) PER( و نسبت كارآيي پروتيين )RNPR( ، نسبت خالص نسبي پروتيين )NPR( ارزيابي زيستي پروتيين سويا با روشهاي نسبت خالص پروتيين

Biological Evaluation of Soy Bean Protein Quality by Using Net Protein Ratio (NPR), Relative Net Protein Ratio (RNPR), and Protein Efficiency Ratio (PER) Methods

Introduction: Evaluation the quality of food proteins has a great importance in biological and economical view. However, biological, microbiological, chemical and combined methods have been used and introduced for determining quality of proteins. Among existed methods, NPR, RNPR and PER have been suggested as appropriate methods for determining quality of proteins. This study has been conducted to determine the quality of soya protein by using the mentioned methods on a soya product in 2003. Material and Methods: This study with experimental method has been made on 24 male wistar rats, aged 21 days, under 3 food diets in 8 groups: Soya (10% protein), Casein+Methionine (10% protein) and control (non protein). Period of study for NPR was 14 days. Protein intake and rat weight gain were determined for calculating NPR. Period of study for PER was 28 days. Protein intake and weight gain of animals were determined. Rate of NPR, RNPR and PER were evaluated by T test. Results: Indicators of NPR were calculated 3.65±0.35 and 4.37±0.48 for soya and Casein+Methionin respectively (P<0.01) and RNPR was 83. Indicator of PER were 2.28±0.35 and 3.04±0.24 for soya and Casein+Methionin respectively (P<0.001) and soya PER ratio to casein was 75%. Conclusion: Soya protein as compared with Casein has low but appropriate quality. The results showed that NPR, RNPR and PER for determine soy bean quality is compatible with other studies.