The effects of α-lactalbumin and whey protein concentrate on α-amino acids, calcium and phosphorus levels in blood and gastrointestinal tract of rats

Abstract

The effects of two dietary proteins on α-amino acids, calcium and phosphorus concentrations in plasma, stomach and intestine were investigated in rats trained to consume, in a single two-hour daily meal, diets containing α-lactalbumin (α-la) or whey protein concentrate (WPC) for two weeks. The results indicated that the concentrations of calcium and phosphorus in the gastrointestinal tract and that of α-amino acids in portal vein were not significantly influenced by the nature of diets. The amount of α-amino acids in the gastrointestinal tract of rats fed on WPC diet was significantly (p < 0.001) higher than that of α-la group. The levels of insoluble calcium and insoluble phosphorus in the small intestine were significantly (p < 0.001) higher in α-la group than in WPC group. These results indicated that the kinetics of α-amino acids, calcium and phosphorus were differently influenced by the nature of diet ingested, the sampling time and the sites of sample collections.