Effects Of Pre-harvest And Post-harvest EVA And CTS Coating On Mango Fruit Preservation

Mango is one of the famous tropical fruits.It is popular with rich flavor,good flavor and rich nutrition.However,mango ripens in high temperature and high humidity season,and its postharvest respiration is vigorous.The infection of diseases and pests before or after harvest accelerates its decay and deterioration,and shortens its shelf life.Therefore,it is particularly important to research and develop the technology which can not only reduce the use of pesticides,but also improve the quality and safety of fruit and the effect of preservation.In order to study the changes of physiological and biochemical indexes and fruit quality during storage.Meanwhile,the expression of key genes related to ethylene biosynthesis and ethylene receptor were detected by Q-PCR.‘Guire No.82' mango were treated with polyethylene vinyl acetate chitosan(EVA)and 1% chitosan coating(CTS)respectively before harvest 30 days,‘Tainong No.1' mango were treated with EVA and CTS respectively after harvest.The results showed that:1.Compared with water treatment,pre-harvest and post-harvest treatments with EVA and CTS coating could significantly reduce the decay rate,weight loss rate and hardness of mango,the change of total color difference(?E)was restrained,and the effect of EVA treatments was better than CTS treatments.Pre-harvest and post-harvest treatments with EVA and CTS coating could significantly delayed the decline of chlorophyll content,inhibited the increase of Carotenoid and anthocyanin content.Compared with CTS treatments,EVA treatments could significantly inhibited the accumulation of Carotenoid and anthocyanin content;Post-harvest treatments with EVA treatments could significantly delayed the decline of chlorophyll.Both EVA and CTS treatment could significantly delayed the change of soluble solids and soluble sugar content,and delayed the decline of titratable acid content,the inhibitory effect of EVA treatment on mango acid transformation was more significant than CTS treatment.2.Compared with CK treated with water,pre-harvest and post-harvest EVA,CTS coating treatment could significantly inhibited the increase of malondialdehyde(MDA)and relative conductivity,delayed the decrease of oxidized glutathione(GSSG),increased the contents of glutathione(GSH),ascorbic acid(As A),and ascorbic acid peroxidase(APX),glutathione reductase(GR)activity.Moreover,the effects of EVA trenments on MDA,GSSG,GSH,As A and GR were better than CTS trentments.3.Compared with CK treated with water,pre-harvest and post-harvest treatments with EVA and CTS coating could significantly delayed the decrease of polyphenol content,inhibited Polyphenol oxidase(PPO)activity,ascorbic superoxide dismutase(SOD)and catalase(CAT)activity.moreover,the activities of SOD and CAT in mango treated with EVA trentments were significantly higher than that CTS trentments.EVA treatment was significantly increased peroxidase(POD)activity and flavonoids content.CTS treatment had no significant effect on flavonoids,but CTS treatment was significantly reduced POD activity of ‘Tainong No.1'.Pre-harvest EVA treatment was more significant than CTS treatment on delaying the decrease of polyphenols content in ‘Guire No.82',but they were not significant in ‘Tainong No.1'.4.Compared with CK which treated with water,post-havest EVA and CTS coating could inhibiting Ethylene release,decreased ACS and ACO activity,inhibiting ethylene receptor ETR1,ETR2 and ERS1 expression in ‘Tainong No.1'.EVA and CTS trentments had no significant difference in reducing ethylene release.Compared with CTS trentment,EVA trentment could more significantly inhibit ACO,ACS,ETR1,ETR2 and ERS1 expression in mango.5.Pearson correlation analysis showed that the decay rates of CK,EVA and CTS treatments were significantly or extremely significantly correlated with the weight loss rate,the content of Carotenoid and malondialdehyde,and significantly or significantly negatively correlated with chlorophyll and hardness.The decay rates of CK,EVA and CTS treatments were significantly or extremely significantly correlated with the weight loss rate,the content of Carotenoid,the content of malondialdehyde,the content of SSC,the activity of CAT,the ethylene release and the relative expression of ETR1,extremely significant or significant negative correlation with chlorophyll.