With the improvement of living standards, frozen food has more and more entered the lives of ordinary people. Quick-frozen aquatic products, quick-frozen livestock and poultry meat, various quick-frozen vegetables and quick-frozen prepared food are no longer strange to people. However, many people still have many doubts about the hygienic status and nutritional value of such foods.
First, we should distinguish three concepts, namely frozen food, quick frozen food and general frozen food. According to the "Technical Regulations for Quick-frozen Foods" approved in 1988 in China, foods with a freezing temperature below -30 ℃ are called quick-frozen foods, and foods with a freezing temperature of -18 ℃ -23 ℃ are called frozen foods. Generally speaking, the ice crystals generated during the freezing process are the main factors affecting the quality of frozen foods. Frozen foods and quick-frozen foods are pre-treated foods that quickly pass through the maximum ice crystal area of -1 ℃ -5 ℃ within 30 minutes. , And then preserve and transport the food under -18 ℃. Because frozen food and quick-frozen food have a lot in common, people often call it "quick-frozen food" in general.
Quick-frozen food must meet the following conditions:
1. Fresh food is processed to meet food hygiene standards;
2. Use quick freezing method to freeze;
3. Comes with packaging and labels that meet the requirements. These requirements are the difference between quick-frozen food and general frozen food.
No loss of nutrition in quick-frozen food
In layman's terms, quick-frozen foods are frozen in an environment of minus 30 to 35 degrees , and the freezing process is completed in about 15 minutes, so that the frozen food reaches minus 18 degrees.
In real life, the foods that we commonly handle in cold storage and refrigerators are often frozen for 90 minutes, which is called slow-frozen food.
The difference between quick-frozen food and slow-frozen food is that the cells of quick-frozen food are less likely to deform, and the water and juice in the food tissue are not lost. The quick-freezing treatment avoids the degradation of food quality caused by slow-frozen food during long-term freezing.
The production, processing, transportation, and sales of quick-frozen food have strict requirements on temperature, and must be maintained at minus 18 degrees. Because only below minus 18 degrees, bacteria and various enzymes will be in a completely inhibited state, preventing food from spoiling, and keeping the original freshness and nutrients of the food from being lost.
Nutrition experts believe that in addition to maintaining the flavor of traditional snacks, quick-frozen food is currently the best in terms of maintaining nutrition. Compared with other food storage methods, except for protein and fat, there will be no changes, including trace elements and constant Elements and vitamins are retained.
So, what should you pay attention to when purchasing and eating quick-frozen food? When purchasing quick-frozen foods, you should choose products with complete packaging specifications and complete items; choose products with natural white color, no discoloration, and no dullness; choose products with clear labels, shelf life, and production dates.