Sarcoplasmic Protein Hydrolysis Activity ofLactobacillus plantarum120 Isolated from Suanyu: A Traditional Chinese Low Salt Fermented Fish

Abstract

The hydrolysis of sarcoplasmic proteins during the growth of Lactobacillus plantarum 120 originally isolated from Suanyu, a traditional Chinese low salt fermented fish, was evaluated. Fermentation was carried out in a fish meat model system at 30C for 96 h. Proteolytic activity of this strain on fish muscle sarcoplasmic protein was determined by proteins, peptides and free amino acids analyses. There was a pronounced hydrolysis of almost all protein bands in electrophoretic pattern by L. plantarum 120. It also resulted in the generation of new peptides and disappearance of original peaks. In addition, the studied strain generated greater amounts of free amino acids than the control, especially for alanine, glutamic acid, phenylalanine, valine, methionine, aspartic acid, isoleucine and leucine. In general, proteolysis of fish sarcoplasmic proteins by L. plantarum 120 occurred during fermentation, resulting in increase in peptides and free amino acids, which may contribute to the taste and aroma of Suanyu. Practical Applications Suanyu is one of the Chinese traditional fermented fish products in South China. According to its characteristic flavor and high nutrition value, Suanyu has been accepted around China in recent year. However, Suanyu is still manufactured on a small scale by spontaneous fermentation. It is difficult to guarantee product quality and increase the efficiency. Lactic acid bacteria is one of the essential agents of the meat fermentation process that contribute to the hygienic and sensory qualities of meat products. Lactobacillus plantarum 120, isolated from Suanyu, exhibited optimal properties as a potential starter in our previous work. Once L. plantarum 120 is used as an industrial starter, it will promote fish muscle proteolysis, shorten the fermentation period and then improve product quality assurance activity.