| The G.frondosa fruit bodies as samples were preserved with electron beam irradiation, MAP combined with storage temperature or chemical preservatives.The changes of physio-biochemical parameters were determined,which were the rate of weight loss,sensory quality,the related enzyme activity(superoxide dismutase(SOD),catalase(CAT),protease), malonadehyde(MDA),soluble protein,total sugar and reducing sugar.Through analyzing the changes of the physio-biochemical characteristics,it was revealed the relationship between them, senescence and storage property,in order to explore the suitable storage and fresh-keeping technologies for the postharvest fruit bodies of G.frondosa cultivated in a large scale.1.The combinations of electron beam irradiation,MAP and storage temperature were designed by orthogonal test.The effects of them on the postharvest quality and fresh-keeping technology of the fruit bodies of G.frondosa no.9008 were investigated during storage,RH (70±1)%.The analysis of sensory evaluation showed that the effects of all the treatments but the combination of 1.4kGy,PVC film and 10℃were better than the control(packaged with PVC, stored at 4℃).All four treatments stored at 1℃,the combination of 1.8kGy and OPP film stored at 10℃,and the combinations of 1.4kGy and OPP film,1.8kGy and PP film,2.2kGy and OPP film stored at 4℃can extend the shelf life of the G.frondosa fruit bodies to at lest one week. The orthogonal analysis indicated that the combination of 0.8kGy,PE film and 4℃significantly (P＜0.05) exhibited very potentially in maintaining the postharvest quality fruit bodies of G. frondosa.Higher increases in anti-oxygen enzyme activity and total sugar content,lower increases in malonaldehyde accumulation and soluble protein content,and lower decreases in reducing sugar content during initial storage of fruit bodies treated with the combination of 0.8kGy,PE film and 4℃.The major factor is irradiation doses,and the miner one is packaging films,then is storage temperature(P＜0.05).When the other two factors were confirmed,the higher doses(≥1.8kGy) or storage temperature(10℃) was,the bigger changes of the physio-biochemical characteristics were,so the worse for storage.PVC films were bad for the G.frondosa fruit bodies storage.2.The G.frondosa no.151 fruit bodies as samples were coated with 0.5%(w/v) chitosan, 1.0%(w/v) chitosan,2.0%(m/v) chitosan,0.5%(w/v) CaCl2+1.0%(w/v) chitosan and 0.5% (w/v) CaCl2,respectively and untreated as the control.The purpose was to unveil the physio-biochemical characteristics of the postharvest G.frondosa fruit bodies and effective alternative in fresh-keeping technology,stored at 4℃,RH 65～70%.Treatment with 1.0% chitosan exhibited a potential for shelf life extension in maintaining the postharvest quality of the G.frondosa fruit bodies.The results showed that the samples coated with 1.0%chitosan exhibited lower increases in MDA accumulation,smaller increases in soluble protein content and reducing sugar content,and higher increases in CAT activity,respectively.Higher increases in SOD activity and lower decline in weight loss exhibited in samples coated with 1.0%and 2.0%chitosan.Lower increases in protease activity showed in samples coated with 2.0% chitosan.Higher levels in total sugar content exhibited in samples coated with 0.5%CaCl2 The fresh-keeping effects of the mixture of 0.5%CaCl2 and 1.0%chitosan were worse than 1.0% chitosan only.Compared to the control,the treatments with chemical preservatives had higher increases in anti-oxygen enzyme activity,and lower increases in protease activity,which were good for storage and delaying senescence.Polysaccharides are the main ingredient for pharmacological activity in the G.frondosa fruit bodies,the amount of content of which has an effect on the commodity value directly. Although higher levels in polysaccharides content treated with 0.5%CaCl2,it was not beneficial to the other parameters,so it was bad for storage. |
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