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。
Surimi from silver carp were oxidized in a hydroxyl radical generating systems (the concentration of H2O2 were 0.1,1.0,5.0,10.0 and 50.0 mmol/L,respectively),and the effects of oxidization on gel properties of surimi were investigated. The results showed that the breaking force,penetration distance,gel strength and water holding capacity of surimi gels increased firstly and decreased afterwards with the increase of H2O2 concentration. The maximum values were obtained at the H2O2 concentration of 1.0 mmol/L,indicating that moderate oxidation could improve the gel properties and the water holding capacity. At the same time,the T22 peak area in the moisture distribution also reached a maximum at the H2O2 concentration of 1.0 mmol/L. In addition,the activity of Ca2+ ATPase significantly increased and followed by a decrease with the increase of H2O2 concentration. And the SEM result showed that moderate oxidation (0.1~1.0 mmol/L H2O2) could improve surimi gel network structure,whereas excessive oxidation would lead to the destruction of the network structure