Study On Ethylene Ripening Technology In Postharvest Kiwifruits Of ’Cuixiang’ And ’Hwyward’

Kiwifruit needs post-harvest diet to achieve the state of consumption,natural long after-ripening time,inconvenience to consumers.In order to allow the instant kiwifruit to reach the instant fruit,our group previously studied the post-harvest artificial ripening methods of two kiwifruit varieties,’Huayou’ and ’Xuxiang’.However,different kiwifruit varieties have different sensitivities to ripening active substances.In this experiment,the kiwifruit ’ Cuixiang’ and ’Hayward’ were tested at room temperature with 50 μL/L、 100 μL/L、150 μL/L and 200 μL/L ethylene under different hardness conditions,and the related physiological changes and quality indicators were determined,including fruit hardness,soluble solid,soluble total sugar,titratable acid,starch,Vc content,color,respiration rate and weight loss rate,and sensory evaluation of the fruit under different hardness conditions after treatment.The aim was to study the effect of ethylene treatment on the fruit quality of the two kiwifruit varieties,and to explore the optimal ethylene ripening concentration and optimum edible hardness of ’Cuixiang’ and ’Hayward’ fruits.The results are as follows:1.Treatments with 50 μL/L、100 μL/L、150 μL/L and 200 μL/L ethylene accelerated the decrease of fruit firmness of kiwifruit,reduced the weight loss rate of the fruit before it reached an edible state,and promoted starch degradation.Soluble total sugar content the time of maximum appearance is advanced,and the decrease of titratable acid content is accelerated,and the ratio of sugar to acid is increased,which accelerates the fruit ripening and softening.2.The sensitivity of ’Cuixiang’ and ’Hayward’ to ethylene is different.The early-maturing variety ’Cuixiang’ is more sensitive to ethylene and can achieve better results after 50 μL/L ethylene ripening.The late-maturing variety ’Hayward’ is less sensitive to ethylene than’Cuixiang’,the best ethylene concentration under ripening performance is different,the fruit hardness ≥ 5.5 kg/cm~2 is suitable for 100 μL/L,and ≤ 5.5 kg/cm~2 is suitable for 50 μL/L.3.The hardness of ’Cuixiang’ fruit on the day of harvest was 9.97 kg/cm~2.After the optimum ripening concentration of 50 μL/L,it reached the edible hardness on the 3d,and reached the best edible hardness on the 5th day.The harvesting time of ’ Hayward ’ was the same.The hardness was 12.09 kg/cm~2.After the optimum ripening concentration of 100 μL/L,the edible hardness range was reached on the 7th day,and the best edible hardness range on the 9th day.When the firmness was chilled to 8.22 kg/cm~2,after being treated with 100 μL/L ethylene,the edible hardness was reached on the 5th day and the optimal hardness was reached on the 7th day.When the fruit hardness was reduced to 5.54 kg/cm~2,the optimal ripening ethylene concentration was 50 μL/L,and it was edible on the 4th day,the best use of the hardness of the 6th day;Refrigerated the hardness to 3.83 kg/cm~2,after the concentration of 50 μL/L ethylene treatment reached the edible hardness on the 3th day,and 4th day reached the best edible hardness range.4.The final sensory evaluation results showed that the edible hardness of ’Cuixiang’ and’Hayward’ were 1.5-1.8 kg/cm~2 and 1.2-1.5 kg/cm~2,respectively;the most suitable edible hardness of both varieties was 0.8-1.0 kg/cm~2.