Introduction of several fruit and vegetable preser

Introduce several fruit and vegetable preservatives

with the in-depth study of fruit and vegetable storage and preservation technology, chemical preservation has also been widely used in production as an effective method to control the ripening, aging and decay of fruits and vegetables. Preservatives can be divided into two categories from the use, namely, film preservatives and chemical preservatives. First of all, let's talk about coating preservatives:

first, waxing preservatives

waxing fruits can increase luster and reduce natural loss. Commonly used waxing materials include mineral wax, paraffin wax, insect wax, carnauba wax, plant wax, etc. The citrus wax developed in Japan can improve the freshness, color, brightness and storage resistance of Citrus after application

II. Natural resin coating preservative

in natural resin, alcohol soluble shellac has good film forming property, fast drying, luster and stability in the air. Shellac, also known as shellac, is treated with 1:7 shellac coating solution (one shellac solution plus 6 parts of water). It can be stored for 10 days and 40 days at room temperature and low temperature respectively. Propolis is a natural biological preservative, which contains resin, gum, wax (30%), essence oil (10%), flavonoids, etc., and has strong antibacterial and bactericidal effects. Ethanol solution of propolis is a good film-forming agent, but attention should be paid to the choice of concentration when using it

III. grease film preservatives

generally, lard, tallow or fats more saturated than lard, such as hydrogenated lard, cottonseed oil, soybean oil, stearic acid monoglyceride, etc. can be selected. China has successfully developed a compound coating preservative, which can be used to treat cherries and store them at room temperature of 20 ℃ -30 ℃ for 10 days, and the good fruit rate is increased by 34%. Some preservatives take lecithin as the main component or lecithin as the main component, and add 2,4-D, calcium salt and polymer to form a Compound Lecithin coating preservative, which is used to store Citrus for 60 days, and the decay rate is below 6%

IV. chitosan derivative coating preservative

chitin and its derivatives are extracted from the shells of shrimp and crab. After deacetylation, other auxiliary agents are added to prepare chitosan derivative coating preservative. The preservative solution can be sprayed on the surface of apples and pears at 10 ℃ -25 ℃ and can be kept fresh for 5 months. In addition, a suitable vegetable preservative was selected from chitosan derivatives, which is suitable for green pepper and tomato. Under suitable conditions, the preservation period can be as long as two months. It is worth noting that chitosan derivatives are ineffective for peaches, and even accelerate deterioration

v. sucrose ester film preservative

sucrose ester is formed by esterification of sucrose and fatty acids. Its chemical structure is composed of highly hydrophilic sucrose and lipophilic fatty acid groups, which has good surface activity. Senber preservative, with sucrose ester, palm oil and plant cellulose as raw materials, is easily soluble in water. After spraying on the surface of fruits and vegetables, it forms a colorless and tasteless film, which has obvious fresh-keeping effect and can effectively prevent decay and deterioration. China has also developed Guoguang brand se-02 film-forming preservative with sucrose ester film-forming agent and special preservative as the main raw materials. The applicable concentration is 1%, which can treat a variety of fruits and vegetables. People have also successfully extracted NPs polysaccharides from semi wild plant Hydrangea flagellata and made them into coating agents, which are widely used in fruits and vegetables. Treating cucumber, tomato, eggplant and other fruits and vegetables with 0.5% NPs multi food aqueous solution can prolong the shelf life. Finally, industry insiders said it would be longer than 10 days

VI. natural mineral film preservative

Germany extracted a natural mineral from the mineral rocks of the rock layer, which is called "after the extrusion of the pipe orifice by biothermon", mainly containing calcium, phosphorus, magnesium, sodium, manganese and other metal salts. Dissolve it in water, make it into a coating agent, and spray it on the surface of perishable fruits and vegetables such as strawberries, bayberry, mushrooms, etc., with a very significant fresh-keeping effect

VII. Protein precipitation solution

Japan uses polymer solutions such as starch and protein plus vegetable oil to make a mixed coating, which is sprayed on fresh apples and oranges. After drying, a very thin film is formed on the surface of fruits and vegetables, extending the storage life of fruits by 3-5 times. Japan also extracted a go from nucleoprotein: gauge distance D: thickness B: width of the middle parallel part; Natural food preservative, the main components are: fish protein extract 35%, glycine 35%, sodium acetate 25%, sodium polyphosphate 5%, suitable for potato preservative

VIII. Domestic coating preservative

Jing 2b-2 preservative is suitable for the fresh storage of apples; Apple and kiwi fruit treated with SM preservative can be stored for 116 days and 14 days at room temperature; Treated with LC preservative, Jinguan and Hongxing can be stored for 180 days at 15 ℃ -18 ℃; Chf-203 coating preservative can be used for the preservation of citrus; Persimmon fresh I preservative is applicable to the coating preservation of persimmons

in recent years, with the improvement of environmental awareness, people have put forward new requirements for food safety. Green food has developed rapidly, and the development of preservatives has gradually developed towards the direction of low toxicity, even non-toxic and edible. People extract more preservatives from natural substances and apply them to the storage and preservation of fruits and vegetables. In China, many Chinese herbal medicines with antiseptic and bacteriostatic effects have been applied. For example, taking the extracts of Chinese herbal medicine clove, rhubarb and galangal as raw materials, adding starch and water to prepare Chinese herbal medicine coating, konjak extract konjak Ganxiang car, small truck tire performance experiment or characteristic measurement can be carried out on this machine. Mannan is also a good Chinese herbal medicine coating preservative. The preparation of Chinese herbal medicine film agent is simple, low cost, less pollution, harmless to human body, and has broad development space. People have also developed garlic extract preservative, phytic acid preservative and other natural preservatives