Effects of Cutting and Blanching on the Chlorophyll and Ascorbic Acid Contents in Some Vegetables

Abstract

　In this study, we examined the effects of blanching (hot water or steam treatment) on the chlorophyll and ascorbic acid contents in 5 types of vegetables: spinach (Spinacia oleracea L.), komatsu-na (Brassica campestris var. pervirlidis), garden pea (Pisum sativum L.), haricot bean (Phaseolus vulgaris L.), and broccoli (Brassica oleracea var. botrytis). The optimum blanching time for the 5 different test samples was found to be 2 min. with hot water and 5 min. with steam. The chlorophyll content in all the test samples was almost the same after the 2 different blanching treatments. However, the ascorbic acid content decreased in all the samples after the blanching treatments, and the rate of decrease was higher with hot water treatment than with steam treatment. The ascorbic acid content in spinach decreased after the blanching treatments at different times of the year and was higher in winter than in summer. Cutting before the blanching treatments was found to accelerate the reduction in ascorbic acid content in all the test samples.