Zizania latifolia Cell Wall Polysaccharide Metabolism and Changes of Related Enzyme Activities during Postharvest Storage

Abstract

The metabolism of polysaccharides in the Zizania latifolia cell wall helps maintain the postharvest quality during storage. Fresh Z. latifolia was stored at 4 °C and 25 °C to evaluate the hardness, cell wall polysaccharide composition, cell wall structure, active ingredients, and cell wall metabolism-related enzyme activities. The results showed that hardness declined concomitantly with an increase in water-soluble pectin content during storage, as well as with a decrease in propectin and cellulose contents. Correlation analysis showed that lower activities of cell wall-degrading enzymes, such as polygalacturonase, cellulase, and β-galactosidase in Z. latifolia stored at 4 °C, were associated with lighter fiberization and greater hardness, compared with those stored at 25 °C. Additionally, the results of infrared spectroscopy showed that texture softening may be attributed to a decrease in the degree of esterification of water-soluble polysaccharides at 25 °C compared to that at 4 °C.