This study aimed to determine the changes in the vitamin B5 content of raw and cooked vegetables. The nineteen vegetables were subjected to different cooking methods, viz. blanching, boiling, pan-broiling, and steaming. Vitamin B5 was quantified by reversed-phase high-performance liquid chromatography (HPLC) using photodiode-array (PDA) detection (200 nm). The standard reference materials (SRM) were used to validate the accuracy of vitamin B5 measurement method used in this study. The cooking yields ranged from 82.63 to 107.62% and decreased in most of the vegetables except bitter melon, curled mallow, and eggplant. The raw kabocha squash, Danhobak, had the highest vitamin B5 content (0.671 mg/ 100 g) among the samples. All cooked vegetables showed lower vitamin B5 content compared to the raw samples. The true retention ranged from 0% (crown daisy, blanching) to 84.49% (kabocha squash, steaming). These results indicate that vitamin B5 is degraded after cooking. Pan-broiling and steaming are better cooking methods than the others for retaining vitamin B5. The true retention of vitamin B5 in the samples markedly depends on the cooking method and food matrix. These results can be used as important basic data for nutritional evaluation of meals.

This study examines the effects of different cooking methods (stir-frying, steaming, superheated-steaming) on the contents and the true retention of moisture, water-soluble vitamins, and bioactive compounds of ten selected vegetables: broccoli, brussels sprout, cabbage, eggplant, green bean, onion, red cabbage, red onion, squash, and tomato. The total color difference (ΔE) values were decreased after stir-frying the samples, except for eggplant, green bean, and tomato. The true retention of water-soluble vitamins (B1, B2, B3, and C) was increased in most vegetables after superheated-steaming, as compared to steaming and stir-frying. Moreover, compared to the uncooked vegetables, a higher true retention of total polyphenol and flavonoid was obtained for most vegetables subsequent to superheated-steaming. Total anthocyanin content was detected only in eggplant, red cabbage, and red onion, and a smaller loss of anthocyanin was determined after subjecting red cabbage to superheated-steaming. Also, the free radical scavenging activities were higher in superheatedsteaming vegetables, except in eggplant and squash. These results indicate that superheated-steaming induces a positive effect for retaining water-soluble vitamins and functional components of vegetables.