Enhancement of non-glycoside phytoestrogens and digestive enzymatic inhibition activity during bioprocessing of isoflavone-enriched soybean leaves by mycelia of Tricholoma matsutake

Abstract

This study aimed to examine the effects of bioprocessing on the bioactive components of isoflavone-enriched soybean leaves (IESLs) using Tricholoma matsutake mycelia. To optimize fermentation conditions, various brown rice ratios and fermentation periods were compared. Subsequently, a ratio of 8:2 (aglycones: 1873.57 μg/g) soybean leaves to brown rice and a fermentation period of 8 days (aglycones: 3623.58 μg/g) were determined to be optimal for efficient fermentation conditions. Isoflavone derivatives were altered throughout the bioprocessing process, with the fermentation stage indicating a bioconversion to isoflavone-aglycones. Using time-of-flight mass spectrometry, twenty functional metabolites were identified. The heat maps indicated a significant concentration of glycoside phytoestrogens at the fermentation stage during bioprocessing. The highest levels of total phenolics (8.49 GAE mg/g), total flavonoids (2.87 RE mg/g), and digestive enzymatic inhibitory activities (1 mg/mL; α-glucosidase 73.25%, pancreatic-lipase 58.26%) were seen in fermented IESLs. This study discovered that bioprocessing IESLs with T. matsutake mycelia has the potential to enhance aglycone phytochemicals in the bioproducts. © 2024