Revista de Nutrição
versão On-line ISSN 1678-9865
OLIVEIRA, Admar Costa de et al. Increasing quantities of phytic acid in the diet did not affect casein digestibility and weight gain in rats. Rev. Nutr. [online]. 2003, vol.16, n.2, pp. 211-217. ISSN 1678-9865. http://dx.doi.org/10.1590/S1415-52732003000200008.
The recent increasing consumption of vegetal origin foods, in order to obtain protein or fiber sources with low fat, has led to the presence of various amounts of phytic acid in the diet. The phytic acid has a strong negative charge and is capable of interacting with divalent minerals, protein and starch, reducing their bioavailability. In the present study, increasing quantities of phytic acid were added to the purified diet AIN-93G, more specifically 0 (Control), 218, 436, 872 and 1744 mg/kg of diet, which correspond (except the control diet) to the concentration of 14.7mg of phytic of acid/g of raw bean, found in the common bean (Phaseolus vulgaris, cultivar. IAC-Carioca), representing a one to eightfold increase, respectively. Thirty-six weaning Wistar rats were fed, during an experimental period of ten days, the purified diet AIN-93G without phytic acid (Control) and the experimental diets containing the cited amounts of phytic acid per kg of diet (six rats per group). The Weight Gain, the Diet Efficiency Ratio and the Protein Quality Indexes Net Protein Ratio, Apparent Digestibility and True Digestibility were determined and showed no statistical difference (p>0.05). The mean values among the groups were: Weight Gain: 59.5 ± 5.0g; Diet Efficiency Ratio: 0.39 ± 0.01; Net Protein Ratio: 3.64 ±0.12; Apparent Digestibility: 92.7 ±1.1% and True Digestibility: 94.4 ±0.9%. Thus, the results showed that phytic acid did not affect the nutritive value of casein.
Palavras-chave : phytic acid; caseins; nutritive value; common-bean; rats.