Frozen foods, also known as frozen meals, are food products that are processed and preserved through rapid freezing at extremely low temperatures. This method is a significant advancement in food processing technology, differing from traditional refrigeration methods. The key characteristic of frozen food is that it undergoes washing, blanching, cooking, or other preparatory steps before being quickly frozen at temperatures below -33°C. Within 30 minutes, the product's temperature passes through the critical range of -1°C to 11°C—known as the maximum ice crystal formation zone, where over 80% of the water content turns into ice. After freezing, the ice crystals formed are smaller than 10 micrometers, and the core temperature drops below -18°C for safe storage and transportation.
Compared to other types of food, frozen foods offer several advantages:
First, they maintain high quality and safety. Quick-freezing at low temperatures helps preserve the color, taste, and nutritional value of the food while effectively inhibiting microbial growth, ensuring food safety.
Second, frozen foods can be nutritionally tailored. By combining different ingredients, manufacturers can control fat, calorie, and cholesterol levels to meet diverse consumer needs.
Third, there is a wide variety of frozen food products. Frozen foods fall into four main categories, with more than 3,000 varieties available, ranging from non-staple items to staple foods, dishes, and snacks. This diversity makes them an ideal option for people who lack cooking skills.
Fourth, they are convenient to use. Frozen foods help balance seasonal supply and demand, reduce household workload, minimize urban waste, and contribute to environmental protection.
Fifth, they are cost-effective. Compared to canned foods, frozen foods retain better freshness and consume about 30% less energy during production.
Frozen foods are generally categorized into four groups: quick-frozen fruits and vegetables, quick-frozen meat and poultry, quick-frozen seafood, and ready-to-eat frozen meals. Examples include frozen green beans, broccoli, strawberries, shrimp, fish, dumplings, pizzas, and many other prepared dishes.
The development of frozen foods has a long history. Originating in the United States in 1928, the industry initially faced slow growth due to a lack of consumer awareness. However, after World War II, it began to flourish. In the late 1940s, the U.S. conducted systematic research on frozen foods, introducing the famous T-T-T concept (Time, Temperature, and Treatment) and establishing regulations for frozen food production. This led to industrial-scale production and widespread consumer acceptance. With advancements in individual freezing technology, frozen foods expanded globally and now account for over 3,000 varieties worldwide. In developed countries, frozen foods have become the fastest-growing segment, expected to make up 60%-70% of all food sales, surpassing canned foods in popularity.
In China, frozen food production started later, but it has grown significantly over the past 30 years. Initially, frozen foods were produced mainly for export by coastal canneries, often using cold storage instead of proper freezing techniques. Due to limited refrigeration capacity, most products were "slow-frozen," leading to slow development. In 1973, three Chinese cities introduced spiral freezers from Japan, boosting the industry. Today, China produces over 10 million tons of frozen food annually, with nearly 200 companies and more than 300 varieties. Export volumes have reached 500,000 tons, and China leads the world in quick-frozen convenience food exports.
Despite this progress, China still faces challenges. The quantity and variety of frozen foods remain insufficient to meet market demand. Processing technologies lag behind international standards, and the cold chain infrastructure is underdeveloped. Most frozen food machinery is imported, limiting the industry's ability to fully adapt to growing demands. To keep up with global trends, further investment in technology and infrastructure is essential.
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