Impact of household cooking techniques on colour, antioxidant and sensory properties of African pumpkin and pumpkin leaves.

The objective of this investigation was to evaluate household cooking techniques on the changes of colour properties, antioxidants and antioxidant activity (FRAP activity), as well as the sensory quality of African pumpkin and pumpkin leaves. Steaming reduced the colour difference (ΔE) in the leaves of African pumpkin and pumpkin compared to stir-frying, boiling or microwaving. Steaming led to a reduced loss of total chlorophyll content but increased the total carotenoid content by 22.65% in leaves of African pumpkin compared to the other three methods. Steaming reduced the loss of total phenolic content and retained the antioxidant activity in both African pumpkin and pumpkin leaves compared to the other methods, whilst stir-frying and steaming reduced the loss of total flavonoids in the leaves of African pumpkin and pumpkin, respectively. The sensory evaluation indicated that the stir-fried leaves of African pumpkin and pumpkins are preferred, whilst the steamed leaves are preferred secondly, compared to the boiled or microwaved leaves, which are least tasty. • Steaming reduced the loss of total chlorophyll content in African pumpkin leaves. • Steaming increased the total carotenoids in African pumpkin leaves than raw leaves. • Steaming reduced the loss of antioxidant activity in the leaves of African pumpkin and pumpkin. • Boiling and microwaving caused greater loss of the antioxidants and the antioxidant activity. • Steaming is the suitable cooking technique for African pumpkin and pumpkin leaves. [ABSTRACT FROM AUTHOR]