加热介质和时间对牦牛肉品质的影响

Quality changes of yak meat under different heat medium and time

为研究不同加热介质和时间对牦牛肉品质的影响。采用水浴和蒸汽2种介质对牦牛肉分别加热10,20,30,40,50,60min后取样,测定牦牛肉蒸煮损失、热收缩率、肉色、剪切力和质构的变化。结果表明:水浴和蒸汽加热牦牛肉的蒸煮损失随加热时间的延长而显著增加(P<0.05);在加热10~40min时,水浴加热的热收缩率大于蒸汽加热,40~60 min时蒸汽加热的热收缩率大于水浴加热;在10~60 min时,水浴加热的L~*值下降了4.82%,而蒸汽加热的L~*值增加了3.84%,水浴加热的a~*值下降了13.63%,蒸汽加热的a~*值先下降后上升;蒸汽加热的剪切力值大于水浴加热的;在水浴和蒸汽加热中牦牛肉硬度随加热时间延长显著增加(P<0.05),内聚性和弹性呈波动变化趋势,胶着性和咀嚼性总体呈下降趋势。相关性表明,水浴与蒸汽加热与牦牛肉各指标具有较强的相关性。总体来看,当水浴和蒸汽加热40 min时,牦牛肉各项品质指标较好;水浴加热的牦牛肉蒸煮损失较大、质构较好,而蒸汽加热的牦牛肉蒸煮损失较小、质构较差。

Cooking loss, heat shrinkage rate, color, shear force, and texture of yak meat were measured, which were heated by water and steam at 10, 20, 30, 40, 50, 60min, respectively, and the correla- tion of heat time and quality were analyzed. The results showed that cooking loss of yak meat significantly increased with the extension of heat time （P〈0.05）, and the increased rate of cooking loss heated by water 21.21% higher than by steam. The heat shrinkage rate of yak meat by water bigger than by steam after being heated from 10 rain to 40 min, and the heat shrinkage rate of heated by steam was bigger than by water after heated from 40 min to 60 rain. The L＊ value and a ＊ value decreased 4.82% and 13.63% of yak meat heated by water 10 min to 60 rain, respectively. And the L ＊ value increased 3.84% of yak meat heated by steam 10 min to 60 min; thea ＊ value decreased at first then increased later. The shear force of yak meat heated by steam larger than heated by water, and the shear force of yak meat which heated by steam and water 40 min is （7.79±0.16） kg and （4.96±0.79） kg. The hardness of yak meat heated by water and steam increases signif- icantly with the extension of heat time （P〈0.05）, the cohesiveness and springiness were fluctuating, gumminess and chewiness had the tendency of decrease. Correlation showed that the time of heated by water have strong correlation with L ＊ value, hardness, springiness and gumminess, and the time of heated by steam have strong corre lation with cooking loss, heat shrinkage rate, a ＊ value, shear force, cohesiveness and chewiness. In summary, the yak meat which heated by water and steam 40min will have better quality, the yak meat heated by water will have larger cooking loss and better texture, and the yak meat heated by steam will have small cooking loss and worse texture.