Abstract
Protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR) and relative NPR (RNPR) values, and amino acid scores were calculated for 20 food products (casein, casein + Met, beef salami, skim milk, tuna, chicken frankfurters, sausage, heated skim milk, peanut butter, rolled oats, soy isolate, chick peas, pea concentrate, kidney beans, wheat cereal, pinto bean, lentils, rice-wheat gluten cereal, macaroni-cheese, and beef stew). In most cases, PER, RPER, NPR or RNPR ranked the products in the same order and positive correlations among the protein quality methods were highly significant (r=0.98−0.99). Amino acid scores (based on the first limiting amino acid, Lys-Met-Cys, Lys-Met-Cys-Trp or lys-Met-Cys-Trp-Thr) were positively correlated to the PER, RPER, NPR or RNPR data (r=0.61−0.75). Inclusion of the correction for true digestibility of protein improved the correlations between amino acid scores and the indices based on rat growth. The correlations were especially high between Lys-Met-Cys scores (corrected for true digestibility of protein) and PER, RPER, NPR or RNPR (r=0.86−0.91). Inclusion of the correction for true digestibility of individual amino acids did not result in further improvements of the correlations in most cases. It is concluded that adjusting amino acid scores for true digestibility of protein would be sufficient and further correction for digestibility of amino acids would be unnecessary in mixed diets.
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Sarwar G, Peace RW, Botting HG, Brulé D (1989) Digestibility of protein and amino acids in selected foods as determined by a rat balance method. Plant Foods Hum Nutr 39: 23–32
Sarwar G, Peace RW (1986) Comparisons between true digestibility of total nitrogen and limiting amino acids in vegetable proteins fed to rats. J Nutr 116: 1172–1184
Eggum BO (1968) Nutritional evaluation of proteins by laboratory animals. In: Bender AE, Kihlberg R, Lofquist B, Munck L (eds) Evaluation of Novel Protein Products. New York, NY: Pergamon Press, pp. 117–125
Sarwar G, Sosulski FW, Bell JM (1977) Availability of amino acids in legumes and legume-wheat blends. Can Inst Food Sci Technol J 10: 31–35
Sarwar G (1984) Available amino acid score for evaluating protein quality of foods. J Assoc Off Anal Chem 67: 623–626
McLaughlan JM, Anderson GH, Hackler LR, Hill DC, Jansen GR, Keith MO, Sarwar G, Sosulski FW (1980) Assessment of rat growth methods for estimating protein quality: interlaboratory study. J Assoc Off Anal Chem 63: 462–467.
Hackler LR, Bodwell CE, Happich ML, Phillips JG, Derse PH, Elliott JG, Hartnagle RE Jr, Hopkins DT, Kapiszka EL, Mitchell GV, Parson GF, Prescher EE, Robaidek ES, Womack M (1984) Protein efficiency ratio. AACC/ASTM collaborative study. J Assoc Off Anal Chem 67: 66–77
Happich ML, Bodwell CE, Hackler LR, Phillips JG, Derse PH, Elliott JG, Hartnagle RE Jr, Hopkins DT, Kapiszka EL, Mitchell GV, Parsons GF, Prescher EE, Robaidek ES, Womack M (1984) Net protein ratio data: AACC-ASTM collaborative study. J Assoc Off Anal Chem 67: 255–262
Sarwar G, Blair R, Friedman M, Gumbmann MR, Hackler LR, Pellett PL, Smith TK (1984) Inter- and intra-laboratory variability in rat growth assays for estimating protein quality of foods. J Assoc Off Anal Chem 67: 976–81
FAO/WHO/UNU Joint Expert Consultation (1984) Energy and Protein Requirements; Geneva: World Health Org Tech Rept Ser 724
Bodwell CE (1981) Use of amino acid data to predict protein nutritive value for adults. In: Bodwell CE, Adkins JS, Hopkins DT (eds) Protein Quality in Humans: Assessment andin vitro Estimation. Westport, CT: AVI Publishing Company, pp. 340–373
Oser BL (1951) Method for integrating essential amino acid content in the nutritional evaluation of protein. J Am Dietet Assoc 27: 396–402
Steele RGD, Torrie J (1980) Principles and Procedures of Statistics, 2nd edn. New York, NY: McGraw-Hill Book Co., pp. 272–277
Sarwar G, McLaughlan JM (1981) Relative net protein ratio method for evaluating protein quality. Nutr Rep Int 23: 1157–1166
Mitchell GV, Jenkins MY, Grundel E (1989) Protein efficiency ratio and net protein ratios of selected protein foods. Plant Foods Hum Nutr 39: 53–58
Sarwar G, Botting HG, Peace RW, Noel FJ (1981) Effect of methionine supplemented legume protein products on liver fat in rats. Nutr Rep Int 24: 267–276
Satterlee LD, Kendrick JG, Jewell DK, Brown WD (1981) Estimating apparent protein digestibility fromin vitro assays, In: Bodwell CE, Adkins JS, Hopkins DT (eds) Protein Quality in Humans: Assessment andin vitro Estimation. Westport, CT: AVI Publishing Company, pp. 316–339
Eggum BO, Hansen I, Larsen T (1989) Protein quality and digestible energy of selected foods determined in balance trials with rats. Plant Foods Hum Nutr 39: 13–21
Hsu HW, Vavak DH, Satterlee LD, Miller GA (1977) A multienzyme technique for estimating protein digestibility. J Food Sci 42: 1269–1273
Satterlee LD, Marshall HF, Tennyson JM (1979) Measuring protein quality. JAOCS 56: 103–109
Pedersen B, Eggum BO (1981) Prediction of protein digestibility byin vitro procedures based on two multienzyme systems. Zeitschrift fur Tierphysiologie, Tierernahrung und Futtermittelkunde 45: 190–200
Pellet PL, Young VR (eds) (1980) Nutrition Evaluation of Food Proteins. Tokyo: The United Nations University, pp. 103–133
Steinke FH (1979) Measuring protein quality of foods. In: Wilcke HL, Hopkins DT, Waggle DH (eds) Soy Protein and Human Nutrition. New York, NY: Academic Press, pp. 307–312
Sarwar G, Peace RW, Botting HG (1985) Corrected relative net protein ratio (CRNPR) method based on differences in rat and human requirements for sulfur amino acids. J Assoc Off Anal Chem 68: 689–693
Pedersen B, Eggum BO (1983) Prediction of protein digestibility by an in vitro enzymatic pH-stat procedure. Z Tierphysiol Tierernahrg-Futter mittelkde 49: 266–277
Sarwar G (1987) Digestibility of protein and bioavailability of amino acids in foods: effects of protein quality assessment. Wld Rev Nutr Diet 54: 26–70
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This paper was presented in part at the 71st annual FASAB meeting, Washington, DC, March 29–April 2, 1987.
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Sarwar, G., Peace, R.W., Botting, H.G. et al. Relationship between amino acid scores and protein quality indices based on rat growth. Plant Food Hum Nutr 39, 33–44 (1989). https://doi.org/10.1007/BF01092399
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DOI: https://doi.org/10.1007/BF01092399