DETERMINACIÓN DE LA ESTABILIDAD DE ÁCIDO ASCÓRBICO Y RETINOL EN PREPARACIONES REFORZADAS CON PRODUCTOS ALIMENTICIOS FORTIFICADOS

Abstract

Introduction: Homemade meals elaboration implies vitamins losses in different cooking procedures. Using reinforced food would cover nutrient recommendations during critical periods of life. The aim of this experimental pilot study was to evaluate the variation of ascorbic acid and retinol concentrations in reinforced meals with fortified cereals and to analyze their value as a feeding strategy. Materials and Methods: These vitamins were selected as indicators of lability in three recipes with different cooking procedures prepared at home under reproducible conditions. Retinol was analysed through HPLC and Ascorbic Acid by capillary electrophoresis in one sample and HPLC in others because of detection limit of each methods. Results: According to cooking method, Retinol increased its concentration in post-cooking samples due to water evaporation (14% among enriched) or reduced it due to temperature, pH or presence of oxygen by oven or direct cooking (5% and 22% respectively). Between cooked samples, reinforced sample presented an 18% - 20% increase versus non-enriched one. Cooking by conduction (frying pan) or oven (air convection currents) generated a partial loss (13% and 24% respectively) of ascorbic acid. The loss was total in direct fire firing and higher surface/volume ratio. Cooked reinforced samples showed a 90% increase when the vitamin was preserved. Final concentration variations were related to initial concentrations and cooking methods involving different forms of heat transfer and partial pressures of O2. Conclusions: Vitamins studied were shown to be unstable in meals after domestic cooking, although their loss is partial. Therefore, reinforcing preparations with fortified food products would be a useful strategy to cover micronutrients in critical situations, in food preparations with low nutritional density and different consistencies. Keywords: Food reinforced; retinol; ascorbic acid; cooking; stability.