短波紫外线照射对白玉菇采后贮藏品质的影响

Effect of UV-C Irradiation on Postharvest Quality of White Hypsizygus marmoreus

以白玉菇为试材,贮藏于4℃条件下,分别采用0(对照组CK)、0.5、1.0、2.0 kJ/m^2剂量的UVC进行照射,定期测定白玉菇颜色、多酚氧化酶(PPO)活性、总酚含量及DPPH自由基(DPPH·)清除率等指标,探讨短波紫外线(UV-C)照射对白玉菇采后贮藏品质的影响,为UV-C技术应用于白玉菇保鲜提供理论依据。结果表明,0.5、1.0 kJ/m^2的UV-C处理可有效保持白玉菇白度、促进总酚的合成和积累,提高抗氧化物活性并抑制PPO活性的升高。其中1.0 kJ/m^2处理组白玉菇的DPPH·清除率和总酚含量显著高于0.5 kJ/m^2UV-C处理组和CK组(P<0.05),而经2.0 kJ/m^2 UV-C照射后白玉菇的L*值、DPPH·清除率和总酚含量均出现明显下降。贮藏21 d后,1.0 kJ/m^2UV-C处理组白玉菇感官品质显著高于CK组(P<0.05),贮藏期延长7 d以上。适宜剂量UV-C处理可提高采后白玉菇保鲜效果,但照射剂量过大会对白玉菇造成损伤,1.0 kJ/m^2UV-C处理的综合保鲜效果较好。

Influences of shortwave uhraviolet-C （UV-C） on storage quality of white Hypsizygus marmoreus were studied for providing scientific basis of UV-C application in fresh-keeping of white Hypsizygus marmoreus. White Hypsizygus marmoreus stored at 4 ℃ was irradiated with the radiation dose of 0, 0.5, 1.0 and 2.0 kJ/m2, respectively. Color, activity of polyphenol oxidase （PPO）, total phenol content and DPPH free radicals （DPPH.） scavenging rate were measured periodically during storage. The results indicated that 0.5 and 1.0 kJ/m2 doses of UV-C treatments could effectively maintain the whiteness, promote the synthesis and accumulation of total phenol, enhance the an- tioxidant activity and inhibit the increase of PPO activity. DPPH- scavening rate and total phenol content of the mushrooms in 1.0 kJ/m2 UV-C treatment group were significantly higher than those in 0.5 kJ/m2 and CK groups （P〈 0.05）. However, L＊ value, DPPH. scavenging rate and total phenol content of white Hypsizygus marmoreus treated by 2.0 kJ/m2 UV-C obviously reduced. After 21 days of storage, sensory quality of white Hypsizygus marmoreus treated by 1.0 kJ/m2 UV-C was significantly higher than that of the control （P〈0.05）, the storage period was pro- longed for more than 7 days. In conclusion, the suitable dose of UV-C treatment could maintain storage quality of white Hypsizygus marmoreus, while too high dose of irradiation would cause damage. 1.0 kJ/m2 dose of UV-C treat- ment had the best preservation effect.