Fluorescence Intensity Indicates Bean Hardening

Abstract

ABSTRACTFluorescence microscopy was used to measure the intensity of fluorescent emanation from the cut surface of uncooked bean cotyledons. This parameter correlated significantly with the hardness of soaked cooked beans determined by either compression force of whole beans or the probe force of cotyledons only. This relationship existed whether hardness resulted from varietal differences or elevated storage conditions. Similarly, a significant correlation was found between the fluorescence intensity of isolated cell wall material and bean hardness. These results led to the conclusion that the increase in fluorescence intensity in hard beans may have been due to the accumulation of phenolic compounds within the cell wall and that the procedure developed had potential as a quicker and simpler way to determine bean hardness.