Extraction temperature affects the activities of antioxidation, carbohydrate-digestion enzymes, and angiotensin-converting enzyme of Pleurotus citrinopileatus extract

Extraction temperature can potentially affect the chemical compositions and bioactivities of the extracts obtained. The objective of this study was to investigate the effect of extraction temperature on the distribution of bioactive compounds and the bioactivities of Pleurotus citrinopileatus. The antioxidant activities (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(+) scavenging capabilities) and the inhibitory capabilities on pancreatic alpha-amylase, intestinal alpha-glucosidase, and hypertension linked angiotensin-converting enzyme of hot water P. citrinopileatus extract and cold water P. citrinopileatus extract were determined. The results showed that the antioxidant capabilities and inhibitory effects on alpha-amylase, alpha-glucosidase, and angiotensin-converting enzyme of cold water P. citrinopileatus extract were significantly higher than those of hot water P. citrinopileatus extract. The cold water P. citrinopileatus extracted was further precipitated with 100% ammonium sulfate to obtain a polysaccharide fraction or with 75% ethanol to obtain a protein fraction. The inhibitory activities of the protein fraction of the cold water P. citrinopileatus extract on alpha-amylase, alpha-glucosidase, and angiotensin-converting enzyme were significantly higher than those of the polysaccharide fraction. In conclusion, the protein fraction of the cold water P. citrinopileatus extract could be responsible for its bioactivities. Copyright (C) 2016, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan LLC.