Anti-oxidant content of different coloured sweet peppers, white, green, yellow, orange and red ( Capsicum annuum L.).

Five different coloured sweet peppers ( Capsicum annuum cv. Signal), white, green, yellow, orange and red were analysed for total carotenoids, α-tocopherol, sugars (glucose, fructose and sucrose), organic acids (citric and ascorbic acids) and anti-oxidant properties. The mature fruits, ‘Signal Red’, ‘Signal Orange’ and ‘Signal Yellow’ contained higher carotenoids, α-tocopherol, sugars and organic acids than the immature fruits, ‘Signal Green’ and ‘Signal White’. Among the mature fruits, ‘Signal Red’ was the highest in total carotenoids [9.15 mg (100 g)−1 of fresh weight] while ‘Signal Orange’ was the highest in α-tocopherol [5.40 mg (100 g)−1 of fresh weight]. ‘Signal Red’ and ‘Signal Orange’ contained the most sugars and organic acids. The suppression of 2,2′-azobis (2,4-dimethylvaleronitrile) (AMVN)-induced oxidation of methyl linoleate by the acetone extracts from the coloured sweet peppers resulted as follows: ‘Signal Red’ > ‘Signal Orange’ ≈ ‘Signal Yellow’ > ‘Signal Green’ ≈ ‘Signal White’. The order of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the acetone extracts was similar to that of suppression of methyl linoleate oxidation. [ABSTRACT FROM AUTHOR]