1.The Experimental Teaching Center of Traditional Chinese Medicine and Biotechnology, Beijing City University, Beijing 100094, China; 2.Beijing Key Laboratory of Meat Processing Technology, China Meat Research Center, Beijing 100068, China
Abstract:The pattern of proteolysis in air-dried sausages during processing and storage was analyzed by the detection of total nitrogen (TN), non-protein nitrogen (NPN), amino acid nitrogen (AAN), total volatile basic nitrogen (TVB-N), free amino acids (FAA), and various proteins (sarcoplasmin, myofibrillar protein, alkali-soluble protein and alkali-insoluble protein). The results showed that the TN content did not change significantly during processing and storage. The NPN content increased from 469.4 mg/100 g in raw meat to 786.4 mg/100 g in sausages, and then to 1 256.1 mg/100 g after 240 days of storage. The contents of peptide nitrogen and AAN continued to increase during processing and storage. The content of TVB-N did not change significantly during the air-drying process, but increased rapidly after 180 days of storage. The contents of most of the FAA in raw meat increased after being processed into sausages and gradually increased during storage, while only cysteine content reduced significantly. During processing, both the contents of sarcoplasmic and myofibrillar proteins decreased due to degradation, while the content of matrix protein significantly rose. During the storage process, the content of sarcoplasmic protein continued to decrease, while the content of myofibrillar proteins showed no significant change in the first 180 days and decreased significantly on day 240, and the content of matrix proteins showed no significant change over the entire storage period.