Influence of Storage on Darkening and Hardening of Slow- and Regular-Darkening Carioca Bean (Phaseolus vulgaris L.) Genotypes

Abstract

New carioca bean cultivars are being introduced into the market necessitating their evaluation under trade conditions, which often require storage under ambient conditions. We therefore evaluated the darkening and hardening processes of six carioca bean genotypes each representing regular and slow darkening trait during storage under ambient conditions for five months to elucidate their relationship as a breeding strategy. Storage time adversely affected color characteristics (L*, a*, b*, C* and ΔE) depending on bean genotype, whereas hardness and resistance to cooking increased during storage independent of the lignification process. Bean darkening and hardening occurred during storage at different intensities in each genotype and were not always correlated. BRSMG-Madrepé rola, a slow darkening genotype, was unaffected (resistant to storage conditions), whereas BRS-Pontal with regular tegument darkening, was highly susceptible to storage conditions reflected in extended cooking time and darkening (low L* values). Principal component and cluster analyses on 8 constituents analyzed in this study demonstrate the difference in color characteristics, cooking time and hardness as major factors in segregating the bean genotypes. Seed coat color is an important but inappropriate single parameter for predicting the resistance to cooking or hardness induced by storage of carioca beans under ambient conditions. Development of carioca bean genotypes resistant to storage conditions is essential in reducing food losses during postharvest.

Genetic Control of Seed Coat Darkening in Common Bean Cultivars from Three Market Classes

“…These temperature and relative humidity conditions did not affect the mean scores for darkening, since there was not a significant effect of environments in the joint analyses. In addition, unlike previous reports on an effect from environment and genotype ´ environment interaction (Silva et al, 2008;Silva et al, 2014;Siqueira et al, 2014;Alvares et al, 2016), in this study, the line ´ environment interaction was not significant, showing that the response of the lines coincided in the environments. This may be explained by the fact that the trials performed in this study were conducted under greenhouse conditions, in which environmental conditions are majority controlled.…”

Chemical Changes in Bean Grains During Storage in Controlled Conditions

“…SIQUEIRA et al (2014) studied the cooking time of BRS Estilo, BRS Madreperola and BRS Pontal genotypes and recorded times of 18, 19 and 22 minutes, respectively. For the first storage periods, the cooking time values were similar to those found by the authors.…”

A New Slow‐Darkening Pinto Bean with Improved Agronomic Performance: Registration of ‘ND‐Palomino’

“…Similarly, prolonged exposure of ready‐to‐harvest mature beans in the field to temperature extremes, high humidity, and sunlight, as often results from rain‐induced harvest delays, accelerates seed darkening (Rojas‐Cifuentes et al, 2005). The problem was initially referred to as postharvest darkening, aging, or oxidizing, and in addition to pinto bean, it adversely affects many other dry bean market classes of economic importance such as cranberry, carioca, pink, and light red kidney, among others (Singh, 2006; Siqueira et al, 2014; Chen et al, 2015).…”

“…Flavonoid, proanthocyanidin, and total phenol content tend to be much higher in darker genotypes. However, genotypes show variation for seed darkening independent of phenolic content (Rojas‐Cifuentes et al, 2005; Siqueira et al, 2014). Seed darkening in lighter genotypes seem to be mostly due to polyphenoloxidase activity, whereas in dark ones, there is a combination of enzymatic and nonenzymatic oxidation (Siqueira et al, 2016).…”