猪全血蛋白质营养价值的评价

猪全血蛋白质的赖氨酸含量高(7.8g/16gN),异亮氯酸含量低(0.5g/16gN),为第一限制氨基酸,亮氨酸/异亮氨酸比值(26/1)过高。猪全血蛋白质的真实消化率(TD)、生物价(BV)和净蛋白质比值(NPR)分别为92.4％,16.5和0。大鼠体重下降。蛋白质功效比值(PER)不能计算,表明其营养价值差。但它与面粉蛋白质有很好的互补作用,全血蛋白质与面粉蛋白质2∶8混合为最佳比例(相当于在面粉中添加3％的猪血粉),其营养价值显著提高,BV、PFR和NPR分别从面粉的55.3、1.01和3.1上升至77.3、2.46和4.3。

EVALUATION OF THE NUTRITIVE VALUE OF PORCINE WHOLE BLOOD PROTEIN

The Present study designed according to AOAC is conducted to evaluate the practical protein quality of the porcine blood solely and mixed with other dietary proteins.Proximate analysis shows the average contents of crude protein and water in the spray-drying porcine blood are 85.0% and 12.0% respectively.The porcine blood protein is scant of Isoleucine (0.5%) and its Leu/Ile ratio is as high as 26. The amino acid pattern results in poor protein quality of the porcine blood, with BV, NPU and NPR value being only 16.5, 15.5 and 0 respectively. Therefore diets containing porcine blood as a sole source of protein can not maintain the normal body weight of rats.But porcine whole blood protein is rich in Lysine (7.8%) . When the spray-drying porcine blood is mixed with the wheat flour in proportion of 3%, the protein quality of the mixed dietary protein comparing with either of its constitutional proteins, is improved remarkably and its nutritive parameter values (BV:73.3, NPU: 61.8, PER: 2.46, Calbrated PER:1.9 and NPR: 4.3 respectively) are higher than those of the wheat flour protein (BV: 55.3, NPU: 46.6, PER: 1.01, Calibrated PER: 0.8 and NPR: 3.1 respectively).