反复冻融对脆肉鲩鱼肉营养品质和质构特性的影响

Effect of Freeze-Thaw Cycles on Nutritional Quality and Texture Change of Ctenopharyngodon Idellus C. et V

通过测定脆肉鲩鱼片食用品质特性、全质构特性、脂肪氧化(硫代巴比妥酸值,TBARS)、挥发性盐基氮(TVB-N)以及肌原纤维蛋白羰基、总巯基含量的变化,研究了不同冻融次数(0、1、3、5、7、10)对脆肉鲩鱼肉品质特性的影响。结果表明:随着冻融次数的增加,解冻汁液损失逐渐增大,且差异显著;加压失水率和蒸煮损失率均出现先增大后降低的趋势;p H值则先降低后增大;亮度(L*)随着冻融次数的增加不断增大,红度(a*)和黄度(b*)不断减小,白度(W)不断增大;硬度和弹性随着冻融次数的增加逐渐降低;脂肪氧化程度和挥发性盐基氮含量逐渐增加;蛋白羰基含量不断增加,巯基含量不断减小;鱼肉的微观结构也发生了很大的变化,肌原纤维紧密程度和断裂程度增加,鱼肉的保水性逐渐降低。因此,随着冻融次数的增加,鱼肉品质下降。

In order to explore the effects of freeze-thaw cycles (0,1,3,5,7,and 10 cycles) on quality characteristics of Ctenopharyngodon idellus C. et V,the changes of basic eating quality,full textural properties,thiobarbituric acid-reactive substances (TBARS),total volatile base-nitrogen (TVB-N),protein carbonyl content,and total sulfhydryl content of treated samples were evaluated after repeated frozen-thawing in this paper. The results showed that with the increase of freeze-thaw cycles,thawing juice loss significantly increased (P<0.05). Cooking loss and pressure filtration rate increased firstly and then decreased,however,the pH value was just opposite;L^* value (brightness),whiteness,TBARS,TVB-N and protein carbonyl content increased gradually;a^* value,b^* value,hardness,springiness decreased gradually with freeze-thaw cycles. The microstructure of the samples had changed a lot,and the degree of tightness and fracture of myofibril increased as the number of freeze-thaw cycles increased. All the results demonstrated that freeze-thaw cycles could lower the quality of samples and this effect was positively related to the number of freeze-thaw cycles.