红肉蜜柚汁胞枯水特性分析

Characteristics of Granulated Juice Sacs of Red-Fleshed Sweet Pomelo

研究红肉蜜柚果实中正常汁胞、半枯水汁胞和全枯水汁胞外观及若干生理生化指标的差异。结果表明,与正常汁胞相比,随着枯水程度的加重,红肉蜜柚果实汁胞的干物质、总糖、可滴定酸、VC、红色素、总酚含量减少,鲜质量、还原糖、蛋白质含量略有增加后再下降,汁胞的营养品质明显降低。汁胞的超氧化物歧化酶、过氧化物酶、过氧化氢酶的活性变化不同步,多酚氧化酶活性明显下降,导致丙二醛、木质素含量不断增加,汁胞呈现枯水的典型症状。

The appearance, physiological and biochemical differences among normal juice sacs, granulating juice sacs and granulated juice sacs of red-fleshed sweet pomelo(Citrus grandis) were investigated in this study. The results showed that the contents of dry matter and total sugars, titratable acid, vitamin C, red pigments and total phenolic in granulated juice sacs gradually decreased with the extent of granulation. The fresh weight and the contents of reducing sugar and protein first increased and then declined, which lowered the nutritional quality of juice sacs. The enzymes activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) changed disorderly and polyphenoloxidase(PPO) activity significantly decreased, resulting in an increase in malondialdehyde(MDA) content and lignin synthesis, which finally caused granulation of juice sacs of red-fleshed sweet pomelo.