Characterization of Essential Oils and Ethanolic Extracts from Nine Pepper Species: Antioxidant and Antimicrobial Activity and Spectroscopic Analysis

This study examined the characteristics of essential oils and ethanolic extracts from nine pepper species' fruits to determine their chemical compositions and assess their biological activity. Ethanolic extracts and essential oils were analyzed using HPLC, GC-MS, FTIR, and ¹H NMR spectroscopy. The total phenolic content, total flavonoid content, antioxidant activity (DPPH assay), and antibacterial efficacy against five bacterial strains were assessed. Additionally, multielement analysis was performed using the TXRF method. The results demonstrated that the yields and chemical compositions differed markedly according to the pepper origin and extraction method. Ethanolic extracts consistently demonstrated greater total phenolic content and total flavonoid content and enhanced antioxidant and antibacterial properties relative to their respective essential oils. The increased bioactivity is due to the presence of non-volatile, polar compounds, which are not effectively transferred via hydrodistillation. Piperine was solely detected in extracts from black, green, white, Bengali, and Voatsiperifery peppers. This study emphasizes the necessity of optimizing extraction techniques to enhance the bioactivity of pepper extracts, highlighting their potential as sources of natural antioxidants and antibacterial agents.