Application Of Atomization Fumigation Combined With Modified Atmosphere Packaging Technology In Storage And Transportation Of Winter Jujube

Xinjiang Dongzao(Ziziphus jujuba Mill.cv.Dongzao)is widely welcomed by consumers because it is crisp and sweet with rich nutrition.After harvest,winter jujube will rapidly be color-changed,browning,soften and shrink,which greatly affects the quality during postharvest storage and transportation.Calcium chloride and salicylic acid,as two high-safety fruit preservative,can delay the softening and color change of winter jujube after harvest,and maintain the fruit quality.while there has been no relevant research on the combined use of two preservatives.Compared with other preservation methods,atomized fumigation is highly safe,accurate and without pollution.Modified atmosphere packaging prolongs the storage period of fruits by replacing gas components with gas barrier materials.In order to explore the effect of atomization fumigation combined with modified atmosphere packaging technology on the quality of winter jujube after harvest,the Dongzao jujube were used as the research material and treated with Ca Cl₂combined with SA.The storage and transportation quality and anti-oxidation of winter jujube during the storage period was studied.The cell wall metabolism of Dongzao jujube treated by fumigation combined with modified atmosphere packaging technology were studied.The color change and browning during storage and transportation of Dongzao jujube were also analyzed.The main findings are as follows:(1)The effects of 2%Ca Cl_2,2%Ca Cl₂+100 mmol/L SA and 2%Ca Cl₂+200 mmol/L SA atomization fumigation on winter jujube were investigated.The postharvest quality and resistance to oxidation of Dongzao were analyzed during storage on(20±1)?.All atomized fumigation treatments can maintain the quality of winter jujube.Among them,the 2%Ca Cl₂+100 mmol/L SA treatment showed the best effect.It can slow down the color-change process of winter jujube and delay the weight loss rate during storage.The decrease of hardness,titratable acid,vitamin C,total phenols,flavonoids,antioxidant of1,1-diphenyl-2-trinitrophenylhydrazine,2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing were inhibited as well.(2)The effects of atomization fumigation combined with modified atmosphere packaging technology on the postharvest quality and cell wall metabolism of Dongzao were discussed during storage and transportation.The following three treatments are used in this part:(1)control(T1):winter jujubes packed with PE film;(2)T2:the winter jujubes were put into the boxes which were filled with 8%O₂+92%N₂,then packed with PE film;(3)T3:after fumigated with atomized 2%Ca Cl₂+100 mmol/L SA,the boxes with winter jujubes were filled with 8%O₂+92%N₂,and packed with PE film.After treatment,the boxes were perforated with a hole(diameter of 0.40 mm)in the membrane and stored at(20±1)?.The T3treatment performed the best effect,which obviously inhibited the decrease of hardness,TA,protopectin,and cellulose content.The increase of decay rate,weight loss rate,cell membrane permeability,TSS,soluble pectin,cellulase,pectin methyl esterase and polygalacturonase rise were delayed.(3)The effects of atomization fumigation combined with modified atmosphere packaging technology on postharvest color change and browning of Dongzao were discussed.The processing method is the same as(2).The T3 treatment group had the best effect,which effectively delayed the color-change process and browning.The increases of contents of anthocyanins and carotenoids were retarded by T3.The enzyme activities of polyphenol oxidase,oxidase peroxidase and phenylalamine ammonia lyase were decreased.The decline of chlorophyll,total phenols,and flavonoids were also delayed by T3.