Variation in phenolic acids and antibacterial attributes of peel extracts from ripe and unripe [Citrus limon (L.) Osbeck] fruit

• Published in: Journal of food measurement & characterization Vol. 14; no. 3; pp. 1325 - 1332
• Main Authors: Mehmood, Tahir, Afzal, Anum, Anwar, Farooq, Memon, Najma, Memon, Ayaz A., Qadir, Rahman
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2020; Springer Nature B.V
• Subjects: Acetic acid; Acids; anti-infective agents; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; antimicrobial properties; Bacillus subtilis; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chloroform; Citrus fruits; Citrus limon; Diffusion rate; E coli; Engineering; Escherichia coli; Ethyl acetate; Food Science; fruit maturity; Fruits; High-performance liquid chromatography; lemon peels; Lemons; Liquid chromatography; methanol; Original Paper; p-coumaric acid; Phenolic acids; Phenols; Plant extracts; reversed-phase high performance liquid chromatography; Salmonella; Salmonella Typhimurium; Solvents; Staphylococcus aureus; Vanillin; Solvent extracts; Total phenolic contents; Antibacterial agents; peels; HPLC; Phenolic acids
• ISSN: 2193-4126; 2193-4134
• DOI: 10.1007/s11694-020-00380-w

This study reveals variation in phenolic acids and antimicrobial attributes of peel extracts from ripe and unripe lisbon lemon [ Citrus limon (L.) Osbeck] fruit. Total phenolic contents in ripened lemon peels were significantly ( p  < 0.05) higher (138.66–344.33 GAE mg/g DW) than the unripen lemon peel (122.33–277.10 GAE mg/g DW). The total amount of individual phenolic acids as analyzed by RP-HPLC in unripe and ripened peels ranged from 3.8 ± 2.2 to 1453.6 ± 66.4 and 3.4 ± 1.8 to 1772 ± 64 mg/kg, respectively with gallic, caffeic, cinnamic, syringic, vanilic, vanillin, p -coumaric, m -coumaric and o -coumaric acids as the main compounds detected. As per disk diffusion measurement, different solvent (methanol, ethyl acetate and chloroform) extracts from ripened and unripe lemon peel exhibited considerable antimicrobial activity against four bacterial strains including Salmonella typhimurium, Bacillus subtilus, Escherichia coli and Staphylococcus aureus with 50% chloroform extracts having the best potential. The composition of phenolics and antimicrobial activity of tested peels varied notably in relation to extraction solvents and fruit maturity stages. Overall, the present results support potential uses of limon peels as a natural source of high-value phenolics/antimicrobial agents for nutra-pharmaceutical developments.