Evaluation of in vitro Antioxidant Potential of Capsicum (Capsicum annuum) of Different Ripening Stages Extracted at Different Temperature and pH

Capsicum (Capsicum annuum) of different ripening stages contains different biochemicals that might be altered by the cooking processes practiced in the different part of this country. The present study was designed to analyze their in vitro antioxidant profile before and after thermal processing in water at different temperatures and pH. Thermal processing was done at 60oC, 80oC and 100oC, whereas pH 5.0 and 9.0 were also used for extraction. The assays performed included DPPH radical decolorization assay, reducing power assay and assay for total phenolic contents. It was observed that the reducing power and total phenolic content improved in case of all the three different maturity stages of the vegetable after thermal processing and pH dependent extraction. DPPH radical scavenging ability, however, was diminished. This indicated that non-polar antioxidants were not extracted in the extraction conditions. Improved antioxidant profile in aqueous assay systems was probably due to better solublization of the polar antioxidants in hot water and different acid-base conditions. Improvement in the total phenolic contents substantiated the radical scavenging abilities of the three variants after aqueous extraction.