Velasco S, Cañeque V, Lauzurica S, Pérez C, Huidobro F
Instituto Nacional de Investigación y Tecnologı́a Agraria y Alimentaria, Departamento de Tecnologı́a de los Alimentos, Carretera de la Coruña, km 7.5, 28040 Madrid, Spain.
Meat Sci. 2004 Feb;66(2):457-65. doi: 10.1016/S0309-1740(03)00134-7.
Two kinds of feed (commercial concentrate vs whole supplemented barley) were compared in unweaned lambs and lambs weaned at 40 days of age, fattened at pasture and slaughtered at 28 kg live weight, in order to observe their effects on meat quality and fatty acid composition. The weaning status influenced fatness; unweaned lambs displayed a greater carcass fatness score and more kidney knob and channel fat than weaned lambs. Compared with the unweaned animals, weaned lambs exhibited higher pH values at 0 h and 45 min in the m. longissimus thoracis (LT) and at 45 min and 24 h in the m. semitendinosus. The redness index (a*) of the m. LT of weaned lambs was higher than that of unweaned lambs, and lambs fed concentrate displayed a higher yellowness index (b*) and a higher Hue value than those given whole barley. Water-holding capacity did not vary with the treatments studied. The proportion of saturated fatty acids (SFA) in intramuscular fat was higher (P⩾0.001) in unweaned lambs than in weaned ones while, on the other hand, the latter displayed a higher proportion of monounsaturated fatty acids (MUFA) and a higher n-6/n-3 ratio in the same tissue. As was the case with intramuscular fat, the subcutaneous fat of unweaned lambs exhibited higher proportions of medium-chain fatty acids (C12:0, C14:0 y C16:0) and lower ones of stearic (C18:0) and oleic (C18:1) fatty acids than that of weaned lambs. Higher levels of heptadecenoic acid (C17:1) were found in the subcutaneous fat of lambs fed whole barley than in that of lambs given concentrate. PUFA/SFA and n-6/n-3 ratios were lower in the m. LT than in the m. quadriceps femoris.
在未断奶羔羊和40日龄断奶羔羊中比较了两种饲料（商业浓缩饲料与整粒补充大麦），这些羔羊在牧场育肥，体重达28千克时屠宰，以观察它们对肉质和脂肪酸组成的影响。断奶状态影响脂肪含量；未断奶羔羊的胴体脂肪评分更高，肾周脂肪和肋间脂肪比断奶羔羊更多。与未断奶动物相比，断奶羔羊的胸最长肌（LT）在0小时和45分钟时以及半腱肌在45分钟和24小时时的pH值更高。断奶羔羊LT肌的红度指数（a*）高于未断奶羔羊，且饲喂浓缩饲料的羔羊的黄度指数（b*）和色调值高于饲喂整粒大麦的羔羊。持水力不受所研究处理的影响。未断奶羔羊肌肉脂肪中饱和脂肪酸（SFA）的比例高于断奶羔羊（P⩾0.001），而另一方面，后者在同一组织中显示出更高的单不饱和脂肪酸（MUFA）比例和更高的n-6/n-3比值。与肌肉脂肪情况相同，未断奶羔羊的皮下脂肪中中链脂肪酸（C12:0、C14:0和C16:0）的比例高于断奶羔羊，而硬脂酸（C18:0）和油酸（C18:1）的比例则较低。饲喂整粒大麦的羔羊皮下脂肪中的十七碳烯酸（C17:1）含量高于饲喂浓缩饲料的羔羊。LT肌中的多不饱和脂肪酸/饱和脂肪酸（PUFA/SFA）和n-6/n-3比值低于股四头肌中的比值。
