Zarkadas C G, Maloney S A
Eastern Cereal and Oilseed Research Centre, Research Branch, Agriculture and Agri-Food Canada, Ottawa, Ontario.
Poult Sci. 1998 May;77(5):770-9. doi: 10.1093/ps/77.5.770.
The objective of this study was to assess the protein quality of the myofibrillar and connective tissue proteins of chicken gizzard. Protein fractions were isolated from White Leghorn chicken gizzards and quantified by detailed amino acid analysis. This quantification involved repeated extractions of ground gizzards first with Triton X-100, then with low ionic strength imidazole-buffered saline (pH 7.1), followed by either 2% SDS or by 5 M guanidine hydrochloride. The total soluble intracellular protein fraction averaged 86.3% of the total protein and the insoluble extracellular connective tissue proteins comprised the remaining 13.7%. These fractions differed significantly in their essential amino acid (EAA) profiles, with the soluble intracellular fraction having the highest percentage EAA9 (48.6 to 49.0%) and the insoluble connective tissue fraction varying from 20.8 to 23%, compared to the FAO/WHO reference pattern value of 33.9% for a 2- to 5-yr-old child. Calculated protein efficiency ratios (PER) for intracellular proteins averaged 3.02 compared with a value of 1.65 for the extracellular matrix proteins. These results provide an accurate assessment of the protein quality of smooth muscle proteins of chicken gizzard and may prove valuable for industrial control of the amount of connective tissue added to formulations of meats and poultry products.
本研究的目的是评估鸡胗肌原纤维蛋白和结缔组织蛋白的蛋白质质量。从白来航鸡的胗中分离出蛋白质组分，并通过详细的氨基酸分析进行定量。这种定量包括首先用 Triton X-100 对研磨后的胗进行反复提取，然后用低离子强度的咪唑缓冲盐水（pH 7.1）提取，接着用 2% SDS 或 5 M 盐酸胍提取。总可溶性细胞内蛋白质组分平均占总蛋白的 86.3%，不溶性细胞外结缔组织蛋白占其余的 13.7%。这些组分的必需氨基酸（EAA）谱有显著差异，可溶性细胞内组分的 EAA9 百分比最高（48.6%至 49.0%），不溶性结缔组织组分则在 20.8%至 23%之间，而 2 至 5 岁儿童的 FAO/WHO 参考模式值为 33.9%。细胞内蛋白质的计算蛋白质效率比（PER）平均为 3.02，而细胞外基质蛋白的值为 1.65。这些结果提供了对鸡胗平滑肌蛋白蛋白质质量的准确评估，可能对工业控制肉类和家禽产品配方中添加的结缔组织量具有重要价值。
