Características agronômicas, nutricionais e tecnológicas de grãos de feijão carioca armazenados, cultivados em sistemas orgânico e convencional

Abstract

The consumption of functional foods, such as beans, has brought important benefits to health, consequently, there is an increasing demand for organic products, which are considered healthier. However, due to the genetic variability of this crop, it is necessary to evaluate it in the field then determine which cultivars are most adapted to different cropping managements, as well as establish the quality attributes involved in the preservation of this leguminous. Thus, this trial aimed at evaluating the agronomic characteristics of carioca beans, cropped in organic and conventional systems, indicating which cultivars are most adapted to each system as well as characterizing the cooling storage effect and in uncontrolled environmental conditions, in order to preserve nutritional and technological characteristics of these grains. Multivariate techniques were applied to determine which variables influenced most on beans quality, and to verify similarities between conservation methods and how carioca beans were produced. Eight carioca bean cultivars were sown in the organic and conventional systems, and the correlation between the production and yield components was evaluated. The studied cultivars were evaluated when freshly harvested (S); and after 180 storage days under refrigeration (R) and environmental conditions (A); according to the nutritional characteristics: protein (Ptn), calcium (Ca), iron (Fe), phosphorus (P), phytic acid (Fit), tannins, antioxidant capacity (DPPH) and technologic characteristics: grain mass (GM), water content (WC), electrical conductivity, grain color (L*, a*, b*, H * and C *) and sphericity, texture, cooking time (CT) and hydration capacity (HC). According to yield, cultivars such as Andorinha, Curió, Estilo, Emperador and Notável were more adapted to the organic cropping, while all the tested cultivars, except Curió, can be indicated to the conventional cropping. The variables that showed the highest correlation with yield were the number of pods in organic beans and plant height in the conventional ones. The cooling storage preserved the technological quality of organic beans, increased the antioxidant capacity and kept higher amount of iron in beans. It also contributed to phosphorus decrease and the significant increases of Fit and tannins, considered antinutritional factors. Campos Gerais beans is a cultivar from IAPAR that showed the best results on quality preservation after six months of storage. According to these data, the main and cluster components (APC) were analyzed. Thus, variables such as Ptn, Ca, P, Fit, tannins, DPPH, CH, TC, MG and H * influenced most beans quality, and were defined according to APC use. Based on the use of Cluster, it is possible to classify cultivars into groups and verify that the refrigerated storage was effective in maintaining their quality. In addition, this technique showed the similarity between organic and conventional beans that belonged to the same cultivar.