Evaluation of foods protein

P. Pellett and V. R. Young, in Nutritional Evaluation of Food Protein, United Nations University, 1980. 

Adoption of PDCAAS allows evaluation of food protein quality based on the needs of humans. Isolated soy protein such as Solae , with a PDCAAS of 1.0, is a complete protein and has the same score as milk protein and egg white. 

Current systems for the evaluation of food protein for ruminant animals involve determinations of the degradabUity of protein in the rumen, the synthesis of microbial protein, the digestion in the lower gut of both food and microbial proteins, and the efficiency of utilisation of absorbed amino adds. The methods used to determine these components of the system are described next, after which their use in the systems will be illustrated. 

Gu, C., Majumder, K., and Wu, J. (2011). QSAR-aided in siUco approach in evaluation of food proteins as precursors of ACE inhibitory peptides. Food Res Int 44, 2465-2474. 

Hinton, D.M., US FDA Redbook II immunotoxicity testing guidelines and research in immunotoxicity evaluations of food chemicals and new food proteins, Toxicol. Pathol., 28, 467, 2000. 

Most materials of interest as ingredients are neither completely soluble nor completely insoluble, and most foods are water swollen systems. The concept of uptake of water or swelling may, therefore, provide valuable information for evaluation of a protein as a food ingredient. Swelling was defined by Hermansson (2 ) as... 

Faster and finer approaches for the analysis of food proteins are necessary for the assurance of food quality and safety (106). Generally, the most recent applications of microchip electrophoresis for the analysis of proteins or peptide biomarkers in foods include the characterization of protein extracts (107), the detection of high-quality value products adulterated with products of inferior quality (108), and the evaluation of the quality due to food storage or different technological process (109). 

This chapter sets out the role and importance of protein in human health, human protein requirements, and the measurement of food protein quality. Specifically, focus is given to the need to improve sorghum protein quality and the developments that have already taken place in this area are reviewed. Lastly, the improvements in sorghum protein quality achieved to date in the Biosorghum project are presented and on the basis of these data, the potential of biofortified sorghum to improve children s nutritional status is evaluated. 

Several methods have been described for the production, characterization and evaluation of milk protein hydrolysates tailored for specific applications in the health-care, pharmaceutical, baby food and consumer product areas (see Fox and Mulvihill, 1992, for references). 

The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is superior to other methods for evaluating the protein quality of food proteins for humans because it measures the quality of a protein based on the amino acid requirements of a 2-5 year old child (the most demanding age group), adjusted for digestibility [120]. It has replaced the Protein Evaluation Ratio (PER). 

All protein determination methods described are not absolute and demand some form of calibration. The Kjeldahl s method remains the only official method currently available for calibration purposes and maintains its position as the most frequently used technique for the determination of organic nitrogen in food products. CE and immunochemical (enzyme-linked immunosorbent assay) techniques are most suitable for rapid separation and quantification of individual food proteins and are promising for widespread use in food protein analysis due to their high sensitivity, specificity, and simplicity of operation. There are numerous methods for the evaluation of the nutritional quality of food proteins. 

Liveweight gains may not be related to protein stored, and a more accurate evaluation of a protein may be obtained by using the results of nitrogen balance experiments. In such experiments, the nitrogen consumed in the food is measured,... 

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