This study aims to evaluate the effects of different cascara particle sizes and variations in the kombucha fermentation process on the bioactive compounds and antioxidant properties of cascara (Coffea arabica L.) kombucha. Cascara tea (CT), cascara tea with sugar (CS), and cascara kombucha (CK) were prepared using whole, coarsely ground, and finely ground cascara. A finer particle size enhanced color intensity and improved the extraction of bioactive compounds. CK prepared with finely ground cascara demonstrated the highest total phenolic content (TPC), total flavonoid content (TFC), and ferric reducing antioxidant power (FRAP). Fermentation influenced the profile of phenolic acids, leading to a decline in most compounds, except for vanillic acid in all CK samples, which increased during fermentation. Interestingly, apigenin levels increased, while quercetin levels decreased throughout fermentation. These findings highlight the role of fermentation, sugar addition, and particle size reduction in enhancing phenolic extraction and antioxidant potential in cascara-based beverages, particularly cascara kombucha.
Proteins from the bran of Khao Dawk Mali 105 rice at two maturity stages, green (GB) and fully ripe (RB), were extracted using single and sequential enzyme-assisted processes. Non-enzymatic extraction (control), α-amylase (AA), protease (PT), and two sequential treatments (AA-PT and PT-AA) were applied to defatted bran to evaluate their effects on protein yield, structural attributes, and functional properties. Protease-based extractions, particularly PT, produced the highest protein contents (28% in GB and 23% in RB) and significantly improved solubility, water- and oil-holding capacities, and foaming performance. GB extracts consistently outperformed RB across all functional and antioxidant measurements, indicating greater extractability and bioactive potential in green rice bran. Enzymatic hydrolysis also enhanced phenolic and flavonoid release, leading to markedly higher DPPH and FRAP activities. SDS-PAGE profiles demonstrated reduced band complexity and lower-molecular-weight protein in enzymatically treated samples, while FTIR spectra confirmed secondary structural modifications associated with hydrolysis. Overall, protease and sequential assisted extractions provide an efficient and sustainable approach to improving rice bran protein recovery and functionality. These findings highlight green rice bran as a promising source of high-value plant proteins for food and nutraceutical applications.