新疆褐牛不同部位牛肉肌纤维类型及品质差异研究

为了研究新疆褐牛不同部位牛肉肌纤维类型组成及品质差异,测定了冈上肌、冈下肌、臂三头肌、腰大肌、背最长肌、半腱肌、半膜肌和股二头肌的肌纤维特性和品质特性,并通过相关性分析研究了牛肉品质和肌纤维特性之间的相关性。结果显示腰大肌、背最长肌和股二头肌分别具有最高的Ⅰ型、ⅡA型和ⅡB型肌纤维比例,八个部位肉的肌纤维直径为ⅡB型>ⅡA型>Ⅰ型,且腰大肌三种肌纤维类型直径均小于其他部位。冈上肌具有较低的b^*值,冈下肌具有较低的剪切力、蒸煮损失率;臂三头肌具有较高的剪切力,腰大肌具有较低的剪切力、硬度、胶着性和pH,较高的粘聚性和压力失水率;背最长肌具有较低的咀嚼性、回复性和弹性;半腱肌具有较低的压力失水率、粘聚性和回复性,较高的L^*值;半膜肌具有较低的L^*值和咀嚼性,股二头肌具有较高的弹性、胶着性和咀嚼性。Ⅰ型、ⅡA型和ⅡB型纤维面积、直径与剪切力、硬度和蒸煮损失显著正相关(p<0.05),与压力失水率显著负相关(p<0.01);Ⅰ型肌纤维比例与硬度、剪切力显著负相关(p<0.05),ⅡB型肌纤维比例与剪切力正相关。结果表明,肌肉部位显著影响牛肉品质,特别是嫩度,增加Ⅰ型肌纤维比例、减少ⅡB型肌纤维比例均有利于提高牛肉嫩度。

Study on the difference of muscle fiber types and quality in different parts of Xinjiang brown cattle

In order to study the type and quality of muscle fiber in different parts of Xinjiang brown cattle,muscle fiber and quality characteristics of beef cuts of Xinjiang brown cattle such as supraspinatus(SU),infraspinatus(IF),triceps brachii(TB),psoas major(PM),longissimus dorsi(LD),semitendinosus(ST),semimembranosus(SM)and biceps femoris(BF)were determined,and the correlation between beef quality and muscle fiber properties was studied by correlation analysis. The results showed that PM,LD and BF had the highest muscle fiber ratio of type Ⅰ,type ⅡA and type ⅡB fibers respectively. The diameter order was type ⅡB>ⅡA>Ⅰ. The diameters of the type Ⅰ,type ⅡA and type ⅡB fiber of PM were smaller than other parts. SU had lower b* value,IF had lower WBSF,cooking loss. TB had higher WBSF,PM had lower Warner-Bratzler shear force(WBSF),hardness,gumminess,and pH value,and had higher cohesiveness and pressing loss. LD had lower chewiness,resilience and springiness. ST had lower pressing loss,cohesiveness and resilience,and had higher L* value. SM had lower L* value and chewiness,BF had higher springiness,cohesiveness and chewiness. Muscle fiber area and diameter of type Ⅰ,ⅡA and ⅡB fibers were positive correlated to WBSF,hardness and cooking loss(p<0.05). Muscle fiber area and diameter of type Ⅰ,ⅡA and ⅡB fibers were negative correlated to pressing loss(p<0.01).The muscle fiber ratio of type Ⅰ was negative correlated to hardness and WBSF(p<0.05). The muscle fiber ratio of type ⅡB was positive correlated to WBSF(p<0.05). The results showed that the muscle parts significantly affected the quality of beef,especially tenderness. Therefore,increasing the proportion of type I fiber,reducing the proportion of type ⅡB fiber would be beneficial to improve the beef tenderness.