The determination of the biological value of dietary proteins, XVI. The Minimum Protein Requirement of Humans, tested with Mixtures of Whole Egg plus Potato and Maize plus Beans

Abstract

1. Long term dietary experiments were made with adult males, using a single protein source and mixtures of two protein sources. The mixtures used were: whole egg plus potato and, for comparison, the mixtures of egg amino acids plus potato amino acids. In addition a mixture of beans and maize was tested. 2. The minimal requirement for a protein source was taken as the amount of protein required when equilibration of intake and output had been achieved. 3. The biological value of a protein source was defined as the reciprocal of the minimum protein requirement. The biological value of whole egg protein was set equal to 100. 4. It was found that the minimal protein requirement was less for a mixture of the two protein sources than for the individual sources. Zusammenfassung: Zur biologischen Wertigkeit von Nahrungsproteinen, XVI: Der Protein-Minimalbedarf des Menschen, untersucht an Vollei plus Kartoffeln und Mais plus Bohnen. 1. Mit erwachsenen Männern wurden Langzeit-Diät-Versuche durchgeführt. Dabei wurden sowohl einzelne Proteinquellen als auch Mischungen aus zwei Proteinquellen verwendet, und zwar Vollei plus Kartoffeln und zum Vergleich Mischungen von entsprechenden Aminosäuregemischen. Außerdem wurden noch Mischungen aus Bohnen und Mais getestet.5. Although the actual requirement for a particular protein source varied between test subjects, the optimal ratio of mixtures, i. e. that for which there was the lowest requirement, was the same for each subject. 6. The optimal mixture of whole egg plus potato had a biological value 36% greater than whole egg alone. When we tested amino acid mixtures, simulating egg plus potato, the biological value of the optimal mixture was 31 % greater than that of egg alone. 7. The optimal mixture of maize plus beans had a biological value equal to that of whole egg alone, in spite of the fact that the biological values of the single components were about 28 % lower. 8. Application of these results in practice are described.

3‐Hydroxy‐3‐methylglutaryl‐coenzyme A lyase deficiency: A review

“…He has been allowed to follow a selfregulated diet which consists of a massive intake of potatoes and citrus cordials and little else. He appears to have chosen wisely in selecting potatoes as his basic food since the potato is rich in complex carbohydrate and relatively poor in fat and protein, though the protein that is present is of high biological value (Kofranyi et al, 1970). The child has been labelled hyperactive because he is inattentive at school and he has a need for special teaching.…”

Composition of foods and dishes commonly consumed in villages of the Gezira area of Sudan ii. Amino acids and protein quality

“…These methods have severe limitations which are discussed by Kofrany and Jekat (1964). The most accurate method to evaluate the quality of a protein is that of biological testing of nitrogen utilisation in human subjects (Kofrany, Jekat and Müller-Wecker, 1970;WHO, 1985). This approach is methodically extremely complicated and can be performed only under limited conditions.…”

Amino Acid Tablet-Substituted Diets in the Management of Chronic Renal Failure

“…If, as is indicated by some studies, the essential amino acid requirements are less, there is no advantage in supplying more essential nitrogen than required. Preferably, any latitude so provided would best be directed towards a more appropriate nonessential nitrogen supply in the dietary protein constituents as suggested by the work of Kofranyi et al (1970). Schloerb (1966) studied the value of amino acid tablets in chronic renal failure patients.…”

“…Shaw et al (1965) and Hyne et al (1972) have recommended that a high proportion of high biological value protein should be used whereas Ford et al (1969) have suggested that the biological value of the protein is of little impor tance. However, recent work by Kofranyi et al (1970) may lead to further revision of the type of protein used in the design of these diets. They showed that a mixture of first and second class proteins could give a better nitrogen utilization than a first class protein alone.…”