Effect of Protein Level and Protein Source on Zinc Absorption in Humans

Abstract

The effect of increasing levels of various protein sources on zinc absorption from a legume-based meal was studied in humans with the use of a radionuclide technique. The meals were extrinsically labelled with 65Zn and absorption was determined from measurements of the whole-body retention of the isotope. The mean fractional zinc absorption for the 13 meals was 24.7 +/- 6.9% and was only influenced by the protein content of the meal to a limited extent (r = 0.45). However, the amount of zinc absorbed from the meals was strongly correlated with both the protein (r = 0.85) and zinc content (r = 0.86): 5.9 +/- 1.7 mumol of zinc was absorbed from the basal bean meal which had the lowest protein content; the addition of low zinc chicken doubled the protein content and increased zinc absorption to 10.3 +/- 2.0 mumol; the addition of zinc-rich beef also doubled the protein content, however, zinc absorption was increased to 15.9 +/- 4.7 mumol. It is concluded that the zinc content of the main protein source of the diet determines the amount of zinc absorbed to a large extent. However, relatively small amounts of animal protein can significantly improve the value of a legume-based meal as a source of zinc.

Comparative Evaluation of the Amino Acid Profile of the Brain and Eyes of Guinea Fowl (Numida meleagris) Hen

“…The percentage of Cys in TSAA had been set at 50 % in rat, chick and pig diets [32]. Cys can spare with Met in improving protein quality and has positive effects on mineral absorption, particularly zinc [33,34]. Table 3 shows the AA scores (AAS) of the samples based on whole hen's egg profile [8].…”

Composition, mineral safety index, calcium, zinc and phytate interrelationships in four fast-foods consumed in Nigeria

“…The percent Cys in TSAA in ripe coconut endosperm was 62.9 [39]. Information on the agronomic advantages of increasing the concentration of sulphur-containing amino acids in staple foods shows that Cys has positive effects on mineral absorption, particularly Zn [42,43]. Table 8 contains the EAA scores of the fast-foods.…”

Avaliação da solubilidade de cobre e zinco em caldos de leguminosas

“…A existência de quelados dos elementos traço permite uma eficiência de absorção destes elementos em até 100%. O conhecimento da forma quími-ca dos elementos traços é essencial para definir a biodisponibilidade dos mesmos [2,4,6,8,9,11,14].…”