[关键词]
[摘要]
本文研究了1-甲基环丙烯(1-methylcyclopropene,1-MCP)处理延缓龙眼采后贮藏期间果皮中的膜脂代谢,分析其耐贮性。选取福眼龙眼,经1-MCP处理后,检测果皮脂酶、脂氧合酶(Lipoxygenase,LOX)、磷脂酶D(Phospholipase D,PLD)、磷脂酰胆碱(Phosphatidylcholine,PC)、磷脂酰肌醇(Phosphatidylinositol,PI)、丙酮酸(Pyruvic acid,PA)的含量,高效液相色谱-四级杆飞行时间串联质谱技术分析油酸、亚油酸、亚麻酸、肉豆蔻酸、棕榈酸、硬脂酸膜脂等脂肪酸组分。结果表明,对照组和实验组的果皮脂酶、LOX、PLD活力随贮藏时间的延长均升高,PC、PI含量随贮藏时间的延长均下降。实验组在采后0~6 d内,龙眼果皮LOX、脂酶、PLD活力、PC、PI、PA含量、油酸、亚油酸、亚麻酸含量高于对照组,肉豆蔻酸、棕榈酸、硬脂酸含量与对照组采后0~6 d相比降低,差异具有统计学意义(p<0.05)。实验组经1-MCP处理,在采后6 d脂酶、LOX和PLD的活力分别为25.62 U/mg、12.62 U/mg、和0.80 U/mg,PC、PI和PA的含量分别为0.39 mg/g、0.22 mg/g、和0.52 mg/g。说明1-MCP能有效降低采后龙眼贮藏期间果皮中的LOX、脂酶、PLD活力,促进PC、PI等磷脂组分含量升高,抑制磷脂降解产物PA产生,从而能抑制果皮膜的生理代谢,维持细胞膜系统结构的稳定,延长龙眼的贮藏时间。
[Key word]
[Abstract]
The storability of longan fruits of the “Fuyan” cultivar was investigated by subjecting them to 1-methylcyclopropene (1-MCP) treatment to delay membrane lipid metabolism in the pericarp during postharvest storage. After 1-MCP treatment, the activities of lipase, lipoxygenase (LOX), and phospholipase D (PLD) and the contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and pyruvic acid (PA) in the pericarp were measured. Fatty acid components, such as oleic acid, linoleic acid, linolenic acid, myristic acid, palmitic acid, and stearic acid in the cell membranes of the pericarps were analyzed by HPLC-Q-TOF-MS/MS. Results indicated that with the prolongation of storage, the activities of lipase, LOX, and PLD in the control and experimental groups increased, whereas the contents of PC and PI decreased. Within zero to six days after harvest, the experimental group had higher activities of lipase, LOX, and PLD, higher contents of PC, PI, PA, oleic acid, linoleic acid, and linolenic acid, and lower contents of myristic acid, palmitic acid, and stearic acid compared with the control group, with differences being statistically significant (p < 0.05). Six days after harvesting, the activities of lipase, LOX, and PLD were 25.62 U/mg, 12.62 U/mg, and 0.80 U/mg, respectively, and the respective contents of PC, PI, and PA were 0.39 mg/g, 0.22 mg/g, and 0.52 mg/g in the experimental group. The results indicated that 1-MCP effectively reduced the activities of lipase, LOX, and PLD, promoting an increase in the contents of phospholipid components, such as PC and PI, and inhibited the production of the phospholipid degradation product PA in the longan pericarp during postharvest storage. This led to the inhibition of physiological metabolism in the cell membrane of the pericarp, thereby maintaining the stability of the cell membrane system and enabling the prolongation of the storage life of longan fruits.
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[基金项目]
国家自然科学基金项目(21667029);新疆工程学院科研基金项目(2017xgy101910);新疆工程学院科研育人项目(2019xgy112112)