Iron bioavailability in suckling and weanling rats fed a powder or in-bottle-sterilized infant formula.

Objective: The Maillard reaction and lactose isomerization may be induced during the manufacture of infant formulas. We studied the effects of dehydration and sterilization on iron bioavailability from an infant formula in suckling and weanling rats. Methods: In experiment 1, a previously reconstituted powdered infant formula and an in-bottle-sterilized liquid infant formula from the same manufacturer were fed from drinking bottles to 2-wk-old suckling rat pups for 7 d. In experiment 2, the same formulas were complemented with AIN-76 and fed to weanling rats for 7 d after a 4-d adaptation period. In both experiments, intake, body weight, and fecal and urinary excretions were monitored, and the following iron indexes were calculated: apparent absorption and retention and the coefficients percentage of absorption versus intake, percentage of retention versus absorption, and percentage of retention versus intake. Results: The liquid infant formula resulted in lower body weights on day 4, particularly among the younger rats that had significantly lower food intakes (P = 0.045). In weanling rats fed powdered and liquid infant formulas, food intake and body weight were not significantly different. The pups showed significantly higher absorption (percentage of absorption versus intake) and retention (percentages of retention versus absorption and retention versus intake) efficiencies than did the weanling rats (P < 0.001 for the three indexes). Hemoglobin values (P = 0.001) and liver iron concentrations (P = 0.009) were significantly higher in the weanling rats than in the pups. In contrast, erythrocyte iron concentrations and hematocrit were higher in the pups (P = 0.016 and 0.053, respectively). Conclusions: In rat pups, iron bioavailability is negatively affected by the consumption of in-bottle-sterilized infant formula, possibly as the result of the content of Maillard reaction products, altered proteins, and lactulose. However, when this formula is included in a mixed diet and given to weanling rats, this detrimental effect no longer occurs.

Bibliographic Details

Main Authors:	Beatriz Sarriá, M. Pilar Vaquero
Format:	Artículo biblioteca
Language:	English
Published:	Elsevier 2004-09
Subjects:	Iron, Maillard, Bioavailability, Infant formula, Food processing, Ensure healthy lives and promote well-being for all at all ages,
Online Access:	http://hdl.handle.net/10261/346253 https://doi.org/10.1016/j.nut.2004.05.002
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