臭氧氧化对鲢肌球蛋白热聚集的影响

Effect of ozone oxidation on thermal aggregation of myosin from sliver carp (Hypophthalmichthys molitrix)

以鲢肌球蛋白为对象,测定臭氧处理后肌球蛋白在加热过程中的疏水性、浊度、粒径和分子质量分布变化,研究臭氧氧化对鲢肌球蛋白热聚集过程的影响。结果发现,肌球蛋白表面疏水性和浊度均随着加热时间的延长显著增加,随后上升趋势减缓;臭氧氧化15~60 s的肌球蛋白表面疏水性和浊度显著大于未氧化的肌球蛋白,但臭氧氧化15~60 s的肌球蛋白样品之间没有显著性差异,臭氧氧化5 min的肌球蛋白的表面疏水性显著下降。加热前30 min,随加热时间延长,大粒径的肌球蛋白聚集体相对含量逐渐增加,加热最后30 min,其含量下降。臭氧氧化的肌球蛋白粒径分布的峰值随氧化时间的增加向大粒径方向偏移。臭氧氧化加速肌球蛋白的热聚集,轻度臭氧氧化与未氧化肌球蛋白的热聚集过程相似,但轻度氧化的肌球蛋白聚集较快;而重度臭氧氧化使肌球蛋白在加热前已形成不规则聚集体,加热后使肌球蛋白迅速产生不溶性蛋白聚集体。

The myosin was prepared from silver carp.The thermal aggregation process of ozone oxidized myosin was studied using the surface hydrophobicity,turbidity,particle size and molecular weight distribution as indexes.The results showed that the surface hydrophobicity and turbidity of myosin significantly increased with the prolongation of heating time,and then the upward trend slowed down.The surface hydrophobicity and turbidity of myosin with ozone-oxidation for 15-60 s was significantly higher than those of unoxidized myosin.However,there was no significant difference between the myosin samples with ozone oxidation for 15-60 s,and the surface hydrophobicity of myosin with ozone oxidation for 5 min decreased significantly.The relative content of the large-sized myosin aggregates gradually increased with the heating time prolonged,and the content decreased after 30 min of heating time.The peak of particle size distribution of ozone oxidized myosin shifted toward the large particle size direction as the oxidation time increases.Ozone oxidation accelerated the thermal aggregation of myosin.The thermal aggregation process of mildly oxidized myosin was similar to that of unoxidized myosin,but mildly oxidized myosin aggregates faster.Severe ozone oxidation caused myosin to form irregular aggregates before heating,and rapidly produce insoluble protein aggregates after heating.