Desenvolvimento de arroz integral de cozimento rápido: propriedades físico-químicas, tecnológicas e digestibilidade do amido

Abstract

In recent years there has been an exponential increase in the consumption of instant foods, especially in the developed countries, where the consumers who are most looking for this type of food are. In line with this trend of food consumption is instant rice, which is also known as Quick Cooking Rice (QCR), or simply "instant rice." In this study, the production of instant rice followed the following stages: hydration, cooking, pre-treatment and drying. The conditions of each stage for each genotype should be adequately studied and selected, aiming at high quality of the final product. In the present study, three cooking temperatures (72, 80 and 88°C) were tested in the production of quick-cooking brown rice using two rice genotypes (Puitá Inta CL and INOV CL). The following variables were analyzed: cooking time, color, scanning electron microscopy (SEM), percentage of damaged grains, moist weight and volume during cooking, content and rate of amylose release, protein extraction content and capacity, differential calorimetry of scanning (DSC), X-ray diffraction (XRD), visco-amylographic properties, sensory properties and in vitro digestibility of starch. The cooking time of brown rice, without application of the treatment to elaborate QCR, ranged from 23.0 to 23.6 min. When the cooking was conducted at 88°C, the cooking time was reduced to 5.5 to 6.9min, depending on the genotype. The highest grain deformation was observed in the treatments of Puitá Inta CL. The XRD analysis showed higher gelatinization capacity at the cooking temperature of 88°C of Puitá Inta CL brown rice. The appearance, texture, and taste of cooked rice at 88 ° C, prepared quickly, did not differ statistically from its brown rice counterparts that did not undergo the QCR process. Starch digestibility was reduced by about 20-22% for ready-cooked brown rice prepared at 88°C. The lowest in vitro digestibility of starch was observed for the INOV CL genotype cooked at 88°C, this effect being related to the structural integrity of the grain, that is, grains that did not have a rupture and exposure of the endosperm.