微冻对蚕豆籽粒保鲜效果及成熟衰老的影响

Effect of Superchilling on Preservation,Ripening and Senescence of Broad Bean Seeds

探究微冻技术对新鲜蚕豆籽粒的保鲜效果。通过测定蚕豆籽粒的冰点,确定3个微冻温度,以冷藏(4℃)为对照组,分析不同微冻温度(-2、-3、-4℃)贮藏对蚕豆籽粒感官品质、叶绿素含量、色差值等品质指标的影响,再通过多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)、苯丙氨酸解氨酶(phenylalamine ammonia lyase,PAL)活性、总酚含量、可溶性蛋白含量及细胞组织结构等研究微冻贮藏对蚕豆籽粒成熟衰老的影响。结果表明,4℃冷藏条件下蚕豆籽粒保鲜期为7 d,3个微冻温度贮藏均能显著提高样品的感官品质,其中-3℃使蚕豆籽粒保鲜期达35 d,能显著减缓叶绿素含量的降低和质量损失率、色差值的升高,能较好地维持蚕豆籽粒的硬度,采用主成分分析也得出-3℃为最佳微冻温度。-3℃微冻贮藏能减缓PPO、PAL活性升高,维持较高的POD活性,延缓蚕豆籽粒中淀粉和可溶性蛋白的生成、总酚的积累及变化速率,还能维持细胞组织结构、形态的相对稳定,减缓蚕豆籽粒的成熟衰老。

This study sought to investigate the effect of superchilling on the preservation of fresh broad bean seeds.Three superchilling temperatures(-2,-3 and-4℃)were determined based on the freezing point of broad bean seeds.The effects of superchilling storage at each temperature on the sensory quality,chlorophyll content,color difference values and other quality indexes of broad bean seeds were analyzed using chilled storage(4℃)as a control,and then the effects of superchilling storage on the ripening and senescence of broad bean seeds were studied by determining the activities of polyphenol oxidase(PPO),peroxidase(POD)and phenylalamine ammonia lyase(PAL),total phenol content,soluble protein content and the cell structure.The results showed that the shelf life of broad bean seeds stored at 4℃was 7 d,and all three superchilling temperatures significantly improved the sensory quality of the samples.Superchilling at-3℃kept broad bean seeds fresh for up to 35 d,significantly slowing down the decrease in chlorophyll content and the increase in mass loss rate and color difference values during storage and maintaining the hardness well.Principal component analysis(PCA)showed that the optimal superchilling temperature was-3℃.Superchilling storage at-3℃slowed down the elevation of PPO and PAL activities,maintained a higher POD activity,and delayed the generation of starch and soluble protein as well as the accumulation and the rate of change of total phenol content in broad bean seeds.Moreover,it maintained the relative stability of the cell structure and morphology and delayed the ripening and senescence of broad bean seeds.