Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Oct 25:12:100144.
doi: 10.1016/j.fochx.2021.100144. eCollection 2021 Dec 30.

Green extraction of polyphenols from citrus peel by-products and their antifungal activity against Aspergillus flavus

Yue Liu  1 , Meryem Benohoud  2 , Joseph Hubert Galani Yamdeu  1 , Yun Yun Gong  1 , Caroline Orfila  1
Affiliations

Green extraction of polyphenols from citrus peel by-products and their antifungal activity against Aspergillus flavus

Yue Liu et al. Food Chem X. .

Abstract

Aspergillus flavus is a pathogenic fungus associated with food safety issues worldwide. This study investigated the antifungal activity of citrus peel extracts prepared using food-grade solvents (hot water or ethanol). Mandarin (Citrus reticulata) peel ethanol extracts inhibited the mycelial growth of A. flavus (39.60%) more effectively than those of orange (32.31%) and lemon (13.51%) after 7 days of incubation. The growth of A. flavus could be completely inhibited by mandarin extracts at 300-400 mg mL-1, depending on the extraction solvent. Solid-phase extraction (SPE) separated the polyphenol-rich fractions, which showed up to 40% higher antifungal activity than crude extracts. Twelve polyphenols (2 phenolic acids and 10 flavonoids) were identified by HPLC-DAD, narirutin and hesperidin were the most abundant. In conclusion, citrus peels are promising bioresources of antifungal agents with potential applications in food and other industries.

Keywords: Antifungal activity; Aspergillus flavus; CE, Crude extract; Citrus sp.; EF, Elution fraction; MIC, Minimum inhibitory concentration; PDA, Potato dextrose agar; PDB, Potato dextrose broth; PMF, Polymethoxylated flavones; Polyphenols; SPE, Solid phase extraction; Solid Phase Extraction; TFC, Total flavonoids content; TPC, Total phenolic content; WF, Washing fraction.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Fig. 1
Fig. 1
Antifungal activity (%) of ethanol extracts (10 mg/mL) from orange, lemon and mandarin citrus peels, assayed at 25 °C for 7 days. (a) Colony diameter (mm) including disc diameter of 4 mm and (b) antifungal activity (%) compared to TBQH positive control. ‘a, b, c’ represent significant differences comparing each peel extracted samples to negative control (DMSO) for colony diameter; * represents significant differences comparing orange and lemon extracts to mandarin extracts. a/***, p ≤ 0.0001; b/**, p ≤ 0.001; c/*, p ≤ 0.05 and ns, p > 0.05. Results are means of three replicated dishes.
Fig. 2
Fig. 2
Effect of concentrations (mg/mL) of water (a) and ethanol (b) extracts on A. flavus colony growth at 25 °C during 7 days.
Fig. 3
Fig. 3
Antifungal activity (%) of a) water and b) ethanol mandarin peel extracts and their SPE fractions (10 mg/mL) at 25 °C during  7 days.
Fig. 4
Fig. 4
HPLC chromatogram of mandarin peel extracts at (a) 254 nm, (b) 280 nm and (c) 330 nm. WE, water extract; EE, ethanol extracts; CE, crude extracts; WF, washing fraction; EF, elution fraction. Peaks: 2, Protocatechuic acid (internal standard); 7, ρ-coumaric acid; 8, Eriocitrin; 9, Rutin; 12, Ferulic acid; 13, Taxifolin; 14, Narirutin; 19, Hesperidin; 22, Didymin; 24, Eriodictyol; 32, Sinensetin; 33, Nobiletin; 34, Tangeretin.
Fig. 5
Fig. 5
Chemical structures of (a) p-Coumaric acid, (b) Eriocitrin, (c) Rutin, (d) Ferulic acid, (e) Taxifolin, (f) Narirutin, (g) Hesperidin, (h) Didymin, (i) Eriodictyol, (j) Sinensetin, (k) Nobiletin and (l) Tangeretin.
See this image and copyright information in PMC

References

    1. Abdel-Kareem M.M., Rasmey A.M., Zohri A.A. The action mechanism and biocontrol potentiality of novel isolates of Saccharomyces cerevisiae against the aflatoxigenic Aspergillus flavus. Letters in Applied Microbiology. 2019;68(2):104–111. doi: 10.1111/lam.13105. - DOI - PubMed
    1. Al Aboody M.S., Mickymaray S. Anti-Fungal efficacy and mechanisms of flavonoids. Antibiotics (Basel) 2020;9(2):1–42. doi: 10.3390/antibiotics9020045. - DOI - PMC - PubMed
    1. Bahorun T., Luximon-Ramma A., Crozier A., Aruoma O.I. Total phenol, flavonoid, proanthocyanidin and vitamin C levels and antioxidant activities of Mauritian vegetables. Journal of the Science of Food and Agriculture. 2004;84(12):1553–1561. doi: 10.1002/(ISSN)1097-001010.1002/jsfa.v84:1210.1002/jsfa.1820. - DOI
    1. Ben Hsouna A., Ben Halima N., Smaoui S., Hamdi N. Citrus lemon essential oil: Chemical composition, antioxidant and antimicrobial activities with its preservative effect against Listeria monocytogenes inoculated in minced beef meat. Lipids in Health and Disease. 2017;16(1):146. doi: 10.1186/s12944-017-0487-5. - DOI - PMC - PubMed
    1. Chen J.X., Yang J., Ma L.L., Li J., Shahzad N., Kim C.K. Structure-antioxidant activity relationship of methoxy, phenolic hydroxyl, and carboxylic acid groups of phenolic acids. Science Reports. 2020;10(1):1–9. doi: 10.1038/s41598-020-59451-z. - DOI - PMC - PubMed