In the sensory quality of food, the texture (texture and physical properties) and taste of food are the most concerned by consumers. When designing the quality of frozen prepared food, we must fully consider meeting the above requirements of consumers. The factors that make up the taste are protein, carbohydrates, fat and water. The state of these substances in food determines the physical characteristics of food. The denaturation of protein during the freezing process is the main reason for the decline of its taste and taste, and the most effective way to minimize its negative effects is rapid low-temperature freezing. The frozen processing of rice products and starch products, because the main component of this kind of food is starch, will make the taste of food decline at low temperature because of starch aging, and 0℃ ~ 4℃ is the most aging temperature environment. Therefore, when this kind of food is frozen by the quick-freezing machine, it needs to quickly pass through the temperature zone where starch is easy to age and enter the quick-freezing temperature to complete the quick-freezing process. If there is a proper amount of liquid in rice, freezing will reach the quality of rice. Rice with liquid nitrogen as refrigerant has good freezing quality.
In recent years, many new types of prepared food freezing equipment have appeared at home and abroad, from the initial box-type quick freezing machine to various quick freezing equipment such as screw, liquid nitrogen, tunnel and flat plate. For the production of quick-frozen instant food, the current conveyor belt quick-freezing method still accounts for a large proportion because of its small size, short quick-freezing time, easy quick-freezing, improved product quality, improved production efficiency, saved energy and reduced production cost. At present, in order to pursue the efficiency of freezing production, many enterprises sometimes fail to reach the freezing temperature, resulting in unqualified products. The freezing time of food must depend on its kind and shape. From the surface and center of the product, we should take appropriate temperature and choose appropriate freezing conditions.
Freezing refers to using food without thawing after freezing.