Fósforo fítico y actividad de fitasa en fórmulas infantiles basadas en cereales

El ácido fítico es un ácido orgánico presente en granos de cereales. El fósforo contenido en su molécula (PFi) no es absorbible por una baja solubilidad, aunque su biodisponibilidad puede incrementarse por la actividad de enzimas fitasas (AFi). Con el objetivo de cuantificar el contenido de PFi y AFi en suplementos elaborados a partir de cereales y destinados a infantes lactantes, se seleccionaron cinco fórmulas de amplia distribución en mercados locales,identificadas de acuerdo a los cereales base de su composición como: A (arroz), T (trigo), ATS (arroz, trigo y aislado de soya), ATM (arroz, trigo y maíz) y ATMS (arroz, trigo, maíz y aislado de soya). Se tomaron cinco muestras por fórmula, cada una correspondiente a un envase (400 a 500 g) elaborado en lotes diferentes y con fecha de vencimiento posterior al muestreo. La proteína cruda varió de 16,8 a 7,2%, con el mayor valor para ATS, y los menores para T y ATM (P< 0,01). El extracto etéreo mostró un rango de 0,31 a 0,75%, mientras la relación calcio:fósforo entre 1,6 en ATM y 1,1 para el resto. El PFi representó el 61,5% del fósforo total en T, con diferencias (P< 0,01) respecto al resto (39,9 ± 6,8%). Sólo se detectó AFi en ATM, T y ATS (570, 300 y 152 U/kg, respectivamente). Se concluye que la composición química se ajustó a lo reportado por los fabricantes, con un elevado contenido de PFi y una AFi fundamentalmente asociados a la presencia de trigo en las fórmulas.

Phytic phosphorus and phytase activity in cerealbased infant formulas. Phytic acid is an organic acid present in cereal grains. The phosphorus inside its molecule (PPhy) is not available because of its low solubility, though the bioavailability could be increased by the activity of phytase enzymes (PhyA). With the purpose of quantifying the PPhy and PhyA in supplements manufactured from cereals and intended for lactating infants, five formulas of wide distribution in local markets were selected and identified depending on the main vegetable ingredients as A (rice), T (wheat), ATS (rice, wheat and soy isolate), ATM (rice, wheat and maize) and ATMS (rice, wheat, maize and soy isolate). Five samples were taken from each formula, each one corresponded to a commercial brand (400 to 500 g), coming from different batches and before their expiration date. The crude protein ranged from 7.2 to 16.8%, with de highest value for ATS and the lowest for T and ATM (P< 0.01). Ether extract varied from 0.31 to 0.75%, while the calcium: phosphorus ratio from 1.6 for ATM, to 1.1 for the rest. The PPhy was 61.5% of the total phosphorus in T, with differences (P<0.01) compared to the other formulas (39.9 ± 6.8%).PhyA was only detected in ATS, T and ATM (152,300 and 570 U/kg, respectively). The chemical composition complied with the manufacturer report, with a high content of PPhy and PhyA associated to the wheat presence in the formula.

[Phytic phosphorus and phytase activity in cereal-based infant formulas]. / Fósforo fítico y actividad de fitasa en fórmulas infantiles basadas en cereales.

Phytic acid is an organic acid present in cereal grains. The phosphorus inside its molecule (PPhy) is not available because of its low solubility, though the bioavailability could be increased by the activity of phytase enzymes (PhyA). With the purpose of quantifying the PPhy and PhyA in supplements manufactured from cereals and intended for lactating infants, five formulas of wide distribution in local markets were selected and identified depending on the main vegetable ingredients as A (rice), T (wheat), ATS (rice, wheat and soy isolate), ATM (rice, wheat and maize) and ATMS (rice, wheat, maize and soy isolate). Five samples were taken from each formula, each one corresponded to a commercial brand (400 to 500 g), coming from different batches and before their expiration date. The crude protein ranged from 7.2 to 16.8%, with de highest value for ATS and the lowest for T and ATM (P < 0.01). Ether extract varied from 0.31 to 0.75%, while the calcium: phosphorus ratio from 1.6 for ATM, to 1.1 for the rest. The PPhy was 61.5% of the total phosphorus in T, with differences (P < 0.01) compared to the other formulas (39.9 +/- 6.8%). PhyA was only detected in ATS, T and ATM (152, 300 and 570 U/kg, respectively). The chemical composition complied with the manufacturer report, with a high content of PPhy and PhyA associated to the wheat presence in the formula.