Bento Juliana Aparecida Correia, Lanna Anna Cristina, Bassinello Priscila Zaczuk, Oomah B Dave, Pimenta Maria Eunice Bertelli, Carvalho Rosangela Nunes, Moreira Alécio Souza
School of Agronomy, Federal University of Goiás - UFG, PO Box 131, ZIP 74690-900, Goiânia, Goiás, Brazil.
Embrapa Rice and Beans, PO Box 179, ZIP 75375-000, Santo Antônio de Goiás, Goiás, Brazil.
Food Res Int. 2020 Aug;134:109249. doi: 10.1016/j.foodres.2020.109249. Epub 2020 Apr 18.
High temperature, moisture content and radiation conditions, common in the tropics, accelerate the physiological post-harvest disorders in beans, affect integument color and bean hardness. This study explored the darkening and hardening mechanisms in carioca type beans during storage. The contrasting genotypes for bean darkening and hardening (BRS Estilo and BRS Pontal: rapid darkening and hardening; BRSMG Madrepérola and CNFC 10467: slow darkening and partially resistant to hardening; and a Canadian genotype of the Pinto Bean type resistant to darkening (negative control)) were evaluated right after harvest and after six months storage at 20.3 ± 0.2 °C and 78.9 ± 6.0% RH, with respect to their physicochemical, biochemical and morphological attributes. All the samples hardened with time, but the velocity of darkening did not always parallel the degree of hardening of the beans (that increase linearly with time), which indicates that the color of the bean integument was not a safe indicator to predict the culinary quality of carioca beans. During storage, the SOD (superoxide dismutase) activity and LP (lipid peroxidation) in the cotyledon increased, and the increase was more significant in the integument of the rapid-darkening genotypes. The oxidative stress detected in the beans apparently started in the green bean formation phase, continuing during post-harvest, especially for the rapid-darkening beans. Quantification of the bivalent ions in the bean fractions, together with the degree of membrane damage was positively associated with bean darkening, independent of the group. Thus, aging of the carioca beans could be triggered by a complex mechanism involving diverse intrinsic factors in different degrees according to the genotype and the post-harvest period, but some parameters could serve as indicators, as cooking time, hardness and color, to differentiate between rapid and slow darkening beans.
热带地区常见的高温、湿度和辐射条件会加速豆类收获后的生理失调，影响豆荚颜色和豆子硬度。本研究探讨了卡里约卡型豆类在储存期间变黑和变硬的机制。对豆类变黑和变硬的对比基因型（BRS Estilo和BRS Pontal：快速变黑和变硬；BRSMG Madrepérola和CNFC 10467：变黑缓慢且部分抗硬化；以及一种抗变黑的加拿大平托豆型基因型（阴性对照））在收获后以及在20.3±0.2°C和78.9±6.0%相对湿度下储存六个月后，对其理化、生化和形态学属性进行了评估。所有样品都随时间变硬，但变黑速度并不总是与豆子的硬化程度平行（硬化程度随时间呈线性增加），这表明豆荚颜色不是预测卡里约卡豆烹饪品质的可靠指标。在储存期间，子叶中的超氧化物歧化酶（SOD）活性和脂质过氧化（LP）增加，在快速变黑基因型的豆荚中增加更为显著。豆类中检测到的氧化应激显然始于绿豆形成阶段，在收获后持续存在，尤其是对于快速变黑的豆子。对豆类各部分中二价离子的定量以及膜损伤程度与豆类变黑呈正相关，与组别无关。因此，卡里约卡豆的老化可能由一种复杂机制引发，该机制根据基因型和收获后时期不同程度地涉及多种内在因素，但一些参数，如烹饪时间、硬度和颜色，可以作为区分快速和缓慢变黑豆类的指标。
