱紫外线的照射,对食物起到有效抗氧化的作用,有效延长食物的保质期。(The invention belongs to the technical field of food preservation and fresh keeping, and particularly relates to a natural antioxidant and a preparation method thereof; the antioxidant is prepared by extracting active ingredients such as polyphenol, flavone and oleic acid from pepper seeds, and the antioxidant is prepared by combining a water-soluble ingredient and an oil ingredient, so that the antioxidant can play an antioxidant role from two aspects, and two different preparation methods are adopted, so that the requirements of keeping food fresh can be met, the flavor of the food can not be damaged, the activity of superoxide dismutase (SOD) is fundamentally improved, free radicals are eliminated, the SOD can be wrapped on the surface of the food, oxygen is blocked, ultraviolet irradiation is weakened, the antioxidant effect is realized on the food, and the shelf life of the food is effectively prolonged.)

1. A natural antioxidant is characterized by comprising the following components in parts by weight: 20-30 parts of water-soluble active ingredients, 30-45 parts of grease active ingredients and 8-16 parts of surfactants.

2. The natural antioxidant of claim 1, wherein said water soluble active ingredient is prepared by:

a. drying and crushing chilli seeds, dispersing the chilli seeds in distilled water, adding complex enzyme accounting for 4-9% of the weight of the chilli seed powder for enzymolysis, then recovering the enzyme, treating the recovered enzyme by adopting PEF (polyethylene ether-formaldehyde-free) and filtering to obtain filter residue and filtrate;

b. and (b) extracting the filtrate obtained in the step (a) twice by using ethyl acetate as a solvent, combining extract phases, carrying out reduced pressure distillation to remove the solvent, carrying out spray drying, and crushing to obtain the water-soluble active ingredient.

3. The natural antioxidant as claimed in claim 2, wherein the complex enzyme is prepared by mixing protease, cellulase and pectinase in a ratio of 4-8: 10-12: 9-15 by mass ratio.

4. The natural antioxidant as claimed in claim 1, wherein the recovery process comprises adsorbing the enzyme with 10-15% of the substrate of the hybrid cells for 2-3 hours.

5. The natural antioxidant as claimed in claim 1, wherein the oil active ingredient is obtained by subjecting the residue obtained in step a to Soxhlet extraction and reflux with petroleum ether as a solvent.

6. A method for preparing natural antioxidant is characterized in that water soluble active substances are dissolved in citric acid solution and acidified for 1-3h, oil active ingredients and surfactant are added when the temperature is heated to 30-40 ℃, the mixture is stirred to be in a light yellow emulsion state, and the antioxidant powder is obtained after drying and crushing, and the antioxidant powder is prepared into separately packaged capsules.

7. A preparation method of a natural antioxidant is characterized by comprising the following steps:

a. dissolving 20-23 parts by weight of film forming material in 1% glacial acetic acid aqueous solution with equal mass to obtain film forming solution, continuously stirring for 1-2h at room temperature, adding 2-8 parts of oil active ingredient and dispersant, heating, and homogenizing to obtain a basement membrane;

b. and adding the water-soluble active ingredients after the substrate film is cooled, uniformly stirring, pouring into a culture dish, and drying to obtain the film-shaped antioxidant.

8. The method for preparing a natural antioxidant according to claim 7, wherein the film forming material is obtained by soaking chitosan powder in an oxygen-containing inorganic acid with a weight 1.5-2 times of that of the chitosan powder, performing ultrasonic treatment, washing, drying, and then adding alginate with a mass of 6-12% of that of the chitosan powder.

9. The method of claim 7, wherein the dispersing agent includes, but is not limited to, glycerin, mannitol, and polysorbate.

10. The application of a natural antioxidant is characterized in that the capsule-shaped antioxidant powder is directly used in the food processing process or is used after being dissolved by using edible alcohol as a solvent; the film-shaped antioxidant can be used as raw material for food packaging, or can be directly coated on the surface of vegetables and fruits to form edible film.

Technical Field

The invention belongs to the technical field of food preservation and fresh keeping, and particularly relates to a natural antioxidant and a preparation method thereof.

