Effect of Different Cooking Method on Vitamin E and K Content and True Retention of Legumes and Vegetables Commonly Consumed in Korea

This study investigated the effect of cooking method on the content and true retention of vitamin E and K in legumes and vegetables, which are commonly consumed in Korea. Among eight isomers of vitamin E, α- and γ-tocopherol were detected at 0.44–1.03 and 2.05–2.11 mg/100 g, respectively, in legumes including chick pea, kidney bean, lentil, pea, and sword bean and they were decreased after boiling. Phylloquinone (vitamin K 1 ) was present at a range of 31.33 to 91.34 μg/100 g in legumes and true retention was reduced after boiling. In 21 kinds of vegetables, α-tocopherol and phylloquinone were present at 0.14–1.85 mg/100 g and 34.55–510.83 μg/100 g, respectively. α-Tocopherol and phylloquinone increased in most vegetables after cooking via blanching, boiling, steaming, and grilling. This study revealed that cooking changed vitamin E and K contents of legumes and vegetables and the changes were dependent on the type of food and cooking method.