作 者：
王雷;田晓宁;田雪婷;吴晗笑;李瑞;刘佳;任小林
关键词：
‘富士’苹果;CO_2伤害;膜脂代谢;能量代谢
摘 要：
【目的】探索‘富士’苹果果实长期贮藏过程中的最适O_2/CO_2比例,为采后‘富士’苹果果实贮藏提供理论依据。【方法】以‘富士’苹果果实为材料,在(1±0.5)℃贮藏条件下,采用不同比例O_2/CO_2简易气调长期贮藏,测定不同贮藏条件下果实品质、相对电导率、丙二醛(MDA)、ATP、过氧化氢(H_2O_2)含量、超氧阴离子(O_2~-)生成速率、PLD、SOD、线粒体H~+-ATPase、线粒体Ca~(2+)-ATPase、SDH和CCO活性的指标,从膜脂代谢和能量代谢两个角度来分析不同比例O_2/CO_2简易气调过程中‘富士’果实发生CO_2伤害的原因。【结果】‘富士’苹果长期贮藏过程中,不同比例O_2/CO_2简易气调均可有效维持果实质量、硬度、可滴定酸含量、可溶性固形物含量;但当处理中O_2浓度小于10%、CO_2浓度大于5%时,果实发生CO_2伤害,果实中与能量产生相关的线粒体H~+-ATPase、线粒体Ca~(2+)-ATPase、SDH、CCO活性降低,ATP含量减小,同时SOD活性减弱,O_2~-、H_2O_2产生增加,PLD活性被激活,膜结构的完整性被破坏,褐变发生。【结论】‘富士’苹果果实长期贮藏过程中保鲜效果最好的是处理Ⅰ(3%CO_2+12%O_2+85%N_2),当O_2浓度小于10%、CO_2浓度大于5%时,细胞维持较低能量水平,膜脂过氧化严重,CO_2伤害发生。
译 名：
Effect of different O_2/CO_2 proportions on the physiological characteristics of ‘Fuji’ apple fruit during modified atmosphere storage
作 者：
WANG Lei;TIAN Xiaoning;TIAN Xueting;WU Hanxiao;LI Rui;LIU Jia;REN Xiaolin;College of Horticulture, Northwest Agriculture and Forestry University;
关键词：
‘Fuji’ apple;;CO_2 injury;;Lipid metabolism;;Energy metabolism
摘 要：
【Objective】In this test,'Fuji'apple fruit was used as the material and stored at(1±0.5) ℃ to study the effect of different ratios of O_2/CO_2 treatment on fruit quality, including firmness, titratable acid and soluble solids content, relative conductivity, MDA, ATP and H_2O_2 contents, O_2-production rate,PLD, SOD, mitochondrial H~+-ATPase, mitochondrial Ca~(2+)-ATPase, SDH, and CCO activity during modified atmosphere storage. In order to explore the causes of CO_2 damage to'Fuji'fruit with different ratios of O_2/CO_2 treatment from the perspectives of lipid and energy metabolisms, the optimum O_2/CO_2 ratio of the'Fuji'apple during modified atmosphere storage was determined, which provided a theoretical basis for'Fuji'apple storage after harvest.【Methods】'Fuji'apples were picked from the Baoji Qianyang Apple Experimental Farm of Northwest A & F University, China, on 23 October 2018. After standing at room temperature for 24 hours to dissipate the field heat, 600 healthy fruits with the same maturity and sizewithout diseases, pests and mechanical damage were selected for subsequent experiments. The fruits were then divided into four groups and 150 fruits were contained per group. The fruits of four groups were put into sealed plastic buckets with a volume of 120 L, and stored in a refrigerator at(1±0.5) ℃ and with 85%-90% relative humidity. The gas ratios of four groups included treatment Ⅰ3%CO_2+12%O_2+85%N_2; treatment Ⅱ 5%CO_2+10%O_2+85%N_2; treatment Ⅲ 10%CO_2+5%O_2+85%N_2;and CK was just common air.'Fuji'apple samples were taken out every 30 days, and 10 fruits were taken for each treatment. Relevant indexes were determined and some samples were saved for subsequent tests. The O_2/CO_2 ratio was readjusted after sampling.'Fuji'apples were stored for 150 days.【Results】During the long-term storage of'Fuji'apples, compared with ordinary refrigeration, simple air-conditioning with different ratios of O_2/CO_2 treatment can effectively maintain fruit quality, including hardness, titratable acid content, and soluble solids content. Among them, Treatment I had the best effect on delaying fruit weight loss. At the same time, the effects of the three treatments on the soluble solids and titratable acid contents were not significantly different. The CO_2 injury of'Fuji'apple was visualized as flesh browning. CK and Treatment Ⅰ fruits did not have CO_2 damage during the longterm storage. Treatment Ⅰ had no significant effect on the membrane integrity. When the O_2 concentration was less than 10% and the CO_2 concentration was more than 5% during the long-term storage, the flesh of'Fuji'apple browned worse with the decrease of the O_2/CO_2 ratio. Cell membrane lipid metabolism and energy level were the main factors that affected browning. The energy level of cells played an important role in maintaining cell membrane integrity. In this study, during the long-term storage of'Fuji'apples, Treatment Ⅰ had no significant effect on the mitochondrial H~+-ATPase and CCO activity. When the O_2 concentration was less than 10% and the CO_2 concentration was more than 5%, mitochondrial H~+-ATPase and CCO activity decreased. At the same time, with the decrease of the O_2/CO_2 ratio, mitochondrial Ca~(2+)-ATPase and SDH activity as well as the ATP content of'Fuji'apple fruit decreased. Damage to membrane integrity was considered to be one of the main causes of browning. The lipid metabolism of cells was related to PLD and SOD. In this study, during the long-term storage of'Fuji'apples, Treatment Ⅰ can maintain lower O_2-production rate, as well as H_2O_2 and MDA contents.When the O_2 concentration was less than 10% and the CO_2 concentration was more than 5%, O_2-production rate and H_2O_2 content increased. With the decrease of the O_2/CO_2 ratio, SOD activity decreased,PLD activity, relative conductivity and MDA content increased, and the flesh of'Fuji'apple browned worse.【Conclusion】In this study, the best preservation effect on'Fuji'apple fruit during modified atmosphere storage was Treatment Ⅰ(3%CO_2+12%O_2+85%N_2). During the long-term storage of'Fuji'apples, compared with ordinary refrigeration, simple air-conditioning with different ratios of O_2/CO_2 treatment can effectively maintain fruit quality, including hardness, as well as titratable acid and soluble solids contents. However, when the O_2 concentration was less than 10% and the CO_2 concentration was more than 5% during the long-term storage, the flesh of'Fuji'apple browned worse with the decrease of the O_2/CO_2 ratio. The mitochondrial H~+-ATPase, mitochondrial Ca~(2+)-ATPase, SDH and CCO activities related to energy production in the fruit decreased, resulting in decreased ATP content. Cells maintained lower energy levels. This led to a decreased SOD activity and increased production of O_2~-and H_2O_2, and PLD activity was activated. This caused the membrane integrity to be destroyed and CO_2 injury to occur.
