三段冷却方式对淘汰奶牛背最长肌宰后生化变化和嫩度的影响  

Effects of three-step chilling on postmortem physicochemical characteristics and tenderness of M.longissimus dorsi in culling cow

作　　者：孟质文[1] 张瑞红[1] 安玥[1] 薛冰[1] 韩冬雪[1] 贺旺琳 俞龙浩[1] 

机构地区：[1]黑龙江八一农垦大学食品学院,黑龙江大庆163319

出　　处：《中国兽医学报》2014年第4期596-600,共5页Chinese Journal of Veterinary Science

基　　金：大庆市科技局<产业结构调整重大科技资助项目>(scyh-2011-50)

摘　　要：分别取淘汰奶牛的左侧背最长肌,在2℃冷却24h作为对照组;右侧背最长肌在2℃冷却3h,15℃冷却6h,然后在2℃冷却15h（三段冷却方式）,作为处理组。测定结果显示,对照组的肌肉中心温度宰后10h时已降至4.1℃,处理组肌肉中心温度在宰后3-9h维持在（16±0.5）℃范围内,到宰后13.5h降到4℃。处理组宰后8和24h的肌糖原含量显著低于对照组,宰后8h处理组的pH值显著低于对照组。这一结果表明,宰后4h开始处理组的肌糖原分解速度快于对照组,从而加快宰后处理组pH值的降低速度。处理组宰后8,24,48h的肌节长度显著大于对照组,宰后1和3d的剪切力值显著低于对照组。这一结果提示,淘汰奶牛宰后在2℃持续冷却,可能导致背最长肌的严重冷收缩,从而对嫩度产生负面影响,三段冷却方式可以改善淘汰奶牛宰后嫩度品质。The left side side were respective of M. longissimus dorsi were chilled at 2℃ for 24 h as control. The right chilled at 2℃ for 3 h,at 15℃ for 6 h,at 2℃ for 15 h as treatment. The result showed that the core temperature of control was reduced by 4.1℃ at 10 h postmortem. The core temperature of treatment was maintained in the range of （16±0.5）℃ at 3-9 h postmortem,and reduced to 4℃ at 13.5 h postmortem. Treatment had lower glycogen than control at 8 and 24 h postmortem and had lower pH value than control at 8 h postmortem. This result showed the gly- cogenolysis of treatment muscle was faster than control,thus accelerated pH reduction. Treatment muscle had longer sarcomeres than control at 8,24,48 h significantly. The shear force of treatment was significantly lower than control at day 1 and day 3. The result indicated chilling at 2℃ may re- sult in severe cold shorting and had negative impact on the tenderness, however three-step chilling can improve the tenderness postmortem M. longissimus dorsi in cull cow.

关 键 词：淘汰奶牛 宰后冷却 pH值 肌糖原含量 肌节长度 剪切力 

分 类 号：S823[农业科学—畜牧学]