Analysis and control of microbial gas production in fermented chili paste

Abstract

In this work, the fermented chili pastes of normal samples (NS) and abnormal samples (ANS, aerogenic samples) were analyzed. The gas produced in the ANS was carbon dioxide. The kinds of bacteria genus were the same in both samples. However, concentrations of Bacillus and Clostridium in ANS were higher than those in NS. This finding indicated that they might be the potential bacteria for gas production. Gas-producing bacteria Bacillus amyloliquefaciens and Clostridium perfringens were isolated from the ANS. Antagonistic strain of Lactobacillus plantarum LM1-3 was isolated from the NS. Orthogonal experiment was performed to inhibit gas production using L. plantarum LM1-3 combined with NaCl and acetic acid. As a result, gas production could be inhibited under 30 °C for more than 30 days under the optimal composition of 12.00% NaCl, 2.7% acetic acid, and 105 CFU/g L. plantarum LM1-3. Otherwise, aerogenesis defect was observed at the 5th day in the control. Practical applications Many fermented chili paste products do not undergo sterilization with high temperature to ensure the natural flavor. Aerogenesis of fermented chili paste after packaging might happen. High salt and acid pressures are used to prevent aerogenesis, however, they will have a negative impact on taste under high concentration. Lactobacillus plantarum, which are generally recognized as safe, can not only inhibit aerogenesis, but also is recognized as a probiotic strain. Therefore, the composition of fermented chili paste was optimized by using acetic acid, salt, and L. plantarum that was isolated from fermented chili paste to inhibit the aerogenesis.