Study On Change Rules Of Quality And Preservation Techniques Of Bok Choy During Storage

Bok choy could easily occur water loss, yellowing and decay of suchphenomena post-harvest, leading to decline in commodity value,which is notconducive to the industrial development of the fresh leafy vegetables. So it isimminent to clarify the quality changes and browning mechanism of bok choyduring storage at room temperature in order to find an appropriate preservationtechnology.Physiological and biochemical change law of fresh bok choy after harvest wasstudied. Correlation coefficient method was used to premilinaryly investigate thebrowning mechanism of bok choy. In addition, on the basis of the browningmechanism of bok choy, some appropriate preservation measures were taken toinhibit the browning. The conclusions were summarized as follows:(1)The weight loss rate was increasing, browning degree increased, thesensory score decreased during storage. soluble sugar, Vc content graduallydeclined, chlorophyll content, carotenoid contents, respiration rate and ethyleneproduction increased. Relative conductivity and MDA content rose, while theactivity of PPO, POD and PAL as a whole increased. In addition, total phenoliccontent presented a trend of down at first and then up.(2)PPO and POD were main enzyme resulting in enzymatic browning of bokchoy during storage. Membrane lipid oxidation played a promating role in bokchoy’s browning. Vc oxidation and decomposition were the dominating reason fornon-enzymatic browning of bok choy during storage, transpiration and respirationpromoted the deterioration of quality to some extent. At the same time, chlorophylldegradation is a key reason for the browning of bok choy.(3) The effect of plant growth regulator6-BA, fungicides chlorine dioxide andcalcium chloride on keeping bok choy fresh during storage was better. Processoptimization results showed that25mg/L of6-BA,20mg/L of chlorine dioxide,1%of calcium chloride,20min of soaking time coule keep the bok choy fresh. Bokchoy without fresh-keeping process could only maintain3days,however after theoptimization process, the shelf life of bok choy could be prolonged to about5days.