Antimicrobial effect of methyl-β-cyclodextrin- curcumin complex as a potential food preservative

E. Mwangi, I. Shlar, B. Horev, Y. Vinokur, V. Rodov
Natural food preservatives are of great interest for the industry due to their potential to control microbial food spoilage and foodborne diseases without hazardous chemical residues. Use of plant-derived phenolic compounds may be a promising nature-inspired antimicrobial approach. Curcumin, an edible GRAS (generally recognized as safe) natural phenylpropanoid derivative, has gained attention as a potential “green” antimicrobial agent. The present study evaluated antimicrobial efficacy of curcumin against Gram-negative and Gram-positive bacteria, and tested its potential as food preservative on fresh unpasteurized carrot juice under temperature-controlled conditions. Due to the limited water solubility of curcumin, it was applied in a form of methyl-β-cyclodextrin (MBCD) inclusion complex. Escherichia coli ATCC 25922 and Bacillus subtilis NCIB 3610 served as examples of Gram-negative and Gram-positive bacteria, respectively. Minimum inhibitory concentration (MIC) values of curcumin toward Gram-negative and Gram-positive bacteria were both 0.4 mM (147 μg mL ‑1). At the same time, at sub-MIC doses Gram-positive bacterium (B. subtilis) was more sensitive to curcumin than the Gram-negative one (E. coli). Adding 0.4 mM curcumin to freshly prepared carrot juice prevented the microbial proliferation at 20°C and caused a 1-log population decline in the juice kept at 4°C. Furthermore, the effect of curcumin against yeast and molds was also evident. The study has shown that curcumin in the form of MBCD inclusion complex is active against wide range of microorganisms and demonstrates promising efficacy as a potential “green” food preservative.
Mwangi, E., Shlar, I., Horev, B., Vinokur, Y. and Rodov, V. (2021). Antimicrobial effect of methyl-β-cyclodextrin- curcumin complex as a potential food preservative. Acta Hortic. 1319, 81-88
DOI: 10.17660/ActaHortic.2021.1319.10
phenylpropanoids, minimum inhibitory concentration, Escherichia coli, Bacillus subtilis, carrot juice, total aerobic count, mold and yeast count

Acta Horticulturae