Using soybean wrapping paper to package food can not only maintain the original flavor and moisture of the food, but also prevent air from entering, so as to achieve freshness, and can be eaten together with the wrapping paper without polluting the environment. Its processing technology is as follows:
Grinding: After removing impurities, soybeans are crushed into coarse powder by a grinder, soaked in water, rinsed to remove the bean skin, soaked at room temperature for 4 hours to 8 hours, and ground.
Sieve: under constant stirring, pass through a 100-mesh sieve, and beat it into the gelatinization pot with a syringe pump.
Preparation of phospholipid emulsion: firstly prepare 1%-2% caustic soda solution, then heat to 85-100 ℃, add phospholipid (the amount of caustic soda is 0.8%-1.8% of phospholipid) while stirring, so that all phospholipids are dissolved in lye Then let it cool to 30-40 ℃ naturally, pass through a 100-mesh sieve, and prepare a phospholipid emulsion with a concentration of 1%-2%. The pH value of the prepared phospholipid emulsion should be between 8 and 9, which is weakly alkaline.
Paste mixing: After the above starch liquid is sent to the gelatinization pot, heated to 50°C, add an appropriate amount of hot phospholipid emulsion (preheated to 84-90°C) while stirring, and keep at 90°C for 2-3 hours. Made into starch protein paste. The stirring speed should be controlled at 40 rpm.
Frying film: The starch paste flows into the rotating copper belt of the film-frying machine through the feed tank, and scrapes out the paste film with a thickness of 2-3 silks. After drying at 40-45 °C, it is the finished food packaging paper. It should be noted that the steam pressure of the film frying machine should be controlled at 0.15-0.25 gauge pressure. If the pressure is too large, it is easy to cause many pores in the paste film, and if the pressure is too low, it is not easy to dry the paste film.
Since the moisture content of the wrapping paper is not less than 10%, steam should be sprayed into the film frying machine to adjust the humidity, which can prevent the paste film from becoming brittle after drying. In order to improve the strength of the wrapping paper, about 1.5% of alginate or about 1% of edible gelatin can be added to the paste before starch gelatinization. The purpose is to improve the toughness and strength of the finished paper. , its strength can be increased by about 10%.
