Study On Effect Of Potassium Permanganate And Calcium Hypochlorite On Peach Preservation

China is the largest producer of peaches and nectarines in the world.In order to reduce the loss of fruit due to decay and circulation process,the preservation measures of peach fruit have been addressed all the time in recent years.There are mainly three kinds of measures to keep fruits and vegetables fresh at home and abroad: chemical,physical,and biological.Low temperature preservation and preservation of fresh agent are widely used.Peach is a cold fruit,low temperature easy to cause cold damage.Potassium permanganate and calcium hypochlorite have strong oxidizing,calcium hypochlorite and KMnO4 could react with ethylene(CH2=CH2),and potassium permanganate can be generated in response to oxygen and absorbing carbon dioxide,promote the aerobic respiration of peach fruit,reduce alcohol,acetaldehyde and other oxygen-free respiration toxic products.Potassium permanganate solution with three concentrations of 0.005%,0.01% and 0.02%and calcium hypochlorite with three concentrations of 1%,2% and 4% were selected for the preservation research of ‘chunxue’ peach fruit reference the disinfection of fresh cut fruit concentration,with 75% alcohol as sterilization,found that(1)0.005%,0.01%,0.02%,three concentrations of potassium permanganate processing improved the ‘chunxue’ peach fruit solid color brightness,look and feel much better,0.02% potassium permanganate deepened peach red color surface,0.005%,0.01%,potassium permanganate concentration treatment is better.After the treatment of calcium hypochlorite,there was a white covering on the surface of peach fruit,and the higher the concentration,the more obvious the cover.(2)In the analysis of the variation of hardness and soluble solids in storage over time,0.01% potassium permanganate treatment was better than other treatments,0.01% potassium permanganate treatment was significantly higher than the control group at the level of 5% during the storage period of 1 month,and the variation of soluble solids over time was not significant compared with the control group.Fruit hardness directly reflects the storage resistance of fruit.(3)Each treatment had a strong effect on the microorganisms on the surface of peach fruit,with the fungal killing effect of 4%Ca(ClO)2 > 75% alcohol > 0.02% KMnO4 > 2%Ca(ClO)2 > 1%Ca(ClO)2 > 0.01% KMnO4 > 0.005% KMnO4.The total sterilization effect of calcium hypochlorite is better than potassium permanganate.After considering the effects of preservation and sterilization,0.01% potassium permanganate and 2% calcium hypochlorite were selected for further study.(1)After the storage for two months,the rate of intact fruit of 0.01% potassium permanganate treatment was significantly higher than that of control,whereas the rate of intact fruit of 2% calcium hypochlorite was small.The fruit was dull and dull and the skin was black in the control group,while the peach fruit in the potassium permanganate treatment was bright in color,ruddy and lustrous,which indicated that it was less affected by low temperature,and confirmed that potassium permanganate played a beneficial role in alleviating the chilling injury of ‘chunxue’ peach fruit.(2)The contents of soluble sugar in peach fruits treated with potassium permanganate and calcium hypochlorite did not change significantly,but the content of organic acids decreased significantly,and the ratio of glycolic acid increased more than two times.(3)Fruit aroma in the analysis,0.01% KMnO4 as peach fruit antistaling agent to reduce the content of ketones,alcohols and benzene Class,the kinds of KMnO4 can eliminate ethanol produced at the same time,promote the characteristic aroma gamma caprolactone,improve the cis-2-leaf alcohol acetate and positive-2-hexene production of acid butyl ester,to a certain extent,improve the flavor loss due to low temperature.After calcium hypochlorite treatment,the amount of aromatic substances in the total amount of ketones decreased significantly,and the amount of phenyl and alkanes in aromatic substances decreased significantly.(4)It was found that potassium permanganate had no significant effect on the activities of CAT and SOD,and 2% calcium hypochlorite inhibited SOD activity.The increased amplitude of POD activity in pulp of 0.01% potassium permanganate processing is relatively small,and the POD activity in the control group and calcium hypochlorite group increased rapidly at about 30 days,whereas the POD enzyme in potassium permanganate processing group began to rise quickly at about 45 days.Furthermore,the POD activity was positively correlated with the browning of peach fruit.Therefore,the potassium permanganate processing can alleviate the browning in chilling injury of peach fruit,and the effect of calcium hypochlorite is not obvious.(5)The effect of calcium hypochlorite on the preservation of peach fruit was not significant.‘chunxue’peach fruit 2.21 mg/kg,Mn element content in potassium permanganate treatment group after washed down to Mn element content was not significant at 5% level,the ‘chunxue’ peach fruit differences in Mn element content in the skin and flesh,and the content in skin was obviously higher than in flesh,up to 10 ~ 12 mg/kg,the Mn element content in peach skin of 0.01% potassium permanganate is higher after processing,but along with the increase of storage time,the content significantly reduced,and the reduction amplitude was further increased after wash.