海藻酸钠复合膜对带壳鲜莲贮藏品质的影响

Effect of sodium alginate composite film on preservation of shelled seed of Xiang lotus

以带壳鲜莲为研究对象,于4℃贮藏条件下,以可溶性固形物含量(SSC)、净光合速率、多酚氧化酶(PPO)活力、过氧化物酶(POD)活力、莲壳色差及感官质量变化为评价指标,研究柠檬酸、EDTA-Na2及海藻酸钠不同配比复合膜对带壳鲜莲的护色保鲜效果,采用正交设计筛选保鲜效果较佳的保鲜剂配方。结果表明:复合膜的优化配方为柠檬酸0.3%,EDTA-Na20.015%,海藻酸钠2.5%。经该复合涂膜剂处理后,带壳鲜莲的贮藏品质明显提高,鲜莲净光合速率显著降低(P<0.01),SSC和色泽(L*、a*、b*)变化显著减缓(P<0.01),W值变化不显著(P>0.05),PPO酶活性显著受抑(P<0.01),POD酶活性受抑不显著(P>0.05),但对这两种酶类的活力高峰有一定延迟作用,从而提升带壳鲜莲的贮藏品质,延长其货架期。

The effect of different composite films（citric acid,EDTANa2 and alginate）on preservation of fresh lotus was studied.Soluble solids content（SSC）,net photosynthetic rate,polyphenol oxidase（PPO）and peroxidase（POD）activities of fresh lotus seeds and color variation of fresh lotus shell were investigated at the storage temperature of 4 ℃.Preservative formula with better preservation effect was selected through orthogonal design.The results showed that the best formula of the composite film was composed of 0.3% of citric acid,0.015% of EDTA-Na2 and 2.5% of alginate,which improved the quality of fresh lotus significantly.The composite film had extremely significant effects on SSC,L＊,a＊and b＊value,PPO activities and sensory quality of fresh lotus（P0.01）,and inhibited the net photosynthetic rate of fresh lotus significantly（P0.01）,but no significant effect on the W and peroxidase（POD）of fresh lotus（P0.05）.These results indicated that the best sodium alginate-based composite film can maintain the storage quality at the maximum extent,and prolong the shelf life of fresh lotus seed.