Effect Of Chitosan Treatments On Fresh-cut Characteristic On Major Cultivars Of Muskmelon And Its Comparison

Fresh-cut is the main form of consumption of muskmelon.However,due to the large varieties of muskmelon,it is necessary to compare the fresh-cut characteristics of different types of muskmelon.In this paper,three cultivars of Honey dew melons?Yindi,Yinguan and Huanghemi?and Hami melons?Xizhoumi,Zidingmi and Jiashi?were employed as materials.Melon were peeled,cored and cut into pieces.The pieces were treated with chitosan at 2%,packed in polypropylene boxes and stored at low temperature.Determined the changes of quality and microbial growth during storage.and select out which different types ofmuskmelon is suitable for fresh-cut processing,and the antioxidant capacity of suitable cultivars were analyzed.The results showed that:1.Chitosan treatment effectively reduced the weight loss rate,kept the hardness,the TSS and TA content of fresh-cut melons.Maintained the color and sensory quality preferably.The Honey dew melon“Huanghemi”has the smallest change in weight loss,the hardness and TSS content.The evaluation of color and flavor of“Huanghemi”was the highest.The Hami melon“Xizhoumi”has the smallest weight loss rate and hardness change,and the evaluation of color and flavor was the highest.2.Chitosan treatment significantly inhibited the growth of the total number of colonies,mold,yeast and coliform on the surface of melon chips,and the number of these microbes increased after storage of 6d.The chitosan treatments group were significantly lower than the control group?p<0.05?.There was no significant difference in microbial growth amongdifferent melon cultivars.At the end of storage,the number of these microbes did not exceed10⁶CFU/g.Salmonella,Staphylococcus aureus and Listeria monocytogenes were not detected in fresh-cut melon during storage.3.The content of Vc,chlorophyll and beta carotene of“Huanghemi”and“Xizhoumi”were all decreased.The content of total phenols and flavonoids are upward trend and the content of V_E and GSH changed little.During storage,the V_C content of“Huanghemi”was always higher than that of“Xizhoumi”,and the total phenols,flavonoids and V_E contents of“Xizhoumi”were always higher than that of“Huanghemi”.Chitosan treatment maintained different levels of antioxidants in two cultivars of melon,and maintained the most significant effect on Vc and beta carotene content.The activities of SOD,CAT,POD,PPO and GR oftwo cultivars of fresh-cut melon increased first and then decreased during storage.The APX activity of“Huanghemi”and“Xizhoumi”showed an upward trend.There was no significant difference in the activities of antioxidant enzymes between the two cultivars.Chitosantreatment significantly inhibited the activity of APX of two melon cultivars,but had no obvious effect on other antioxidant enzyme activities.4.Chitosan could enhance the antioxidant capacity of two cultivars significantly.In the evaluation of antioxidant capacity of two cultivars of melon in vitro,the scavenging ability of"Huanghemi"melon on DPPH.free radical and ABTS.⁺radical is lower than that of "Xizhoumi".The scavenging ability of·OH and·O₂^-radicals is higher than that of "Xizhoumi",and the scavenging ability of H₂O₂ and hydrogen peroxide clearance ability are similar.In conclusion,chitosan treatment can effectively improve the quality and sensuality of fresh cut melon,and inhibited the growth of microorganisms and the emergence of pathogenic bacteria.“Huanghemi”is the most suitable for fresh-cut processing in the type of Honey dew melon.In Hami melon type,“Xizhoumi”is the most suitable for fresh-cut processing.The antioxidant content of the two caltivars after chitosan treatment is better,effectively improving the antioxidant capacity of the melon.