Effects of Different Solvents Extractions on Total Polyphenol Content, HPLC Analysis, Antioxidant Capacity, and Antimicrobial Properties of Peppers (Red, Yellow, and Green (Capsicum annum L.)).

Hiba-Allah Nafidi,Khizar Hayat,Shaista Arzoo,Mohammed Musaad Althbiti,Massimo Lucarini,Nawal Albader,Abdulhakeem Alzahrani,Mohammed Bourhia,Fohad Mabood Husain,Bandar Ali M Al-Zaied,Ahmad Mohammad Salamatullah,Heba Kahlil Alyahya,Mohammed Asif Ahmed

doi:10.1155/2022/7372101

Abstract

Plants possessing various bioactive compounds and antioxidant components have gained enormous attention because of their efficacy in enhancing human health and nutrition. Peppers (Capsicum annuum L.), because of their color, flavor, and nutritional value, are considered as one of the most popular vegetables around the world. In the present investigation, the effect of different solvents extractions (methanol, ethanol, and water) and oven drying on the antioxidant and antimicrobial properties was studied of red, yellow, and green peppers. The green pepper water extract showed the highest total polyphenol content (30.15 mg GAE/g DW) followed by red pepper water extract (28.73 mg GAE/g DW) and yellow pepper water extract (27.68 mg GAE/g DW), respectively. The methanol extracts of all the pepper samples showed higher TPC as compared to the ethanol extract. A similar trend was observed with the total flavonoid content (TFC). The antioxidant assays (DPPH scavenging and reducing power) echoed the findings of TPC and TFC. In both antioxidant assays, the highest antioxidant activity was shown by the water extract of green pepper, which was followed by the water extract of red pepper and yellow pepper. Furthermore, all extracts were assessed for their potential antimicrobial activity against bacterial and fungal pathogens. Aqueous extracts of all three pepper samples exhibited slightly higher inhibition zones as compared to their corresponding ethanolic and methanolic extract. Minimum inhibitory concentration (MIC) values ranged from 0.5 to 8.0 mg/ml. The lowest MIC values ranging from 0.5 to 2.0 mg/ml concentration were recorded for aqueous extracts of green pepper. High-performance liquid chromatography (HPLC) analysis revealed tannic acid as the major phenolic compound in all three pepper samples. Thus, it is envisaged that the microwave drying/heating technique can improve the antioxidant and antimicrobial activity of the pepper.

Highlights

Antioxidants protect biological processes by delaying, controlling, or inhibiting the oxidative stress caused by free radicals [1]
A study on the efficiency of different extraction solvents using high-performance liquid chromatography (HPLC) on the bioactivity of nonpungent peppers demonstrated that solvent chemical properties such as polarity can differentially influence the efficacy of recovering bioactive compounds from foods, and this might eventually result in differences in estimated biological activity, such as antioxidant capacity [30]
Total Polyphenol Content (TPC). e effect of different extraction solvents on the total polyphenol content of green, yellow, and red peppers are shown in Figure 1. e green pepper water extract showed the highest total polyphenol content (30.15 mg GAE/g DW) followed by red pepper water extract (28.73 mg GAE/g DW) and yellow pepper water extract (27.68 mg GAE/g DW), respectively. e methanol extracts of all the pepper samples showed higher TPC as compared to the ethanol extract

Summary

Introduction

Antioxidants protect biological processes by delaying, controlling, or inhibiting the oxidative stress caused by free radicals [1]. A study on the efficiency of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and methanol-water mixture) using high-performance liquid chromatography (HPLC) on the bioactivity of nonpungent peppers demonstrated that solvent chemical properties such as polarity can differentially influence the efficacy of recovering bioactive compounds from foods, and this might eventually result in differences in estimated biological activity, such as antioxidant capacity [30]. In comparison with green and yellow sweet peppers, the orange and red sweet peppers extracted with hexane showed the highest TPCs and antioxidant activities, likely caused by carotenoids as the compounds were mainly extracted by nonpolar solvents [31]. Is study was undertaken to investigate the effect of different solvents extractions (methanol, ethanol, and water) on the antioxidant and antimicrobial properties of ovendried red, yellow, and green peppers

Materials and Methods

Results and Discussion

Reducing Power