Background: Economically important vegetables are a strong source of antioxidants with different characteristics. Capsicum L. (pepper) is an important agricultural plant because of its economical, medicinal, and nutritional values.
Methods: This study aimed to test antioxidant parameters in the fruits of 9 cultivars of Capsicum annuum L. (CA 01-09), 7 cultivars of C. baccatum L. (CB 01-07), and 11 cultivars of C. chinense Jacq. (CC 01-11). The antioxidant activity of the investigated Capsicum cultivars was measured, along with the free radical scavenging activity (FRSA), using the DPPH method, and the molybdenum reducing power (MRP) was expressed as mg TE (Trolox equivalent) per g of DW (dry weight). Total polyphenol content (TPC), expressed as mg GAE (gallic acid equivalent) per g of DW, total flavonoid content (TFC), expressed as mg QE (quercetin equivalent) per g of DW, and total phenolic acid content (TPAC), expressed as mg CAE (caffeic acid equivalent) per g of DW, were the basic antioxidant parameters of antioxidant activity in this study.
Results: All investigated Capsicum extracts exhibited FRSA from 1.45 (CC-06) to 8.21 (CC-05) mg TE/g and MRP from 24.84 (CA-06) to 198.21 (CB-07) mg TE/g. The TPC of the tested extracts ranged from 10.13 (CB-03) to 38.68 (CB-07) mg GAE/g. The TFC of the studied samples showed values from 5.73 (CB-03) to 27.32 (CB-07) mg QE/g and TPAC from 2.24 (CB-03) to 13.07 (CC-07) mg CAE/g. A very strong correlation was found in the investigated cultivars between TPC and TPAC (r = 0.932, 0.839 and 0.848, respectively), and between TPC and TFC (r = 0.921, 0.982 and 0.939, respectively). Very strong relations were also found between TPC and FRSA (r = 0.820) in the C. annuum cultivars and between TPC and MRP (r = 0.898) in the C. baccatum cultivars.
Conclusions: This study found useful results concerning the antioxidant potential of the fruits of Capsicum cultivars. The data obtained demonstrate the strong antioxidant activity of cultivars of Capsicum, which can be used in the food industry because of the commercial importance of these fruits.
Keywords: Capsicum spp.; antioxidant activity; cultivars; phenolic compounds.