Evaluation of antioxidant and antimicrobial activities of mandarin peel (Citrus reticulata blanco) with microwave assisted extract using two different solvents

Abstract

Background and Objective: Mandarin peel is the biggest source of bioactive phenolic compounds, specifically flavonoids, with comparatively higher polyphenol content compared with the edible parts. The flavonoids content in citrus consist of flavones, isoflavones, flavonones, flavonols and anthocyanins. The objective of this study was to determine the antioxidant content as an antibacterial activity of peel mandarin using microwave method and two different solvents (distilled water and ethanol) for extract. Materials and Methods: The plant was collected in Kahramanmaras, Turkey. The study performed the extraction methods using water and ethanol with the assist of microwave. The extracts were assessed for yield extraction, total condensed tannins, total phenolic compounds, flavonoid contents, anthocyanin and antimicrobial activity against some antibiotics. Results: The yield extraction for water extract was 38.40% which was significantly (p<0.01) different than ethanol. The total tannin of ethanol extract content was 0.083% and seems to significantly (p<0.01) higher than water. Similarly, the total phenolic and flavonoid contents were 1.862 mg GAE/g and 0.1975 mg CE/g, respectively in ethanol and water extraction. Whereas, anthocyanin content was 26.710 mg kg-1 in water extraction method and was higher significantly. Antimicrobial results showed that the peel mandarin extract has not significant effect to all bacteria. The significant results of MIC were obtained for Bacillus subtilis at the concentration 125 µg mL-1 and Klebsiella pneumonia at the concentration of 250 µg mL-1. Conclusion: This study showed that mandarin peel can be considered a good natural antioxidant source to human health.