Discriminação da qualidade de genótipos de trigo produzidos no Rio Grande do Sul e sua utilização na forma de grãos cozidos para a alimentação humana

Abstract

Wheat is a widely distributed and consumed cereal in the world mainly due to its energetic and nutritional function for human health. In search of adaptations to edaphoclimatic conditions, as well as market requirements, genetic improvement has focused its efforts on obtaining genotypes suitable for wheat production in Brazil. Although the genetic modification has advanced significantly, the growing location is a crucial factor for the final quality of the wheat. Thus, the objective of this study was to evaluate and characterize the quality of thirteen genotypes indicated for cultivation in the state of Rio Grande do Sul, and to investigate the quality of these grains for consumption as cooked grains. The grains were cultivated in the municipalities of Cachoeira do Sul (CDS), Santo Augusto (STA), São Gabriel (SAG), and Vacaria (VAC). The following genotypes were evaluated: Ametista, BRS 331, BRS Parrudo, CD 1303, FPS Certero, Marfim, ORS Vintecinco, TBIO Iguaçu, TBIO Mestre, TBIO Sintonia, TBIO Sinuelo, TBIO Sossego, and TBIO Toruk. The environmental conditions of VAC provided a significant increase in the protein content for all studied genotypes, consequently these grains had the lowest total starch contents. Both the physical-chemical attributes and the technological properties of wheat have been shown to be extremely influenced by the growing environment. The multivariate analysis of the data was efficient to discriminate the quality of the genotypes in each of the localities, as well as to indicate the dependent variables that most influenced this differentiation. Among the four growing locations, the parameters final viscosity, gluten strength, falling number and extensibility were responsible for explaining the quality differences between the genotypes. The STA location exhibited the highest discriminant power over the evaluated genotypes, and therefore the STA samples were chosen for quality evaluations of the cooked grains. The thirteen genotypes evaluated varied significantly regarding the cooking quality. The cooking time and hardness of the grains were affected by several factors, including starch, amylose, protein and fiber content, as well as the test weight and the thousand grains weight. The genotypes expressed different behaviors in the digestibility analysis and were subdivided into two groups: those with less than 60% of starch hydrolysis and those with a digestibility higher than 70%. The obtained results may help the wheat industries to segregate wheat cultivars based on market opportunities, especially those related to whole wheat products and to the especial requirements of starch digestibility.