Effect of Temperature, Relative Humidity, and Light on the Color of ‘California Light Red Kidney’ Bean Seed during Storage1

Abstract

Seed of Phaseolus vulgaris L. cv. California Light Red Kidney was stored at 1, 12, and 24°C and 30 and 80% relative humidity for 1 year. The higher temperatures accelerated darkening of seed coat color. High relative humidity at 24° resulted in the darkest colored beans, a complete loss of germination, a 4-fold increase in fat acidity and a nearly 2-fold increase in the time required to cook until tender when compared with beans stored at 1° and 30% relative humidity. Beans stored at 1° and 30% relative humidity very nearly retained their original color, germination percentage, and fat acidity in addition to retainment of their cooking time requirements. Ultraviolet and cool-white light also darkened beans in storage, but in contrast to the darkening caused by high humidity and temperature, light promoted darkening was not associated with loss in quality factors.