Differences in Distribution and Levels of Four Calcium Components among Different Organs of Chinese Cabbage (Brassica rapa) and Cabbage (B. oleracea)

Abstract

Different organs of chinese cabbage and cabbage were analyzed for four calcium (Ca) components, water−, 1N NaCl−, 2% acetic acid− and 5% HCl−soluble Ca. Among these forms of Ca, water-soluble Ca is highly degestible by humans. In Chinese cabbage and cabbage, the outer leaves had the highest concentration of total and water-soluble Ca, compared to head-formed leaves and stem. Head-formed leaves of these vegetables had lower concentrations of water-soluble Ca than turnip rape. However, total and water-soluble Ca concentrations in the outer leaves of cabbage were 1.84 mg・g −1 FW and 1.26 mg・g −1 FW, which were 2.1, 2.9-fold greater than those in turnip rape, respectively. Furthermore, the outer leaves of Chinese cabbage had the same concentrations of total and water-soluble Ca as turnip rape. These findings suggest that the outer leaves of Chinese cabbage and cabbage are useful materials for juice and other new products.