Enhancing the fermentation of unsalted Moroccan picholine green olives through heat-shock treatment, Lactiplantibacillus plantarum S61 inoculation and orange peel addition

Abstract

Table olives, a vital category among fermented vegetables, come in treated and natural forms. Treated green olives require an alkaline treatment before brining to start fermentation. This study investigates the fermentation of unsalted Moroccan Picholine green olives using a method that includes heat shock treatment, inoculation with Lactiplantibacillus plantarum S61, and orange peel juice. The findings indicate that a heat shock at 70°C significantly reduces enterobacteria and enhances acidification, dropping pH levels from 5.0 to 3.6. In contrast, non-heat-treated olives showed only a slight pH decrease. The method also exhibited high antimicrobial activity, with substantial inhibition of E. coli, P. aeruginosa, L. monocytogenes, and S. aureus. Antifungal activity was noted, with significant inhibition of various strains. These results suggest that combining heat shock, L. plantarum S61, and orange peel juice can significantly improve the fermentation process of green olives, enhancing safety and quality.