Effects Of EA,EB And Temperature Treatments On The Quality Of Kiwifruit After Ripening

Kiwifruit is rich in vitamin C and mineral elements and loved by consumers,but it takes a long time to reach edible firmness for most kiwifruit after harvest.Recently,the research on postharvest kiwifruit mainly focuses on preservation technology,and there is still little research on ripening and quality controlling technology.Ethyl acetate(EA)and ethyl butyrate(EB)are the main volatile esters contained in kiwifruit,and their content increases with the maturity of kiwifruit.At present,there is no report about their effects on the quality of kiwifruit after harvest.Temperature is also an important factor affecting the ripening quality of fruits.Appropriate heating treatment will promote the changes of lysate and enzyme activity in the fruit,thereby promoting it’s ripening process.In this experiment,the ’Xuxiang’ and ’Hayward’ kiwifruit were used to study the effects of different concentrations of EA,EB and temperature treatment on the ripening quality of kiwifruit,and provide theoretical basis and technical support for their post-harvest quality control.The main results are as follows:(1)Control,10,50,100μL/L EA and 20,50,100μL/L EB were used to treat the’Xuxiang’ kiwifruit.The results showed that EA and EB treatments accelerated the softening process of the fruit and has a certain effect on the quality control,the firmness of kiwifruit treated with 10μL/L EA and 100μL/L EB decreased the fastest,which accelerated the conversion of fruit pectin to WSP;10μL/L EA and 100μL/L EB increased the permeability of the cell membrane and the MDA content,and accelerated the softening process;(2)The results of enzyme activity of ’Xuxiang’ kiwifruit treated with different concentrations of EA and EB during storage showed that the treatments with various concentrations of EA and EB increased PE activity;10μL/L EA and 50,100μL/L EB treatments increased β-Gal activity;10,50μL/L EA and 50,100μL/L EB increased the amylase activity and accelerated the degradation of starch;50μL/L EA treatment increased the SSC of kiwifruit and the flavor was better;(3)’Hayward’ kiwifruit wrer treated with 10°C,20°C,and 40°C treatment for 12 h and then stored at 20°C(40°C+20°C).The results showed that suitable temperature treatment accelerated the softening process of the kiwifruit.The 40°C+20°C treatment accelerated the decrease of fruit firmness,TA and starch content,and accelerated the WSP production;the storage treatment at 20°C accelerated the degradation of the pectin;the SSC of the fruit stored at 10°C was the highest;the respiration intensity and ethylene release rate of the’Hayward’ kiwifruit stored at 20°C were significantly higher than those of the other temperature treatments,followed by 40℃+20℃ treatment;(4)The softening enzyme activity of ’Hayward’ kiwifruit during storage at different temperatures showed that the 20°C treatment increased the peaks of PG,β-Gal andα-amylase activity,and accelerated the softening of the fruit;The PE activity peak value of40℃+20℃ treatment was significantly higher than those of other treatments;In summary,EA and EB treatments at various concentrations during storage stimulated the decrease in firmness and starch content of ’Xuxiang’ kiwifruit,promoted the conversion of fruit pectin to WSP,increased the softening enzymes activities,and accelerated the softening process of the fruit.The 10μL/L EA and 100μL/L EB treatments revealed the most significant effects,but 50μL/L EA treatment had a better taste;appropriate temperature treatment could also accelerate the softening of ’Hayward’ kiwifruit,of which 40℃+20℃treatment had the most softening effect and the best quality of kiwifruit were found at 10°C treatment.