Abstract
Sargassum fusiforme is an abundant source of biologically active compounds that are released during fermentation. However, the effects of Lactobacillus fermentation on the nutrient composition of S. fusiforme have yet to be sufficiently determined. In this study, we used five strains of Lactobacillus to ferment S. fusiforme and examined changes in the bioactive components, volatile compounds, and bioactivities of the fermentation supernatants. Among the assessed strains, fermentation with Lactobacillus delbrueckii promoted significant increases in the total phenolic contents, and fermentation with all strains contributed to reductions in the levels of undesirable volatile compounds associated with the characteristic odor of S. fusiforme. In addition, S. fusiforme fermented using L. delbrueckii showed superior ABTS radical scavenging activity, whereas S. fusiforme fermented using L. plantarum FY03 (PF-3) or L. plantarum FY02 (PF-2) showed enhanced DPPH radical scavenging capacity, and fermentation using L. rhamnosus promoted the highest ferric-ion-reducing power. Moreover, the inhibition of α-glucosidase activity increased by 2.0- to 3.0-fold in fermented S. fusiforme, whereas the inhibition of α-amylase activity was only significantly augmented by the PF-2 and PF-3 strains. These findings highlight the potential health benefits of Lactobacillus-fermented S. fusiforme, particularly the enhanced antioxidant activities and the capacity to inhibit α-glucosidase and α-amylase activities.