Extraction process, physicochemical properties, and digestive performance of red yeast rice starch

AbstractIn the present study, taking red yeast rice (RYR) as the raw material, the optimum extraction process of RYR starch was investigated through a single-factor experiment and the Box –Behnken design: The liquid–to-solid ratio was 5 mL/g, the concentration of sodium hydroxide solution was 0.075 mol/L, and the extraction time was 3.1 h. Under these extraction conditions, the extraction rate of starch reached 90.077%. To explore the influence of solid-state fermentation on R YR starch, three different fermentation stages of RYR starch, raw rice starch, semi-gelatinized rice starch, and RYR starch were used as test materials to determine the changes in the physicochemical properties and glycemic index (GI) values of RYR starch during solid-state fermentation. The results showed that with the advancement of the RYR solid-state fermentation process, the starch particle size gradually increased, the light transmittance gradually decreased, and the solubility and swelling power significantly increased. In addition, the amylose content of starch gradually increased, whe reas the amylopectin content gradually decreased; the content of fast digestible starch and slow digestible starch decreased, whereas the content of resistant starch increased. In parallel, during solid-state fermentation, the hydrolysis index significantly decreased, and the GI values also decrease d. In summary, solid-state fermentation reduced the digestibility of RYR starch. These results provide a theo...
Source: Biotechnology and Applied Biochemistry - Category: Biochemistry Authors: Tags: ORIGINAL ARTICLE Source Type: research