Preparation and application of the hottest fruit a

2022-08-23
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Preparation and application of fruit and vegetable film preservatives

film preservatives usually make film-forming substances such as wax, natural resin, lipids, gelatin, starch into aqueous solutions or emulsions of appropriate concentration, which are applied to the surface of fruits by dipping, smearing, spraying and other methods, and form a thin transparent film after drying. Its function is to enhance the protective effect of fruit epidermis, appropriately block the opening of epidermis, inhibit respiration and reduce nutrient loss; Inhibit water evaporation and prevent shrinkage and wilting; Inhibit microbial invasion and prevent corruption. Its function is similar to that of single fruit packaging, but compared with single fruit packaging, it has the advantages of low price, suitable for mass processing, increasing the luster of fruit surface and improving the value of goods. If preservatives and physiological activity regulators are added to the coating agent, the fresh-keeping effect can be further improved. Compared with fruits stored in ordinary cold storage, the shelf life of coated fruits can be extended by 1-2 weeks after delivery

I. wax film coating agent

wax is composed of higher fatty acids, esters of higher monohydric alcohols and higher hydrocarbons. It is not easy to deteriorate in the air. Materials science will still further support miniaturization and reduce costs. It has good film-forming property and unique luster of wax, which is suitable for use as film coating agent. Wax commonly used as coating agent includes beeswax, insect wax, carnauba wax, etc

1. Formula 1: ① raw material ratio: 300g beeswax, 100g Arabic gum, 5g sucrose fatty acid ester. ② Mixing method: put the above three kinds of raw materials together and heat them slowly to 40 ℃ to form a paste like mixture. This preservative does not contain toxic substances, so it is necessary to use waterproof materials safely

2. formula 2: ① raw material ratio: 350g beeswax, 3G sucrose fatty acid ester, 4G lecithin, 3G albumin, 60ml coconut oil, 580ml water. ② Formulation and use: soak albumin in warm water, heat and dissolve it, and then add lecithin and sucrose fatty acid ester. Melt the beeswax and add coconut oil. Mix well. The above two liquids are mixed together, stirred, emulsified and dispersed to obtain the required film preservative. This preservative is characterized by moderate viscosity, good film-forming property and convenient use. Put the Yali pear into the emulsion, take it out, dry it, pack it, and store it indoors at 18 ℃. After 30 days (days), the peel is naturally shiny, the fruit color turns slightly yellow, and the hardness is the same as before. The control fruit without preservative softened significantly on the 8th day, and the tail epidermis shrank and faded. In addition, we provided vulnerable parts and spare parts for the new generation of Jinan gold assay equipment and most of the original systems. All raw materials of this preparation are edible and harmless to human body. The film can be removed only by washing with water. This product can also be used for keeping eggs fresh

3. formula 3: ① raw material ratio: 100g beeswax, 20g sodium casein, 10g sucrose fatty acid ester. ② Formulation and use: first dissolve beeswax and sucrose fatty acid esters in ethanol, and then dissolve sodium casein in water. After mixing the two solutions, add water to 1000ml, quickly stir and emulsify the experimental process, and dynamically display the force, displacement, deformation value, loading speed and experimental curve in real time. After dispersing, it is the required preservative. The preservative has appropriate viscosity. It is applied to the surface of apples, pears and other fruits by dipping and coating method, and a protective film can be formed after air drying. Various raw materials of this preparation are non-toxic and safe to use

4. formula 4: ① raw material ratio: 200g paraffin, 3G carnauba wax, 10g sodium alkyl sulfonate. ② Formulation and use: dissolve sodium alkyl sulfonate in an appropriate amount of water, dissolve carnauba wax in an appropriate amount of hot ethanol, heat and melt the paraffin, mix the three liquids together, add water to 1800ml, and quickly stir to emulsify and disperse them, which is the required preservative. The preservative has good film-forming property and luster, and is suitable for coating citrus, apples and other fresh-keeping

5. formula 5: ① raw material ratio: 100g paraffin, 8g ethylene oxide higher fatty alcohol, 6G sorbitan fatty acid ester, 8g sodium alkyl sulfonate, 12ml oleic acid, 1500ml water. ② Mixing and use: melt the paraffin, heat it to about 70 ℃, put other raw materials into the mixture, add warm water and stir evenly, emulsify and disperse to get the film preservative. The preservative is used for the preservation of melons and fruits, which can inhibit respiration and water loss, reduce the loss of nutrients, prevent wilting and delay post ripening. The fresh-keeping agent can also be used for the storage and fresh-keeping of fresh eggs, that is, the fresh eggs are treated by dip coating method, and a protective film is formed after drying, which can prevent the evaporation of water in the eggs and the escape of gas in the air chamber, and prevent the invasion of bacteria, so as to achieve the purpose of fresh-keeping

II. Natural resin film coating agent

in natural resin, alcohol soluble shellac has good film-forming property, fast drying, luster, stable in air, insoluble in water, soluble in ethanol and alkaline solution. Suitable for use as film preservative. The shellac produced in Yuxi, Yunnan, China is of good quality, less impurities, easy to dissolve, and has a natural luster after film formation

1. Formula 1: ① raw material ratio: 100g shellac, 180ml ethanol, 0.6g thiophanate methyl. ② Formulation and use: put shellac into ethanol, stir or shake after slightly warming to accelerate dissolution. After the shellac dissolves and cools down, add methyl tobuzine, shake well, and then get a slightly brownish red translucent coating material. The satisfactory fresh-keeping effect can be achieved by diluting the original solution with 7 times of water, treating apples, oranges, pears, etc. with dip coating method, or treating Yali pears with 10 times of water dilution

2. formula 2: ① raw material ratio: 50g shellac, 20g sodium hydroxide, 80ml ethanol, 8ml ethylene glycol, 1500ml water. ② Formulation and use: add shellac to the mixed solution of ethanol and glycol to dissolve it. Add sodium hydroxide aqueous solution, heat and stir to saponify the completely dissolved shellac. Put citrus, apple, pear and other fruits into the solution, take them out and air dry them to form a transparent thin fresh-keeping film

3. formula 3: ① raw material ratio: shellac 50g, sodium hydroxide 20g, carboamide 3G, polyvinyl alcohol 5g, sodium peroxide 0.02g, ethanol 100ml, water 1500ml. ② Formulation and use: add shellac to ethanol and soak it to dissolve. Add carboamide and polyvinyl alcohol to the aqueous sodium hydroxide solution. After mixing the two liquids, heat and stir constantly to saponify the completely dissolved shellac, and finally add sodium peroxide. Put citrus and other fruits into the above preservative, soak them, remove them and air dry them to form a layer of fresh-keeping film

4. formula 4: ① raw material ratio: 100g shellac, 6G carbendazim, 2,4-D 1.2g, 10g citric acid, appropriate amount of ammonium hydroxide, 2500ml water. ② Formulation and use: dissolve shellac in water with ammonium hydroxide, add 2, 4-D, citric acid and carbendazim dissolved with oleic acid. After all dissolved, adjust the pH value to 8 with ammonium hydroxide to obtain coating preservative. Put apples and others in the solution, take them out and dry them, put them into fruit boxes, and store them in 0 ℃ cold storage. Storage for 6 months, no disease, no decay, bright color, total loss of 0.8%

the fruit treated with the above coating agent has its own callus function, beautiful appearance, anti tissue aging, delaying post ripening, so as to achieve the effect of long-term preservation. It is suitable for the preservation of citrus, orange, apple, pear and other fruits

(to be continued)

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