To compare the quality of yak meat with that of other livestock, the growth and development of yak from birth to 48-month old were measured, slaughter tests of 6-, 24-, 48-month old were made. It can improve meat perf...To compare the quality of yak meat with that of other livestock, the growth and development of yak from birth to 48-month old were measured, slaughter tests of 6-, 24-, 48-month old were made. It can improve meat performance on yak to crossbreed with beef cattle or wild yak, to improve traditional feeding and management, etc.展开更多
Female domesticated yaks were artificially inseminated with semen taken from wild yaks and the offspring used to form a nucleus breeding herd of crossbred animals. The meat production of the first generation(F1 ×...Female domesticated yaks were artificially inseminated with semen taken from wild yaks and the offspring used to form a nucleus breeding herd of crossbred animals. The meat production of the first generation(F1 × F2)from breedtng within the nucleus herd was assessed by slaughter and carcass dissection of males. One group(no. =14)was slaughtered at 6 months of age and the second(no. = 12)at 18months. Crossbred yaks were significantly heavier(P＜0.01)at 6 months(74.7(s. e. 10.41)kg v. 59.8(s.e. 10.23)kg)and at 18 months(150.5(s. e. 56.1)kg v. 117.7(s. e. 17.4)kg)than domesticated ones,The killing-out proportion(0.47)was similar at both ages and for both groups of animals. Carcass weight,meat weight and the yield of prime cuts were higher for crossbred animals than for domestic yak at both ages.展开更多
On the Qinghai-Tibet Plateau,a place so remote where natural resources are scarce at best, producing anything is more than just a chore. As a result, the local food culture is like nothing seen anywhere else.
建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-...建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-HeavyWAX色谱柱(30 m×0.25 mm×0.25μm)分离15种N-亚硝胺,在多重反应监测(MRM)模式下进行测定,外标法定量。结果表明,15种N-亚硝胺分离性能良好,在0.1~200μg/L范围内线性关系良好,相关系数(r^(2))≥0.999 0;检出限(LOD)为0.05~0.20μg/kg,定量限(LOQ)为0.10~0.50μg/kg;在1倍、2倍和10倍LOQ 3个添加水平下的平均回收率分别为79.4%~102.1%、80.6%~109.5%、83.0%~110.6%,相对标准偏差(RSD)为0.8%~16.0%。应用建立的方法检测2种不同加工工艺的市售样品,其中7种N-亚硝胺类化合物(N-亚硝基二甲胺、N-亚硝基二异丁胺、N-亚硝基二正丁胺、N-亚硝基甲基苯胺、N-亚硝基乙基苯胺、N-亚硝基吡咯烷、N-亚硝基二苯胺)均有不同程度检出,平均含量为0.08~20.18μg/kg,且熟制风干牦牛肉中N-亚硝胺的检出率和平均含量均高于传统生制风干牦牛肉。该方法实现了前处理的自动化,相较于其他传统方法,操作简单,实验效率高,人为影响因素小,检测灵敏度高,适用于风干牦牛肉中15种N-亚硝胺的快速测定,为研究肉制品中N-亚硝胺的测定提供了方法支持。展开更多
将牦牛肉烹饪至不同中心温度(40、50、60、70、80℃)后,对其肌原纤维蛋白进行模拟体外胃肠消化实验,并测定其肌原纤维蛋白的消化率以及消化前后的总羰基含量、总巯基含量、Schiff碱含量等指标,还利用紫外吸收光谱、内源荧光光谱以及十...将牦牛肉烹饪至不同中心温度(40、50、60、70、80℃)后,对其肌原纤维蛋白进行模拟体外胃肠消化实验,并测定其肌原纤维蛋白的消化率以及消化前后的总羰基含量、总巯基含量、Schiff碱含量等指标,还利用紫外吸收光谱、内源荧光光谱以及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)分析蛋白样品,探究牦牛肉蛋白质在胃肠消化过程中的氧化及消化规律。经胃、肠消化后,中心温度为60℃的牦牛肉总蛋白酶水解率最高(88.64%)。与原料肉相比,中心温度为80℃的牦牛肉蛋白质胃蛋白酶水解率和总蛋白酶水解率分别降低了34.10%和22.47%,胰蛋白酶水解率提高了75.34%;其经胃、肠消化后的总羰基含量与原料肉相比分别升高了81.42%和77.40%,总巯基含量分别降低了30.02%和36.43%。随着中心温度升高,Schiff碱含量逐渐增大,紫外吸收光谱的吸光度显著增强,内源荧光光谱的荧光强度显著降低,SDS-PAGE图谱显示经消化后蛋白质发生严重降解至条带消失。结果表明:中心温度为60℃时牦牛肉的消化率最高,80℃时牦牛肉的蛋白质氧化程度最强,在胃肠消化过程中进一步加剧。展开更多
文摘To compare the quality of yak meat with that of other livestock, the growth and development of yak from birth to 48-month old were measured, slaughter tests of 6-, 24-, 48-month old were made. It can improve meat performance on yak to crossbreed with beef cattle or wild yak, to improve traditional feeding and management, etc.
