Relationship of aging to the shelling and quality of Southern peas, Vigna sinensis

Food processors in Tennessee pack over half of the 50 million pounds of Southern peas processed in the Southeastern states each year. These peas account for almost 11 per cent of the total vegetables packed in the Southeastern states and are exceeded in volume only by green beans and tomatoes. Over two-thirds of the Southern peas are packed in the green pea stage of maturity (27). To be processed in the green pea stage, Southern peas are harvested by hand and hauled to the processor by truck. A major problem at this stage of handling, however, is that the peas that have been picked only a few hours do not shell easily enough to permit mechanical shelling. Processors have found that mechanical hullers can be used if the peas are allowed to age for 24 or more hours. Aging is easily accomplished by either leaving the peas on trucks or loading them onto large wagons furnished by the processor. During the aging period, heat from respiration of the peas and bacterial action causes the product temperature to increase several degrees above the ambient temperature (24). Due to the excessively high temperatures and prolonged storage period usually encountered during this aging period, there is a high degree of probability that the quality of the peas is affected considerably. Furthermore, the storage of over 100 tons of peas for 24 hours presents economic and logistic problems. Also more and more economic pressure is being applied on the food industry to convert to continuous flow operations. However, until some means of effecting increased shellout percentages of freshly harvested peas is evolved, continuous flow of Southern peas from field to package cannot be realized. With these factors in mind, this study was made in an attempt to: (1) determine if aging exerts any influence on percentage shellout. (2) study the effect of aging on certain specific quality factors. (3) study certain morphological changes of the Southern pea pod.