1. Material selection. The raw materials for processing quick-frozen fruits and vegetables should be fully ripe. The color, aroma and taste can be fully displayed. The texture is brittle, without pests and diseases, mildew, aging and yellowing, and without mechanical damage. Fresh fruits and vegetables should be used as processing raw materials. It is best to harvest and process in time on the same day to ensure product quality.
2. Precooling. Freshly harvested fruits and vegetables generally contain atmospheric heat and released respiratory heat. In order to ensure rapid freezing, pre-cooling must be carried out before quick freezing. The method includes air cooling and cold water cooling. The former can be cooled by blower, and the latter can be cooled by cold water immersion or spraying directly.
3. Cleaning. Dust, sediment and dirt are usually attached to the surface of harvested fruits and vegetables. In order to ensure that the products meet the food hygiene standards, they must be cleaned before freezing. Especially the quick-frozen fruits and vegetables should be so, because the quick-frozen products are no longer washed when eating, so this cleaning is very important and must not be neglected. In addition to manual cleaning, washing machine (such as rotary drum, vibrating mesh belt washing machine) or high-pressure sprinkler can also be used for washing.