Effects Of Ozone Treatment And Modified Atmosphere Packaging On Postharvest Storage Quality And Physiological Metabolism Of Blueberries

Blueberries are popular among consumers because they are delicious and nutritious.In addition,blueberries are rich in antioxidants and have health benefit.Blueberries mature in hot and rainy summer,therefore,they are susceptible to mechanical injury and microbial infection.Blueberries are perishable at room temperature,resulting in loss of food value,causing significant economic losses to the industry.This study investigated the effects of ozone treatment and controlled atmosphere packaging on storage quality and physiological metabolism and enzyme activity in blueberries.The findings from this study will provide theoretical basis and practical application for postharvest blueberries preservation technology.The results showed:?1?The effects of different ozone concentrations on the storage quality and antioxidant enzyme activities of blueberries.Using different ozone concentration?1,2,3,4 ppm?,with untreated control?CK?,the results showed that ozone treatment could maintain fruit quality,firmness,color,TSS,TA,pH,Vc and anthocyanin content of blueberries fruit;delayed peak total phenolics;maintain antioxidant enzymes SOD,CAT,APX and GSH activities;the content of O₂.^-,H₂O₂ and delay the increase of MDA in fruit,fruit can maintain cell membrane function better;delayed PPO and POD decreased,PAL peak value of delay.The results also showed that too low or too high ozone concentrations were not suitable for fruit storage.The best result was obtained with the 2ppm treatment group.?2?Effects of controlled atmosphere packaging on storage quality and antioxidant enzyme activities of blueberries.Controlled atmospheres of 5%O₂+20%CO₂,5%O₂+15%CO₂,10%O₂+10%CO₂ and untreated?CK?were used.Among them,5%O₂+15%CO₂ group was the best to maintain a good fruit rate,a high peel and pulp firmness,delay TSS,TA,pH,Vc and anthocyanin content decreased,effectively delay the total phenol.The results also showed that controlled atmosphere could maintain high antioxidant enzymes SOD,CAT and APX and effectively retard the peak of SOD and CAT.The modified atmosphere effectively inhibited the contents of H₂O₂,O₂.^-and MDA,and delayed the contents of PAL and POD Peak arrival,and to maintain a higher PPO activity.The results showed that 5%O₂+15%CO₂>5%O₂+20%CO₂>10%O₂+10%CO_2.The best result was obtained in the low temperature storage environment with 5%O₂+15%CO_2.?3?Effects of ozone combined with controlled atmosphere packaging on storage quality and antioxidant enzyme activities of blueberries.Treatment with 2 ppm ozone with 5%O₂+15%CO₂ packaging at 0?storage for 50 days,could slow down the blueberry fruit rate decline,and keep better blueberry quality.This treatment also delayed the decreases of TSS,TA,pH,Vc and anthocyanins and delayed the peak of total phenol,SOD and PAL,and delayed the decrease of APX activity and retarded the increase of of H₂O₂ and MDA content.?4?Ozone combined with controlled atmosphere packaging at 20?shelf life of10 days.This treatment could effectively delay the decline in fruit quality of blueberry fruit and could retard the decrease of fruit pulp and peel firmness,delay the decline of TSS,TA,pH,and the content of anthocyanin.This treatment could also slow down the decrease of activity of antioxidant enzymes SOD and APX and PAL,and delayed the increase of H₂O₂ and MDA.