CIISA, Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Lisboa, Portugal.
J Sci Food Agric. 2012 Sep;92(12):2428-35. doi: 10.1002/jsfa.5648. Epub 2012 Apr 3.
Consumer awareness regarding the intake of beef of organic origin is strongly associated with the beneficial outcomes to human health, the environment and animal welfare. In this paper the effects of slaughter season and muscle type on the fatty acid composition, conjugated linoleic acid (CLA) isomeric profile, total cholesterol, α-tocopherol and β-carotene contents and nutritional quality of intramuscular fat in organic beef (n = 30) are reported for the first time.
Organic beef showed a very low total lipid content, with seasonal changes in the levels of some fatty acids, CLA isomers, n-6/n-3 polyunsaturated fatty acid (PUFA) ratio, total cholesterol and β-carotene. In addition, differences between longissimus lumborum (relatively red) and semitendinosus (relatively white) muscles were found for many fatty acids, specific CLA contents, many CLA isomers and both PUFA/saturated fatty acid (SFA) and n-6/n-3 ratios. However, in spite of the seasonal and carcass variations, all organic meats analysed had values of beef similar to pasture-fed cattle.
From a nutritional perspective, organic meat from both slaughter seasons seems to have high CLA contents, PUFA/SFA and n-6/n-3 indices within the recommended values for the human diet. The data indicate that intramuscular fat in organic meat has a high nutritional value throughout the year.
消费者对有机牛肉摄入的认识与其对人类健康、环境和动物福利的有益影响密切相关。本文首次报道了屠宰季节和肌肉类型对有机牛肉（n=30）肌内脂肪的脂肪酸组成、共轭亚油酸（CLA）异构体分布、总胆固醇、α-生育酚和β-胡萝卜素含量以及营养质量的影响。
有机牛肉的总脂质含量非常低，一些脂肪酸、CLA 异构体、n-6/n-3 多不饱和脂肪酸（PUFA）比、总胆固醇和β-胡萝卜素的水平随季节变化而变化。此外，在许多脂肪酸、特定的 CLA 含量、许多 CLA 异构体以及 PUFA/SFA 和 n-6/n-3 比值方面，腰大肌（相对红色）和半腱肌（相对白色）之间存在差异。然而，尽管存在季节性和胴体变化，但分析的所有有机肉类的价值都与放牧牛相似。
从营养角度来看，来自两个屠宰季节的有机肉似乎具有高 CLA 含量、PUFA/SFA 和 n-6/n-3 指数，在人类饮食的推荐值范围内。数据表明，全年有机肉的肌内脂肪具有很高的营养价值。
