Research On Control Of Spoilage Of Traditional Northeast Suancai By Using Lactic Acid Bacteria Preparation

The traditional northeast suancai is a traditional fermented food that is popular among people.The fresh-cut suancai is susceptible to spoilage and microbial contamination during the processing of the product.China GB 2760-2014 "Food Safety National Standards for the Use of Food Additives" stipulates that chemical preservatives are not allowed for fermented vegetables.The anti-corrosion problem of suancai in Northeast China greatly limits the development of the industry.This research aimed at the corruption of traditional fresh-smelling suancai products,and applied lactic acid bacteria biotechnology to control the growth and reproduction of spoilage bacteria in suancai.1.Four strains of spoilage bacteria W-1,GS-2,GS-3 and Z-4 were isolated from pickled vegetables.The molecular biological identification of 16 S rRNA showed that four strains of spoilage bacteria W-1 and Z-4 were Bacillus subtilis,GS-2 was Bacillus sp.,and GS-3 was Bacillus flexus.2.83 strains of lactic acid bacteria were isolated from the intestines of traditional pickled vegetables and fish,and the antagonistic strains STM1-3 and LJ2-2 against spoilage bacteria were screened.The strain STM1-3 was identified as Lactobacillus plantarum and the strain LJ2-2 as Lactobacillus sp.by morphological,physiological and biochemical reactions and 16 S rRNA identification.3.The strain STM1-3 was used as a biological preservative to optimize the fermentation medium.When the sucrose was 20.0 g/L and the soy peptone was 15.0 g/L,the strain STM1-3 had the best growth effect.The ?OD600 of the 24 h culture was 1.299.The strain STM1-3 lyophilized preparation was obtained by vacuum freeze-drying.Adding the strain STM1-3 lyophilized preparation to the fresh-cut suancai product for application research can extend the shelf life of the product for 100 days.