Background

Food antioxidants are food additives that prevent or retard the oxidative deterioration of food, improve the stability of food, and prolong shelf life. The oxidation not only can deteriorate the oil in the food, but also can discolor, discolor and destroy vitamins and the like of the food, thereby reducing the sensory quality and the nutritional value of the food, and even generating harmful substances to cause food poisoning. The most commonly used food antioxidants are phenolics. Five of the antioxidants, BHA (butyl hydroxy anisole), BHT (dibutyl hydroxy toluene), PG (propyl gallate), TBHQ (tert-butyl hydroquinone) and tocopherol, are the antioxidants widely used internationally, can be used independently or used in combination with acid synergists such as citric acid, ascorbic acid and the like, and can meet the requirements of most food products. However, the good effect of keeping the fruits and vegetables fresh cannot be achieved at the same time, and in order to prolong the shelf life of the fruits and vegetables and improve the storage quality of the fruits and vegetables, antioxidants are often used for inhibiting the picked fruits and vegetables from rotting. At present, the antioxidants commonly used in the fruit and vegetable preservation mainly comprise two types of artificially synthesized and natural antioxidants, wherein the artificially synthesized antioxidants comprise methyl jasmonate, propyl gallate and the like, and the natural antioxidants comprise green tea, vitamin C and the like. With the increasing requirements of people on food safety, compared with synthetic antioxidants, the natural antioxidants are more and more widely applied, but the application of the natural antioxidants on the surfaces of fruits and vegetables is easy to cause the defects of low utilization rate, easy air oxidation and the like.

The capsicum contains a large amount of antioxidant substances and also contains abundant vitamin C, carotene and the like, but the capsicum is directly added in the food processing process, the capsaicin in the capsicum can greatly influence the taste of the food, different people have different receptivity to the capsicum, and excessive consumption of the capsicum can cause gastrointestinal mucosa damage and cause diseases such as chronic inflammation. The application of the extracted pepper can not meet the requirements of different food preservation at the same time.

Patent document CN106967506A discloses an edible oil containing natural capsaicin as an antioxidant and the use of the natural capsaicin as an antioxidant, which is prepared by mixing capsaicin: the trans-8-methyl-N-vanillyl-6-nonenamide is directly added into the edible oil to replace a synthetic antioxidant, has no toxic action and good oxidation resistance. However, capsaicin is a cause of a pungent taste felt when eating capsicum, and although it improves the oxidation resistance of the edible oil after being added to the edible oil, it inevitably affects the flavor of the edible oil, and inevitably affects the flavor of dishes when using such an edible oil.

Most of chitosan is modified by cinnamaldehyde in the prior art, the bacteriostatic effect of the traditional method is not good enough, and some films have poor air permeability although the fresh-keeping bacteriostatic effect is good. Although the chitosan film modified by povidone iodine has obvious sterilization effect, the stability of the content of effective iodine is poor, the release speed of the iodine is uncontrollable, and the shelf life of food cannot be effectively prolonged. Patent document No. CN106977622A discloses a method for preparing phenolic acid modified chitosan coating solution for edible fungus preservation, which comprises using chitosan and protocatechuic acid molecules as reaction substrates, synthesizing chitosan-protocatechuic acid graft copolymer with strong antioxidant activity by using 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride mediated crosslinking reaction in ice-water bath environment, and using the graft copolymer for edible fungus coating preservation. The preparation method is prepared aiming at the generation of malondialdehyde in the storage process of pleurotus eryngii, and the shelf life of tropical fruits or fresh fish meat can not be prolonged well for storage and transportation.

Disclosure of Invention

The invention provides an antibacterial and antioxidant edible film for solving the problems.

The method is realized by the following technical scheme:

1. a natural antioxidant comprises the following components in parts by weight: 20-30 parts of water-soluble active ingredients, 30-45 parts of grease active ingredients and 8-16 parts of surfactants.

2. Extracting water-soluble active ingredients:

a. drying and crushing chilli seeds, dispersing the chilli seeds in distilled water, adding complex enzyme accounting for 4-9% of the weight of the chilli seed powder for enzymolysis, then recovering the enzyme, performing PEF treatment for 5-8s at the electric field intensity of 25kV/cm, the pulse width of 13 mu s and the pulse frequency of 725Hz after recovery, and filtering to obtain filter residue and filtrate;

b. and (b) extracting the filtrate obtained in the step a twice by using ethyl acetate as a solvent according to a material-liquid ratio of 1-1.5:2-4, combining extract phases, removing the solvent through reduced pressure distillation, performing spray drying, and crushing to obtain the water-soluble active ingredient.

Furthermore, the compound enzyme is prepared by mixing protease, cellulase and pectinase according to the weight ratio of 4-8: 10-12: 9-15 by mass ratio.

Furthermore, the recovery treatment is to adopt hybrid cells with 10-15% of substrate to adsorb the enzyme for 2-3 h.

3. Extracting active ingredients of the oil: and (b) performing Soxhlet extraction and reflux on the filter residue obtained in the step (a) by using petroleum ether as a solvent.

4. A preparation method of a natural antioxidant comprises the following steps: dissolving water soluble active substance in citric acid solution, acidifying for 1-3 hr, heating to 30-40 deg.C, adding oil active ingredient and surfactant, stirring to give yellowish emulsion, drying, pulverizing to obtain antioxidant powder, and making into separately packaged capsule.

