Effects of Freezing-thawing on Mutton Quality, Nutrition Components and Ultrastructure of Lanzhou Fat-tailed Sheep
In order to study the effects of freezing-thawing on mutton quality,nutrition components and ultrastructures,longissimus dorsi were collected from 1.0-1.5 year-old Lanzhou Fattailed sheep,vacuum packed and repetitively frozen-thawed for different times,and then meat qualities,nutrition components and ultrastructures were studied.The results showed that,compared with fresh mutton,the thawing loss (TL),cooking loss (CL),dry matter (DM) content and ash content were significantly increased (P＜0.05) while the shear force (SF) and crude protein (CP) content were significantly decreased (P＜0.05) with the increase of times of freezing-thawing.Water loss (WL) and crude fat (CF) were significantly increased after frozing-thawing for two and three times (P＜0.05),respectively.Freezing-thawing had no significant effect on pH (P＞0.05).In the same time,freezing-thawing vacuolated structure formation in the mitochondria,confused fiber bundles,increased the space between muscle fiber,and shortened sarcomere,blurred even disappeared Z disc.The results demonstrate that repetitive freezing-thawing damage the structure of myofibril seriously,change the nutrition components and decline the mutton quality of Lanzhou Fat-tailed sheep.
国家科技期刊平台
NSTL
万方数据
维普
