西藏雅江雪牛与牦牛肉质特性比较研究

目的研究雅江雪牛与牦牛肉食用品质及营养成分含量的差异。方法选择健康成年(5～7岁)的西藏公牦牛、公雅江雪牛和母雅江雪牛各6头,对其体尺、背最长肌基本营养成分和氨基酸、脂肪酸以及食用品质指标进行分析。结果雅江雪牛肉的蛋白质含量较丰富,属于高蛋白性食品。公雅江雪牛和母雅江雪牛肉中必需氨基酸与总氨基酸的比值(essential amino acid/total amino acid,EAA/TAA)分别为44.7%和44.8%,必需氨基酸与非必需氨基酸的比值(essential amino acid/nonessential amino acids,EAA/NEAA)分别为80.7%和80.8%,表明雅江雪牛肉为优质蛋白;雅江雪牛的脂肪含量较高,相对于普通牦牛,具有更好的风味品质;雅江雪牛蒸煮损失率较低,具有较好的加工性能;雅江雪牛颜色鲜红,更符合消费者喜好。结论雅江雪牛生长速度快,脂肪含量相较于传统牦牛明显升高,能够在西藏有限的牧草资源环境中产生相对于牦牛更高的经济利用价值,对西藏地区的肉牛产业起到良好的促进作用。     

Starch granule-associated proteins of hull-less barley (Hordeum vulgare L.) from the Qinghai-Tibet Plateau in China

BACKGROUND: The starch granule‐associated proteins (SGAPs) are the minor components of the starch granules and a majority of them are believed to be starch biosynthetic enzymes. The Qinghai‐Tibet Plateau in China, one of the centres of origin of cultivated barley, is abundant in hull‐less barley resources which exhibit high polymorphism in SGAPs. RESULTS: The SGAPs of hull‐less barley from Qinghai‐Tibet Plateau were analysed by one‐dimensional (1‐D) SDS‐PAGE, 2‐D PAGE and ESI‐Q‐TOF MS/MS. In the 1‐D SDS‐PAGE gel, four proteins including a 80 kDa starch synthase, actin, actin 4 and ATP synthase β‐subunit were identified as novel SGAPs. A total of six different bands were identified as starch granule‐bound starch synthase I (GBSSI) and the segregation of the novel GBSSI bands in F₁ and F₂ seeds derived from yf127 × yf70 was in accordance with Mendel's law. In the 2‐D PAGE gel, 92 spots were identified as 42 protein species which could be classified into 15 functional groups. Thirteen protein species were identified as SGAPs for the first time and multiple spots were identified as GBSSI. CONCLUSION: This study revealed novel SGAPs in hull‐less barley from the Qinghai‐Tibet Plateau in China and these will be significant in further studies of starch biosynthesis in barley. Copyright © 2011 Society of Chemical Industry