Analyses of Cholesterol, Retinol, beta-Carotene, and Vitamin E Contents in Regional Food of South Korea

A total of 42 regional foods of South Korea were regionally sampled (metropolitan city 8, Gangwon 8, Chungcheong 5, Gyeongsang 10, and Jeolla 11) and analyzed for their cholesterol, retinol, beta-carotene, and vitamin E contents. All applied analytical methods were verified, and analytical quality control was performed during the entire of study. The cholesterol contents (mg/100 g) of the 42 regional foods were high in the order of Jipbulgui kkomjangeo (Gyeongsang) 170.9, Moraejip twigim (Gyeongsang) 167.9, and Bungjangeo sogeum gui (Jeolla) 167.1, which indicate that 100 g intake of these foods would exceed 50% of the upper intake level per day (UL, 300 mg for adult). However, on the basis of 100 g intake, the other foods contained cholesterol contents of less than 20% of cholesterol UL. Retinol content (μg/100 g) was high in a few foods prepared mainly from animal sources such as Jipbulgui kkomjangeo (1,101.5), Bungjangeo sogeum gui (438.7), and Gomchi guk (139.0), while it was not detected in the 25 other foods. On the other hand, beta-carotene was detected in all foods except for Jipbulgui kkomjangeo, showing a range from 0~1,185.9 μg/100 g. Vitamin A content (μg retinol activity equivalent/100 g) was highest in Jipbulgui kkomjangeo (1,101.5) while Chodang sundubu (0.03) showed the lowest content. Vitamin E contents (mg alpha-tocopherol equivalent/100 g) of regional foods ranged from 0.07 (Dwaeji-gukbap)~3.05 (Bungjangeo sogeum gui), which correspond to 0.6~25.4% of the daily adequate intake amount (12 mg for adults). All analytical methods for fat-soluble components using HPLC and GC showed good accuracy (85.5~101.6% recoveries) and precision (less than 5% relative standard deviations), which met the requirements of official method validation guidelines. All verification and quality control data in this study indicate that all analytical data are reliable enough to be used for the construction of cholesterol, retinol, beta-carotene, and vitamin E databases for regional diets in Korea.