文摘Female domesticated yaks were artificially inseminated with semen taken from wild yaks and the offspring used to form a nucleus breeding herd of crossbred animals. The meat production of the first generation(F1 × F2)from breedtng within the nucleus herd was assessed by slaughter and carcass dissection of males. One group(no. =14)was slaughtered at 6 months of age and the second(no. = 12)at 18months. Crossbred yaks were significantly heavier(P＜0.01)at 6 months(74.7(s. e. 10.41)kg v. 59.8(s.e. 10.23)kg)and at 18 months(150.5(s. e. 56.1)kg v. 117.7(s. e. 17.4)kg)than domesticated ones,The killing-out proportion(0.47)was similar at both ages and for both groups of animals. Carcass weight,meat weight and the yield of prime cuts were higher for crossbred animals than for domestic yak at both ages.
文摘On the Qinghai-Tibet Plateau,a place so remote where natural resources are scarce at best, producing anything is more than just a chore. As a result, the local food culture is like nothing seen anywhere else.
文摘建立了一步式QuEChERS自动提取和净化技术结合气相色谱-串联质谱同时测定风干牦牛肉中15种N-亚硝胺的分析方法。样品水化后,经乙腈提取,加入4.0 g MgSO_(4)和1.0 g NaCl除水,经十八烷基硅烷(C_(18))和N-丙基乙二胺(PSA)填料净化,采用DB-HeavyWAX色谱柱(30 m×0.25 mm×0.25μm)分离15种N-亚硝胺,在多重反应监测(MRM)模式下进行测定,外标法定量。结果表明,15种N-亚硝胺分离性能良好,在0.1~200μg/L范围内线性关系良好,相关系数(r^(2))≥0.999 0;检出限(LOD)为0.05~0.20μg/kg,定量限(LOQ)为0.10~0.50μg/kg;在1倍、2倍和10倍LOQ 3个添加水平下的平均回收率分别为79.4%~102.1%、80.6%~109.5%、83.0%~110.6%,相对标准偏差(RSD)为0.8%~16.0%。应用建立的方法检测2种不同加工工艺的市售样品,其中7种N-亚硝胺类化合物(N-亚硝基二甲胺、N-亚硝基二异丁胺、N-亚硝基二正丁胺、N-亚硝基甲基苯胺、N-亚硝基乙基苯胺、N-亚硝基吡咯烷、N-亚硝基二苯胺)均有不同程度检出,平均含量为0.08~20.18μg/kg,且熟制风干牦牛肉中N-亚硝胺的检出率和平均含量均高于传统生制风干牦牛肉。该方法实现了前处理的自动化,相较于其他传统方法,操作简单,实验效率高,人为影响因素小,检测灵敏度高,适用于风干牦牛肉中15种N-亚硝胺的快速测定,为研究肉制品中N-亚硝胺的测定提供了方法支持。
文摘将牦牛肉烹饪至不同中心温度(40、50、60、70、80℃)后,对其肌原纤维蛋白进行模拟体外胃肠消化实验,并测定其肌原纤维蛋白的消化率以及消化前后的总羰基含量、总巯基含量、Schiff碱含量等指标,还利用紫外吸收光谱、内源荧光光谱以及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)分析蛋白样品,探究牦牛肉蛋白质在胃肠消化过程中的氧化及消化规律。经胃、肠消化后,中心温度为60℃的牦牛肉总蛋白酶水解率最高(88.64%)。与原料肉相比,中心温度为80℃的牦牛肉蛋白质胃蛋白酶水解率和总蛋白酶水解率分别降低了34.10%和22.47%,胰蛋白酶水解率提高了75.34%;其经胃、肠消化后的总羰基含量与原料肉相比分别升高了81.42%和77.40%,总巯基含量分别降低了30.02%和36.43%。随着中心温度升高,Schiff碱含量逐渐增大,紫外吸收光谱的吸光度显著增强,内源荧光光谱的荧光强度显著降低,SDS-PAGE图谱显示经消化后蛋白质发生严重降解至条带消失。结果表明:中心温度为60℃时牦牛肉的消化率最高,80℃时牦牛肉的蛋白质氧化程度最强,在胃肠消化过程中进一步加剧。
