Changes in nutrition and related enzymes of Annona squamosa during storage based on carbohydrate analysis

Firmness and soluble solids content in Annona squamosa during storage were studied. Changes in total Annona squamosa polysaccharides (TASP) obtained by alcohol precipitation and corresponding ethanol supernatants (TASP-S) during storage were analyzed. Ethanol supernatants from Annona squamosa stored for 3 days (TASP-S3) were chosen and small molecule carbohydrate (TASP-S3-1) in it was characterized in structure. Activities of related enzyme during storage were determined. Results indicated firmness exhibited a significant decline from 1 day to 3 days and soluble solids content fluctuated during storage. With prolonged storage time, relative content of each component in TASP varied and that of carbohydrate with higher molecular weight gradually decreased. So was the compositions in TASP-S during storage. TASP-S3-1 was ultimately identified to be saccharose. Enzyme assays indicated activities of related enzymes varied during storage, and acid invertase, sucrose synthase might play more important roles in improving the quality and nutrition of postharvest Annona squamosa. Practical applicationsThis work lay the foundation for further studying carbohydrate metabolism and controlling the quality of postharvest Annona squamosa. Because the relative contents of each components in TASP and TASP-S, changed with the extension of storage time. Besides, among these related enzymes, acid invertase and sucrose synthase would be more important in postharvest Annona squamosa, which provided critical information on improving the quality and nutrition of Annona squamosa in further study.