The enhancement mechanism of adding stachyose to Lactiplantibacillus plantarum SS-128 in the probiotic/prebiotic combination biopreservation in salmon

Lactiplantibacillus plantarum SS-128 (SS-128) is a biocontrol bacterium used to preserve food freshness. However, its performance with aquatic products is limited due to unstable adhesion. This study investigated how stachyose affects SS-128's growth, acid production, and biofilm formation, and explored the preservation mechanism of the probiotic/prebiotic combination as a biocontrol agent. Stachyose shortened the lag phase of SS-128 growth and gave it a competitive advantage over other microorganisms. It greatly enhanced SS-128's acid production, lowering the environmental pH and inhibiting spoilage bacteria growth. Additionally, stachyose increased SS-128's biofilm production by 74% and increased its adhesion to the surface of aquatic products. Using this probiotic/prebiotic combination, the shelf life of salmon was extended from 4 to 8 days. On the 8th day of storage, the TVB-N (Total Volatile Basic Nitrogen) values of the LAB/Stachyose group remained within the acceptable range at 0.28 g N/kg. This demonstrates that stachyose significantly contributes to SS-128's biopreservation effect. Thus, this probiotic/prebiotic combination had great potential for application in other aquatic products and the broader food industry.