Introduction to hairy crabs
Hairy crab (Eriocheir sinensis) ( Eriocheir sinensis ) is native to rivers and estuaries along the Yellow Sea. It has now spread throughout Europe and California. Although the Chinese mitten crab is considered a nuisance invasive species in Europe and the United States, it constitutes a promising freshwater fishery industry in China. China's annual production has increased over the past decade, from 200,000 tons in 2000 to 420,000 tons in 2004. As a result, hairy crabs have become a common food today.
The best crabs are available in the fall as they store up enough energy for the coming winter. Hairy crabs are a traditional salty food in China. Crabs are not only delicious and unique in aroma, but also have good nutritional value.
Crab meat is an excellent source of minerals, especially calcium, iron, zinc, potassium and phosphorus.
Protein is an essential nutrient for humans. Essential amino acid composition is one of the most important nutritional qualities of protein. Amino acid scoring is a method of assessing protein quality by comparing the amino acid pattern of a test protein to that of a reference protein. Once the amino acid score is derived, compare it to the preschooler's amino acid needs. The rationale for using this age group requirement is that if a protein is effective in supporting growth and development in young children, it will meet or exceed the needs of older children and adults. Amino acid scores are widely used to assess the nutritional quality of proteins.
The nutritional quality of fish is largely related to the content of essential fatty acids (EFA), namely α-linolenic acid (ALA, 18:3 n − 3), linolenic acid ( LA , 18:2 n − 6)) and other omega-3 polyunsaturated fatty acids ( n − 3 PUFA). ALA is a precursor to the n − 3 family eicosapentaenoic acid (EPA, 20:5 n − 3) or docosahexaenoic acid (DHA, 22:6 n − 3), while LA is arachidonic acid acid (AA, 20:4 n − 6), which is the main precursor of eicosanoids. AA and DHA are the main components of cell membrane phospholipids and the main long-chain PUFAs of the central nervous system. Long-chain polyunsaturated fatty acids accumulate rapidly in the brain during the period of maximum brain growth, which lasts from the last trimester of pregnancy to approximately two years of age in humans. High AA may promote the onset of many diseases, such as Crohn's disease and inflammatory diseases. Seafood is a rich source of n -3 PUFA, and most marine oils are good sources of EPA and DHA. Multiple studies have shown that consuming foods containing long-chain n -3 fatty acids (such as EPA and DHA) is associated with a lower risk of coronary heart disease and cancer.
Nutritional quality of adult male mitten crabs of different grades
Effects of different grades on male chemical composition, fatty acid and amino acid content. Grade III male Chinese monitor lizard (150-174 grams) is rich in balanced EAA ingredients and meets human needs for amino acids. In addition, the second-grade male Eucalyptus sinensis (175-199 grams) has the best fatty acid nutrition. There were no significant differences in the tissue indicators, total edible yield and approximate chemical composition of crabs of different grades. Overall, it can be concluded that although not the largest in size, male Eucalyptus sinensis weighing 150-200g has the highest nutritional quality. Male E. sinensis 150-200 g weight (Grade II-III) is recommended as it shows better nutritional qualities.
