Evaluation of Protein in Foods. X. A Comparison of Methods for Assessing the Protein Contribution of Five Middle Eastern Meals

Protein quality of five Middle Eastern meals was evaluated by using simplified chemical score (SCS), protein efficiency ratio (PER), net protein ratio (NPR), protein retention efficiency (PRE), and net protein utilization (NPU). The meals consisted of Arabic bread in combination with sesame (Halaweh), with sesame and chickpea (Hommos tehineh), with rice and lentil (Rice Mujaddarah), with parboiled wheat and lentil (Burghul Mujaddarah), or with parboiled wheat, yoghurt, and meat (Kishk). Halaweh, Hommos tehineh, and Kishk were limiting in lysine, while the other two meals were limiting in methionine. Lysine and methionine appeared to be fully available in all meals with the exception of Halaweh, in which lysine was partially unavailable. All methods ranked the meals in the same order, with Halaweh as the poorest, Hommos tehineh the best, and the other three meals slightly inferior to Hommos tehineh in quality. Methods for determining the protein contribution of meals which took into account both quantity and quality of protein, i.e., net dietary protein calories per cent (N.D-p. Cals %), protein rating (PR), and per cent complete protein (% CP), were also tested. Values for N.D-p. Cals % and PR correlated closely with each other and relatively poorly with % CP. Values for SCS × % protein calories correlated closely with N.D-p. Cals % and PR.