Observation And Study On CO₂ Damage Characteristics Of Apple Fruit During Storage

In the process of regulating the storage of apple fruit,the adjustment of oxygen and CO₂ volume fraction is particularly important.If improper operation occurs,carbon dioxide damage will occur,which will seriously damage the quality of the fruit and cause serious economic losses.At present,there are few studies on the carbon dioxide damage about apple fruit,but no research on the damage situation of specific varieties.In this study,the fruits of‘Gala',‘Honeycrisp',‘Granny Smith'and‘Fuji'were used to analyze the degree of carbon dioxide damage in different gas environment and the changes of physiological characteristics,to determine the critical concentration of carbon dioxide damage in different varieties of apple fruit,and the critical time of carbon dioxide damage in apple fruit in different carbon dioxide concentration storage environment,to explore the mechanism of CO₂ damage providing a theoretical basis for apple storage.The re6sults of the study are as follows:?1?The CO₂ damage of‘Gala'occurred in the 2%,4%,6%,8%and 10%concentration of CO₂ at 120d,and the CO₂ concentration of‘Fuji'was 5%and 7%.The critical time for injury in the 7%and 5%CO2 environment are 60d and 90d respectively.The phenomenon of CO₂ damage in‘Gala'was a brown spot on the peel and spread from the bottom of the fruit?the end of the fruit?to the top of the fruit?the end of the fruit stem?,while the heart and the flesh did not turn brown.The phenomenon of CO₂ damage in‘Fuji'is browning in the pulp near the core,and then spreads around,and the skin does not brown.With the 3%,5%and 7%CO₂ treatments,‘Honey crispy'didn't occur CO₂ damage.‘Granny Smith'suffered from tiger skin disease in 2%,4%and 6%CO₂ treatments,so we can't determine whether CO₂ damage has occurred.?2?When different varieties of apple fruit have CO₂ damage,the TA content of the fruit is kept at a high level.Their physiological indicators change.The more serious the‘Gala'CO₂ damage occurs,the higher the brightness,and the CO₂ damage has no significant effect on the brightness of‘Fuji'skin,the‘Gala'has no significant change in color saturation when CO₂ damage occurs,without CO₂ treatment,the color saturation of‘Fuji'is significantly higher than treatment group,the hardness of‘Gala'without CO₂damage is significantly higher than that of apple fruit with CO₂ damage.The more serious the CO₂ damage occurs,the lower the hardness of the fruit and the CO₂ damage.‘Fuji'hardness is higher than that of non-CO₂ damage;‘Gala'has the highest concentration of soluble solids in CO₂,while'Fuji'has no significant difference in soluble solids content;‘Gala'and in the‘Fuji'fruit,after the occurrence of CO₂ damage,the TA content of the high-concentration CO₂ treatment group was higher.The weight loss rate of‘Gala'was low,while the weight loss of‘Fuji'with CO₂ damage was not significantly different from the control group.?3?The respiratory peak of the high-concentration CO₂ treatment group of‘Gala'appeared before the low-concentration CO₂ treatment group,‘Fuji'fruit with CO₂ damage has a lower respiratory intensity;the ethylene release rate of‘Gala'becomes higher when the damage is more serious,while the‘Fuji'fruit has a lower ethylene release rate or without ethylene release peak when the damage is mild.