Bound Polyphenols from Insoluble Dietary Fiber of Defatted Rice Bran by Solid-State Fermentation with Trichoderma viride: Profile, Activity, and Release Mechanism

Abstract

This study is aimed at exploring the release of bound polyphenols (BP) from insoluble dietary fiber (IDF) and its mechanism by solid-state fermentation (SSF) via Trichoderma viride. The results indicated that BP released by SSF (5.55 mg GAE/g DW) was significantly higher than by alkaline hydrolysis. In addition, 39 polyphenols and catabolites were detected, and the related biotransformation pathways were speculated. Quantitative analysis showed that SSF released more ferulic acid, p-coumaric acid, and organic acids, which led to advances in antioxidant, α-amylase, and α-glucosidase inhibitory activities. Furthermore, structural characteristics (scanning electron microscopy, X-ray diffraction, thermos gravimetric analysis, and Fourier transform infrared spectroscopy) and dynamic changes of carbohydrate-hydrolyzing enzymes indicated that the destruction of hemicellulose and the secretion of xylanase were vital for releasing BP. Overall, this study demonstrated that SSF was beneficial to release BP from IDF, which could provide insight into utilizing agricultural byproducts in a more natural and economical way.

Hulless barley polyphenol extract inhibits adipogenesis in 3T3-L1 cells and obesity related-enzymes

“…Some authors have demonstrated the potential of natural phytochemicals, like phenolic compounds (3,7) and βcarotenoids (8), as promising anti-obesity drug-like candidates. Phenolic compounds are important secondary metabolites (9), widely distributed among cereals (10), vegetables (11), and fruits (12). Furthermore, polyphenols can be divided into phenolic acids, flavonoids, lignans, and stilbenes based on their structure.…”

Mixed solid-state fermentation for releasing bound polyphenols from insoluble dietary fiber in carrots via Trichoderma viride and Aspergillus niger

“…Recent studies have found that the activity of β-glucosidase is muffled under a single strain fermentation system, and lignin is hardly decomposed. 27 However, the addition of Aspergillus niger in this study compensated for the lack of ability to produce β-glucosidase, while the β-glucosidase in the system with significantly higher activity than other enzyme systems also indicated a clear correlation between the release of BP and the decomposition of lignin.…”

“…26 Compared with the solid fermentation of Trichoderma viride , the pathways involved in this study are more diversified, which also reflects the characteristics of MSF. 27…”

“…Compared to the former, the surface structure of MSF-IDF changed significantly, with a loose and porous honeycomb structure evident on its surface, and this became more severe with an increase in the fermentation time due to the presence of mould, exacerbating the disruption of the cell wall. 27…”

Structural, Physicochemical, and Functional Properties of Wheat Bran Insoluble Dietary Fiber Modified With Probiotic Fermentation

“…Modification of WB has been carried out to change its technological properties, improve its healthy benefits, or facilitate the preparation processes of foods such as bread ( 9 ). Fermentation has been regarded as a potential method of producing high-quality DF, playing an important role in improving its physicochemical properties or functional activities, such as WRC, WSC, ORC, and anti-diabetic effect ( 10 , 11 ). It was suggested that modification of millet bran DF through fermentation with Bacillus natto not only enhanced the proportion of SDF, but also increased the adsorption capacity of IDF for cholesterol, bile salts, nitrite, as well as glucose.…”