Evaluation of functional groups of bioactive compounds, antioxidant potential, total phenolic and total flavonoid content of red bell pepper extracts

Today, increasing attention is paid to natural antioxidants and preservatives, including plant extracts. The aim of this study was to identify the functional groups of bioactive compounds, antioxidant activity, total phenol and total flavonoids of ethanolic, aqueous and hydroalcoholic extracts of red bell pepper. Red bell pepper extracts were extracted using ethanol, water and a mixture of water and ethanol (50-50%), respectively. Factor groups were qualitatively identified and investigated by Fourier transform infrared spectroscopy (FTIR). Total phenol was calculated using Folin-Ciocalteu reagent and the number of total flavonoids was calculated by aluminum chloride colorimetry. The antioxidant activity of red bell pepper extracts was evaluated by DPPH and ABTS free radical scavenging tests and the decay of color of beta-carotene/linoleic acid. The presence of C-C and OH groups of polyphenolic compounds of red bell pepper extract was confirmed by FTIR. The phenols of ethanolic, aqueous and hydro-alcoholic extracts of red bell pepper were equal to 22.68, 19.50 and 20.80 mg GAE / g, respectively. The flavonoid content of ethanolic, aqueous and hydro-alcoholic extracts were calculated to be 39.30, 29.28 and 33.70 mg QE / g, respectively. Antioxidant capacity of red bell pepper extracts based on radical scavenging activity of DPPH, ABTS and decay of color of beta-carotene/linoleic acid, 53.39, 59.38 and 56.88 percent for ethanolic extract, 46.37, 51/28 and 48/20 percent for aqueous extract and hydro-alcoholic extract were 51, 57.66 and 49.60 percent. According to the results, it seems that ethanolic, aqueous and hydroalcoholic extracts of red bell pepper can be used as antioxidants and natural preservatives in the food industry to prevent oxidation of food products.