| The study was to investigate the effect of different doses of UV-C treatment(0,2,3,4 k J/m2)on weight loss、total sugar content、MDA content、antioxidant contents and quality of postharvest Pleurotus eryngii during storage at 2°C for 35 days.Results of the study provide the references to further extend the shelf life of processed Pleurotus eryngii.The main research contents and results:When measured weight loss rate using the gravimetric method,measured by weight loss rate of Pleurotus eryngii on the various storage time is overall upward trend,weight loss rate of CK group in each period were higher than UV-C irradiation,in the 35 d,weight loss rate of CK group were higher than UV-C irradiation group nearly doubled,and the weight loss rate between the UV-C treated group was not significantly different,UV-C treatment inhibited the Pleurotus eryngii of water loss and respiration.The color changes was measured by color difference meter,observing the changes in L *,a * and b * values found no significant difference between the groups,after the first 14 days,with the increasing maturity of Pleurotus eryngii caused a slight browning.Meanwhile,UV-C treatment did not adversely affect the color change of Pleurotus eryngii.When measuring respiration,the study found 4 k J/m2 irradiation make a sharp rise in respiration rate,caused the body damaged by excessive radiation intensity.When pH was measured,p H value showed the trend of the first rise and then decrease,3k J/m2 irradiation is due to the effective sterilization while maintaining relatively intact mushroom tissue,p H changes was smallest.p H value variation of 2k J/m2 and 4 k J/m2 treatment was large,there was a clear peak.When UV-C irradiation intensity was too large or too low,microbial growth and activity of the inhibitory effect was not obvious.In determining the total sugar content,the results show,3k J/m2 treated was more effectively maintaining the total sugar content,it had been maintained mushroom storage quality.4k J/m2 treatment group was due to the large radiation intensity caused surface damage,lead to enhance respiration,carbohydrate content increased in the first 7 days.In the determination of the total soluble solids,in the storage 35 d,total soluble solids of UV-C treatment group compared with the initial contents was a slight increase.Total soluble solids content of UV-C treatment was significantly(P <0.05)higher than CK group.When Thiobarbituric acid method used the determination of MDA,on the entire storage process,MDA levels was rise in 7d later,the rate of increase was significantly higher than CK treatment group,treatment group can inhibit MDA increased speed.When on the 21 d,MDA levels of 2,3,4 k J/m2 treatment group was only 67.34%,61.62%,51.64% of the CK group,treatment groups was not significant difference.Experiment showed UV-C treatment can inhibit lipid of per-oxidation,reduce MDA accumulation during storage,ease estimate the extent of browning.When measured the total phenolic,total phenolic of content UV-C treatment group(P<0.05)was higher than CK group between UV-C treatment group,the total phenolic content did not change significantly during storage.When using DPPH measured antioxidant capacity,4k J/m2 treatment group of mushroom had some mechanical damage during storage,antioxidant had big variations.After post storage,it had a strong antioxidant.While 2 k J/m2 treatment group had a significant difference in oxide activity(P> 0.05)with CK group;3 k J/m2 treatment group was due to appropriate irradiation intensity stimulation beneficial response mushroom body,its antioxidant activity was higher than CK group.Suitable UV-C irradiation intensity can increase the antioxidant capacity of postharvest mushroom.When measured the total reducing power,total reducing power of UV-C treatment group was not significant difference between ck groups(P> 0.05).On the 7d,reducing power of treatment group was the first rise and then fall,followed by storage time,reducing power was stabilized and had a little higher than CK group. |
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