Study on the browning and structure properties of fresh-cut Chinese water chestnut ( Eleocharis tuberosa)

Abstract In this paper, the microstructure, water properties and browning control of Chinese water chestnut (CWC) after harvest were studied. Results showed that the tuber cell contained a large number of starch granules (5-10 μm for each one). The water-holding capacity of tuber cell was weak and T2 relaxation time was 28.5-75.6 ms. Sucrose was the main sugar component in Chinese water chestnut, which account for 84.8% of total sugar. In addition, potassium sorbate, green tea polyphenol and chitosan decreased the browning of fresh-cut CWC compared with the other anti-browning agents such as acetic acid, citric acid, oxalic acid, vitamin C and thyme oil. Moreover, chitosan coating combined with potassium sorbate and green tea polyphenol delayed weight loss and decay of fresh-cut tubers, also maintained a higher soluble solids and ascorbic acid content. The study provided an alternative method for controlling CWC browning, which would be helpful for the application of anti-browning agents in CWC processing.

摘要 本文研究了采后荸荠（Chinese water chestnut, CWC）的微观结构、水分特性及褐变防控效果。研究结果表明，其块茎细胞内含有大量淀粉颗粒，单颗粒粒径为5~10 μm。块茎细胞持水力较弱，T2弛豫时间区间为28.5~75.6 ms。蔗糖为荸荠的主要糖类组分，占总糖含量的84.8%。此外，相较于乙酸、柠檬酸、草酸、维生素C及百里香油等其他抗褐变剂，山梨酸钾、绿茶多酚与壳聚糖可显著减轻鲜切荸荠的褐变程度。进一步研究发现，壳聚糖涂膜联合山梨酸钾与绿茶多酚处理，可延缓鲜切块茎的失重与腐烂，同时维持较高水平的可溶性固形物与抗坏血酸含量。本研究为荸荠褐变防控提供了一种可行方案，有助于推动抗褐变剂在荸荠加工产业中的应用。