Effects of cooking methods on sensory qualities and carotenoid retention in selected vegetables

The effects of induction boiling, conventional boiling and microwave steaming on the sensory qualities and carotenoid retention of broccoli, carrots, green beans and sweet potatoes were investigated. Significantly higher cooking yields were obtained for vegetables that were induction and conventionally boiled. No differences in the retentions of alpha-carotene (a-carotene), beta-carotene (β-carotene) and lutein/zeaxanthin were observed for vegetables by the cooking method, with the exception of β-carotene retention in broccoli and sweet potatoes where retentions were higher for those that were induction boiled (90.3 and 86.1%, respectively) than those that were microwave steamed (62.2 and 66.4%, respectively). A trained panel judged the color scores of three vegetables by the cooking method as similar. The mean flavor scores (1 = extremely bland; 9 = extremely intense) for three vegetables that were conventional (4.7-5.4) and induction (5.3-5.5) boiled were lower than those that were microwave steamed (5.9-7.0). The mean texture scores (1 = extremely mushy/tender; 9 = extremely firm/tough) for all induction-boiled (5.0-6.0) vegetables were higher than those that were conventionally boiled (3.4-5.2) and lower than those that were microwave steamed (5.1-6.6).