Development of yacon syrup fermented by Lactiplantibacillus plantarum NCU001043: Metabolite profiling, antioxidant and glycosidase inhibition activity

The effects of Lactiplantibacillus plantarum NCU001043 fermentation on the physicochemical and biological properties of yacon tubers were investigated. The fermentation parameters were first optimized by single-factor tests, then an orthogonal experimental design, which resulted in production of a fermented yacon syrup with excellent sensory attributes and increased antimicrobial activity against Helicobacter pylori. The physicochemical characteristics of the yacon syrup were determined after fermentation under the optimum conditions. Although the total phenolic content of the fermented yacon syrup decreased after fermentation, its antioxidant capacity and glycosidase inhibition activity increased. Spearman correlation analysis indicated that one of the phenolic compounds, 4-hexyloxyphenol, might be the main α-amylase and α-glucosidase inhibitor. Molecular docking indicated that 4-hexyloxyphenol has a strong binding affinity for the active-sites of both enzymes. These findings will facilitate the development of yacon-based functional foods by microbial fermentation and application of Lactiplantibacillus plantarum NCU001043 in food fermentation.