Zhang Weida, Guo Minrui, Yang Wanting, Liu Yuxing, Wang Yue, Chen Guogang
College of Food Science and Technology, Shihezi University, Shihezi 832000, China.
Foods. 2022 Mar 15;11(6):841. doi: 10.3390/foods11060841.
To investigate the physiological and molecular properties relating to cell wall carbohydrate metabolism in fruit, the ultrastructure and polysaccharides compositions of the cell wall, as well as the fruit quality and activities of enzymes relating to fruit softening, were studied for three Hami melon varieties ('Xizhoumi 17', 'Jinhuami 25', and 'Chougua') representing three different storability levels. The results showed that 'Chougua' maintained a higher firmness on day 18, with the lowest decay incidence (0%). 'Chougua' showed a better storage quality and intact cell wall structure. The molecular weight and monosaccharide composition of cell wall polysaccharides for Hami melons underwent great changes during storage, and the degradation of pectin polysaccharides was obvious, involving the depolymerization of macromolecular polymers accompanied by the production of new macromolecular polymers and composition changes in pectin monosaccharides (glucose, galactose, and arabinose) during the softening process of the Hami melons. Polygalacturonase, pectin methylesterase, xyloglucan endo-transglycosylase/hydrolase, α-arabinofuranosidase, β-galactosidase, and cellulase were associated with fruit softening at different stages of storage. There were similar softening mechanisms in the three Hami melons. This study will provide reference for further study on the fruit softening mechanisms of Hami melons.
为研究果实细胞壁碳水化合物代谢相关的生理和分子特性，以代表三种不同耐贮性水平的三个哈密瓜品种（‘西州蜜17’、‘金蜜25’和‘丑瓜’）为材料，研究了细胞壁的超微结构和多糖组成，以及果实品质和与果实软化相关的酶活性。结果表明，‘丑瓜’在第18天保持较高的硬度，腐烂发生率最低（0%）。‘丑瓜’表现出较好的贮藏品质和完整的细胞壁结构。哈密瓜细胞壁多糖的分子量和单糖组成在贮藏期间发生了很大变化，果胶多糖的降解明显，在哈密瓜软化过程中涉及大分子聚合物的解聚，伴随着新大分子聚合物的产生以及果胶单糖（葡萄糖、半乳糖和阿拉伯糖）组成的变化。多聚半乳糖醛酸酶、果胶甲酯酶、木葡聚糖内转糖苷酶/水解酶、α-阿拉伯呋喃糖苷酶、β-半乳糖苷酶和纤维素酶与贮藏不同阶段的果实软化有关。三个哈密瓜具有相似的软化机制。本研究将为进一步研究哈密瓜果实软化机制提供参考。
