Effect of POF shrink film on vegetable transportation

Vegetables and fruits are easy to rot during transportation, so why can we see intact vegetables and fruits in markets and shopping malls? That is, POF shrink film plays a very good role in protecting product packaging.

Broccoli has a high respiratory intensity and vigorous physiological and metabolic activities after harvest. It will lose water and turn yellow in a short time, which will affect the commodity value of vegetables. Therefore, vegetables must be precooled in time after harvest, quickly remove the field heat, and reduce the central temperature and respiratory intensity of broccoli, so as to slow down the metabolic activity of vegetables and prolong the fresh-keeping period. At present, the pre-cooling links in domestic vegetable producing areas are weak, lacking professional pre-cooling facilities; Refrigerated transportation is rarely used during transportation. Farmers' markets, supermarkets and other retail links mostly sell fruits and vegetables at room temperature without packaging. The facilities for selling fruits and vegetables are basically ordinary shelves, ordinary shelves with spraying devices (RH: 80% ~ 90%) and refrigerated display cases (2 ~ 10℃). The rotting rate of vegetable circulation in China is 25% ~ 30%, which is the current situation of vegetable circulation in China.

Do a simple experiment: choose fresh, clean, uniform size, 15 ~ 20 cm in diameter and 15～20cm long broccoli (a single weight of about 200), study pressure difference pre-cooling and cold storage pre-cooling, store it in polystyrene foam box with ice at 0℃ for one day, pack it with POF shrink film at 4℃ and 20℃ and without POF shrink film, and humidify it at 20℃ for two days. The results show that the precooling speed of pressure difference precooling broccoli is faster than that of cold storage. The quality of broccoli sold at 4℃ is better than that sold at 20℃ after being transported in polystyrene foam box with ice storage for 1 day.