Use fresh-keeping agent to preserve fresh fruits and vegetables

The coated fresh-keeping agent is usually made of wax (beeswax, paraffin wax, insect wax, etc.), natural resin (the best quality of Yuxi native Yuxi of China), lipids (such as cottonseed oil, etc.), gelatin, starch and other film-forming substances. Made of a suitable concentration of aqueous solution or emulsion. It is applied on the surface of fruits and vegetables by dipping, painting, spraying, etc., and a thin transparent film is formed after air drying to achieve the purpose of inhibiting the respiration of fruits and vegetables. (1) Wax film coating agent such as 100 g beeswax and 10 g sucrose fatty acid ester are dissolved in ethanol, and 20 g casein sodium is dissolved in water, and the two liquids are mixed to a volume of 1000 ml (amount is more The proportion of preparation), rapid stirring, emulsification and dispersion is the required preservative. Dip coating method applied to the surface of tomatoes, eggplants, apples, pears, etc., dried immediately after the formation of a layer of plastic wrap. (2) Natural resin film coating agent The 50 g of shellac is soaked in a mixed solution of 80 ml of ethanol and 80 ml of ethylene glycol to dissolve it. Add 1500 ml of sodium hydroxide aqueous solution (formulated from 20 g of NaOH), heat and stir, and saponify the dissolved shellac (the amount is adjusted to match the above ratio). Apples, oranges, pears, and other fruits are soaked in this solution. After being taken out, they are air-dried to form a thin transparent plastic wrap. (3) Grease film coating agent Agar is first soaked in 1000 ml of warm water and heated to open after swelling. Then, 2 g of casein sodium, 2.5 g of fatty monoglyceride and 400 g of soybean oil were added, and the mixture was stirred at a high speed to obtain an emulsion (the amount was adjusted according to the above ratio). The fresh food to be immersed in the emulsion, taken out and stored after air drying, significantly longer preservation period. For example, the broad bean pods were treated with the above emulsion and stored at room temperature for half a month and remained green. Untreated broad bean pods appear dark on the surface after 3 days. This preservative is suitable for storage and transportation of fruits and fruits and vegetables. (4) Other film coating agents