College of Food Science and Technology, Shihezi University, Shihezi, Xinjiang, 832000, PR China; Research Center of Xinjiang Characteristic Fruit and Vegetable Storage and Processing Engineering, Ministry of Education, Shihezi, Xinjiang, 832000, PR China.
Institute of Agricultural Products Processing, Xinjiang Academy of Agricultural Reclamation Sciences, Shihezi, Xinjiang, 832000, PR China.
Plant Physiol Biochem. 2024 Oct;215:108984. doi: 10.1016/j.plaphy.2024.108984. Epub 2024 Aug 2.
The postharvest quality of winter jujubes is prone to deterioration, including inevitable pericarp reddening and rapid nutrient loss from the flesh, significantly impacting its edible quality and commercial value. As a crucial metabolic pathway in plants, phenylpropane metabolism not only regulates plant stress resistance but also closely relates to various coloration effects. In this study, we investigated the effects of luteolin solutions on postharvest color changes and phenylpropanoid metabolism in winter jujube. The results indicated that compared to the control group, winter jujube fruit treated with 200 mg L luteolin exhibited improved quality indexes, increased antioxidant capacity (capability of eliminating ABTS and DPPH radicals), and higher activities of antioxidant enzymes(superoxide dismutase (SOD), and catalase (CAT)). This led to a reduction in the oxidation of phenolic substances in winter jujube. Furthermore, luteolin treatment inhibited phenylpropanoid metabolism by suppressing the activities of 4-Coumarate: coenzyme A ligase (4CL), phenylalanine ammonilyase (PAL), and cinnamate 4 hydroxylase (C4H), as well as the expression of ZjUFGT, ZjDFT, and ZjPAL genes. Consequently, anthocyanin and quercetin synthesis were limited while the degradation rate of chlorophyll and carotenoid synthesis were slowed down after luteolin treatment. This resulted in delayed reddening of winter jujube following luteolin treatment. In conclusion, luteolin exhibits potential application prospects as a preservative for inhibiting reddening and browning in winter jujubes.
冬枣采后品质容易劣变，果皮不可避免地变红，果肉中营养物质迅速流失，严重影响其食用品质和商品价值。苯丙烷代谢作为植物中的一个关键代谢途径，不仅调控植物的抗逆性，而且与各种颜色变化效应密切相关。本研究探讨了芦丁溶液对冬枣采后颜色变化和苯丙烷代谢的影响。结果表明，与对照组相比，200mg/L 芦丁处理的冬枣果实品质指标得到改善，抗氧化能力（清除 ABTS 和 DPPH 自由基的能力）提高，抗氧化酶（超氧化物歧化酶（SOD）和过氧化氢酶（CAT））活性更高，导致冬枣中酚类物质氧化减少。此外，芦丁处理通过抑制 4-香豆酸：辅酶 A 连接酶（4CL）、苯丙氨酸解氨酶（PAL）和肉桂酸 4-羟化酶（C4H）的活性以及 ZjUFGT、ZjDFT 和 ZjPAL 基因的表达，抑制了苯丙烷代谢。因此，芦丁处理后，类黄酮和槲皮素的合成受到抑制，而叶绿素和类胡萝卜素的降解速度减缓，导致冬枣的变红延迟。综上所述，芦丁作为一种抑制冬枣变红和褐变的保鲜剂具有潜在的应用前景。
