以刀额新对虾为材料，研究还原型谷胱甘肽（GSH）对多酚氧化酶（PPO）的抑制作用，发现当GSH浓度为4 g/L，处理时间为30 min时对PPO的抑制效果最好。采用PPO活力、挥发性盐基氮（TVB-N）含量、白度值、肌肉盐溶性蛋白质含量、感官评价作为指标，研究在-18 ℃冻藏条件下各种GSH复配保鲜剂对刀额新对虾品质的影响。经实验证明，4 g/L GSH能有效抑制虾头PPO活力以及减缓褐变。4 g/L GSH+10 g/L山梨醇以及4 g/L GSH+5 g/L柠檬酸复配的保鲜剂能降低冻藏期间TVB-N的产生以及减缓蛋白质的降解速度，4 g/L GSH+10 g/L山梨醇+5 g/L柠檬酸复配的保鲜剂处理的虾样品有最高的感官评分。综合各指标看，由4g/L GSH+10 g/L山梨醇+5 g/L柠檬酸组成的保鲜剂具有最佳的保鲜效果。

Metapenaeus ensis was used as the material to study the inhibitory effect of reduced glutathione (GSH) on polyphenol oxidase (PPO) activity, with optimal inhibitory effect on PPO activity determined at a GSH concentration of 4 g/L and a treatment time of 30 min. PPO activity, total volatile basic nitrogen (TVB-N) content, whiteness, salt-soluble muscle protein, and sensory evaluation were used as indicators to study the effect of different reduced GSH-composite preservatives on the quality of M. ensis during frozen storage at -18 ℃. Our results showed that 4 g/L GSH effectively inhibited PPO activity and decreased melanin accumulation. The preservatives prepared from 4 g/L GSH+10 g/L sorbitol and 4 g/L GSH+5 g/L citric acid reduced the generation of TVB-N and decreased the degradation rate of salt-soluble protein during storage. Shrimp treated with the preservative composed of 4 g/L GSH+10 g/L sorbitol+5 g/L citric acid possessed the highest sensory evaluation score. These findings suggested that the preservative composed of 4 g/L GSH+10 g/L sorbitol+5 g/L citric acid exhibited the best fresh-keeping effect for the storage of M. ensis.

广州市科技计划-科技惠民专项（2014Y200107）