Anthocyanidin Pigments of Southern Peas, Vigna sinensis

Southern peas are an important vegetable crop in the Southeastern states. They constitute 11 percent of the total vegetables packed in this area and are exceeded in volume only by green beans and tomatoes (39).

Southern peas are not widely distributed by retailers throughout the United States. Discoloration during processing is believed to be the major reason preventing wide distribution (13). Also, color is a major factor of quality grade, and deterioration of color in these products results in considerable economic loss to the processor.

With respect to freezing of southern peas, the discoloration occurs during blanching. The water soluble pigments are gradually transferred from the peas to the blanch water. The dissolved pigment adheres to the precipitated solids of the blanch water, and upon sufficient accumulation, the colored solids collect on the surface of the peas.

With these factors in mind, this study was made in an attempt to: (1) determine effects of different blanch water additives on the quality of the product, (2) elucidate the nature of the coloring compounds of southern peas, and (3) study the causitive agents of discoloration in southern peas.