A comparative study among landraces of Phaseolus vulgaris L. and P. coccineus L. based on molecular, physicochemical and sensory analysis for authenticity purposes

The common and runner beans are the two most widely cultivated species because of their highly nutritive value for humans and animals. This study was undertaken to interpret data from physicochemical, sensory and molecular (DNA) analyses toward evaluating, characterizing and separating 5 common bean (Phaseolus vulgaris) and 5 runner bean (Phaseolus coccineus) landraces, cultivated under organic growing conditions. Furthermore, an attempt was made to determine patterns and interrelationships among the quality traits and sensory characteristics to get a better insight into the most effective discrimination between common and runner bean landraces, by means of multivariate analysis (Principal Component Analysis and Discriminant Analysis). In this study an accurate and effective discrimination of bean cultivars and Phaseolus species was possible using different methodologies. PCA was found to be the most informative either by using exclusively physicochemical data (92% of variability) or in conjunction with sensory data (99.4% of variability). P. vulgaris is characterized by 6 parameters (intensity, juiciness, sweetness, brightness, bitterness and consistency) whereas P. coccineus by odor, tenderness and metallic taste. Molecular analysis (MA) proved to be a fast and informative method only for discrimination of the Phaseolus species whereas (DA) highlighted the most important characteristics per cultivar and species. (C) 2012 Elsevier B.V. All rights reserved