5. A preparation method of a natural antioxidant comprises the following steps:

a. dissolving 20-23 parts by weight of film forming material in 1% glacial acetic acid water solution with the same mass to obtain film forming solution, continuously stirring at room temperature for 1-2h, adding 2-8 parts of oil active ingredient and dispersant, heating, and homogenizing for 5min to obtain a basement membrane;

b. and adding the water-soluble active ingredients after the substrate film is cooled, uniformly stirring, pouring into a culture dish, and drying to obtain the film-shaped antioxidant.

Further, the film forming material is prepared by soaking chitosan powder in oxygen-containing inorganic acid with the weight of 1.5-2 times of that of the chitosan powder for 4-6h, performing ultrasonic treatment with the frequency of 25-30Hz for 10-15min, washing the chitosan powder to be neutral by distilled water, drying the chitosan powder, and adding alginate accounting for 6-12% of the mass of the chitosan powder to obtain modified chitosan serving as a film forming material of a basement membrane.

Further, the dispersant includes, but is not limited to, glycerin, polyvinyl alcohol, and polysorbate.

6. A method for applying a natural antioxidant comprises the following steps: the capsule-shaped antioxidant powder is directly used in food processing process, can be added into liquid food such as pickle water to achieve antiseptic and antioxidant effects, or dissolved in edible alcohol as solvent; the film-shaped antioxidant can be used as raw material for food packaging, or can be directly coated on the surface of vegetables and fruits to form edible film.

In conclusion, the beneficial effects of the invention are as follows: according to the invention, the antioxidant is prepared by extracting active ingredients such as polyphenol, flavone and oleic acid from pepper seeds, the antioxidant is prepared by combining a water-soluble ingredient and an oil ingredient, the antioxidant can play an antioxidant role from two aspects, and two different preparation methods are adopted, so that various food preservation requirements can be considered, the flavor of food is not damaged, the activity of superoxide dismutase (SOD) is fundamentally improved, free radicals are eliminated, the SOD can be wrapped on the surface of the food, oxygen is blocked, ultraviolet irradiation is weakened, the antioxidant effect is effectively realized on the food, and the shelf life of the food is effectively prolonged.

Wherein, the complex enzyme is firstly adopted for enzymolysis, so that the cellulose and cell walls of the pepper seeds can be broken to dissolve out more effective components, the enzyme is recovered by the mixed cells, the enzyme can be recovered to the maximum extent, and the recovered enzyme can be reused. After recovery, PEF is used for treatment, not only can enzyme which is not completely recovered be inactivated, but also a small amount of metal substances in the electrode can be released into the grease, so that partial lipid is subjected to oxidation reaction, the structure of the grease can be changed, the acid value iodine value and the tocopherol content of the grease are improved, the activity of grease components is improved, and the sterilization effect is achieved. Firstly, extracting flavonoids and polyphenol from the chilli seeds by using ethyl acetate, and then extracting oil components from the chilli seeds by using petroleum ether with low polarity, so that the extraction of capsaicin can be reduced, and the purity of the capsaicin is ensured to the maximum extent. Acidification can neutralize capsaicin in capsaicin, and avoid that the food is influenced by capsaicin when the food is preserved by adopting the antioxidant and the flavor of the food is damaged on the contrary because irritant substances of the capsaicin are remained in the antioxidant. And improving the activity of the flavonoid compounds. The capsule is prepared into a capsule shape, the capsule is unscrewed when in use, the storage, carrying and use are convenient, and the contact between the antioxidant and air is reduced due to the independent packaging, so that the pollution is correspondingly reduced, and the activity of the antioxidant is ensured. The antioxidant which is made into a film shape can be coated on the uneven surface of the vegetables and fruits, so that the condition that the antioxidant solution is sprayed unevenly or the antioxidant is lost is avoided. The preparation method comprises the steps of preparing a film forming material by using chitosan and alginate as main raw materials, soaking chitosan powder by using oxygen-containing inorganic acid, and assisting with ultrasonic treatment, wherein a large number of hydroxyl groups are arranged on the surface of chitosan, and when the chitosan powder is treated by using the oxygen-containing inorganic acid, the hydroxyl groups and the inorganic acid undergo an esterification reaction, so that the property of a chitosan derivative can be effectively changed, the antibacterial performance of the chitosan derivative is enhanced, the reaction process can be accelerated by ultrasonic treatment, and a certain activation effect is exerted on chitosan molecules, so that the chitosan molecules are crosslinked more quickly and stably in the film forming process, and the final protective film has stronger toughness and is not easy to break.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.