USO DE LA EXTRUSIÓN PARA EL MEJORAMIENTO DE LAS PROPIEDADES NUTRACÉUTICAS DE MEZCLAS PLÁTANOLENTEJA

Abstract

The aim of this work was to obtain and characterize extruded of lentil/banana unripe flours, to develop a nutraceutical product with acceptable functional characteristics and high proportion of non-digestible components as dietary fiber and resistant starch, both consider as components that may help control diseases like diabetes, high blood cholesterol and colon cancer. The extrusion of flours was performed in a single screw extruder (CICATA-IPN, Mexico City, Mexico) using three process variables which were temperature from 145 to 175 ° C, moisture 20-24% and different proportions of flours ( 79.5/20.5 20.5/79.5 lentil / banana flours respectively). Once obtained the extrudates was assessed functional characterization (density, color, viscosity, differential scanning calorimetry), structural (X-ray diffraction and scanning electron microscopy) and nutritional (determination of total starch and resistant starch). The effects of process variables were analyzed using a central composite design with six replicates at the center point (Desig Expert V 5.0.4). The results were processed by response surface methodology. The mathematical models obtained indicated that the independent variables that had the greatest effect were the proportion of flour, as well as extrusion temperature and moisture content. While the ISA (solubility index of water) was mainly affected by the concentration and temperature of flour used in the extrusion process, the RS content in the extrudates was affected by proportions of flours, moisture content and temperature. The product extruded with 20% moisture, 145°C and lentil/banana flours 20.50/79.5 was the best product taking into consideration the density (0.17 g / L), water solubility index (24.78 g/100 g sample b.s.) and resistant starch (2.4 g / 100 g sample b.s.). X-ray diffraction and scanning electron microscopy showed that extrusion could modify the initial structure of the starch granules present in banana unripe flour as well as the structure of proteins that are part of the lentil. In assessing the effect of this food extruded in experimental animals fed a hypercholesterolemic diet we observed a decrease of 31.95% of glucose and 23.81% of cholesterol, therefore we recommend this product as a functional food