Effect of freezing and canning on the content of selected vitamins and pigments in seeds of two grass pea (Lathyrus sativus L.) cultivars at the not fully mature stage.

Abstract

Seeds of the grass pea (Lathyrus sativus L.) cultivars Derek and Krab, with a dry matter content of about 33%, were used for freezing and for canning. The content of vitamins C, B1, and B2 and of carotenoids, beta-carotene, and chlorophylls was determined in raw and blanched material, in frozen products after 6-month storage before and after cooking to consumption consistency, and in canned products after 6-month storage. In comparison with the cultivar Krab, raw seeds of Derek contained 45% more vitamin C, 14% more total chlorophylls, 13% less thiamine (vitamin B1), and 7% less riboflavin (vitamin B2). The level of carotenoids was similar. Blanching of seeds led to a statistically significant decrease only in the content of vitamin C. Freezing and frozen storage significantly lowered the level of vitamin C and chlorophylls. The cooking of frozen seeds and the production of canned products and their storage resulted in a statistically verified reduction in the content of components analysed in all the samples. Greater losses were found in products prepared from seeds of the cv. Krab. After cooking, frozen seeds contained more of all the analysed components than the canned products.