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为进一步明确‘金川雪梨’采后货架期间果实褐变过程中内在品质和相关生理代谢途径变化规律,补充完善‘金川雪梨’黑心病发生机理和调控途径,以同期采收黄皮果实和绿皮果实为试材,于室温(20±0.5)℃下,调查测定货架0 d和10 d果实组织褐变指数,系统分析比较二者主要品质指标、生理代谢等变化的差异。结果表明:黄皮果实货架0 d和10 d,其果心和果肉组织褐变指数显著高于绿皮果实;货架10 d时,与绿皮果实相比,其可溶性固形物、可滴定酸含量及果实硬度均显著降低;果肉组织乙醇和乙醛含量显著升高;过氧化物酶(POD)、超氧化物歧化酶(SOD)及过氧化氢酶(CAT)等主要抗氧化酶活性降低;丙二醛含量升高,可溶性蛋白含量降低,细胞相对电导率显著升高;多酚氧化酶(PPO)活性相对较高,总酚含量下降;货架期间黄皮果实呼吸强度和乙烯释放速率均显著高于绿皮果实。因此,‘金川雪梨’黄皮果实采后乙烯和呼吸代谢旺盛,加速了果实衰老,果实乙醇、乙醛等发酵代谢产物积累,抗氧化酶活性降低,膜质过氧化水平加重,PPO催化酚类底物氧化,进而导致‘金川雪梨’果实黑心等组织褐变发生。
In order to further clarify the changes of internal quality and related physiological metabolic pathways during the fruit browning process of ’Jinchuan Sydney’ during the post-harvest shelf period, and to complement and improve the pathogenesis and regulation of black heart disease in Jinchuan Sydney, The fruits were used as test materials to measure the browning index of fruit tissues on 0 and 10 d at room temperature (20 ± 0.5) ℃. The differences of the main quality indexes and physiological metabolism between the two fruits were systematically analyzed and compared. The results showed that the browning index of fruit core and flesh tissue was significantly higher than that of green fruit on the 0 d and 10 d shelf of shelled yellow peel. Compared with green peel, the soluble solid content, titratable acid content And fruit firmness decreased significantly. The contents of ethanol and acetaldehyde increased significantly in pulp tissue. The activities of major antioxidant enzymes such as peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) The content of malondialdehyde increased, the content of soluble protein decreased and the relative conductivity of cells increased significantly. The activity of polyphenol oxidase (PPO) was relatively high and the content of total phenols decreased. The respiration rate and ethylene release rate were significantly increased Higher than the green fruit. Therefore, the ’Jinchuan Sydney’ plucked the ethylene and respiration metabolism, accelerated the senescence of fruits, the accumulation of fermentative metabolites such as ethanol and acetaldehyde, reduced the activities of antioxidant enzymes and increased the level of membrane peroxidation, while PPO catalyzed the phenols Substrate oxidation, which led to ’Jinchuan Sydney’ black heart and other organizations browning occurs.