Quality changes in the storage of vegetable peas (Pisum sativum L.). 2. Nutritional physiologic quality

Abstract

In tests extending over several years the typical changes in the nutritional quality as occur during storage at defined temperatures (0 ... 18 degrees C) were determined in dependence on the duration of storage (chi in days). Due to the nutrient transfer from the pods to the seeds, a temporary major rise of the dry matter content (DM) is recorded in the latter together with a strongly inhibited reduction of the mono- and disaccharide content. Green peas stored without pods show a linear decrease in the DM content, degressively increasing DM losses and a more distinct reduction of saccharides. When stored with the pods, the typical decline of the vitamin C (ascorbic acid + dehydroascorbic acid) [changes in the content according to the equation y = alpha 0 + beta 1e-c theta chi and losses according to y = beta 1(1 - e-c theta chi)] goes back, mainly owing to an essentially lower coefficient for c theta. In addition, there are smaller losses in the total carotene content of such crops in the first stage of storage (losses of y = beta 1 chi 2). When storing peas without pods, we observe a a faster accumulation of the titratable total acid (up to 160%). The greatest influence on range and degree of the changes in the chemical constituents is exerted by the storage temperature. The form of the harvested crop, varietal characteristics and annual growing conditions have less bearing. Relationships and physiological causes are discussed.