Food Chem. 2017 Feb 15;217:726-34. doi: 10.1016/j.foodchem.2016.09.030. Epub 2016 Sep 7.
- 1Laboratory of Aromatic and Medicinal Plants,
Biotechnology Center of Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia;
Faculty of Life and Environmental Sciences, University of Tsukuba,
Ibaraki 305-8572, Japan.
- 2Laboratory of Aromatic and Medicinal Plants, Biotechnology Center of Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia. Electronic address: Hanenfalleh@gmail.com.
- 3Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan.
- 4Laboratory of Aromatic and Medicinal Plants, Biotechnology Center of Borj-Cédria, BP 901, 2050 Hammam-lif, Tunisia.
Abstract
The
objective of this study is to evaluate the effect of either a solution
of Thymus capitatus essential oil or its nanoemulsion on the quality of
milk contaminated by bacteria. After 24h of S. aureus inoculation,
bacterial growth reached 202×10(3)CFU/ml in the presence of the
essential oil while it was limited to 132×10(3)CFU/ml when treated with
nanoemulsion. The reduction of antioxidant capacity of milk treated with
essential oil was higher when treated with nanoemulsion. Moreover, free
essential oil was more efficient in protecting proteins from
degradation than the nanoemulsion. For instance, after 24h of E. hirae
contamination, 26% of the total proteins were consumed in the presence
of nano-encapsulated essential oil, while only 14% of the initial
content was consumed when free essential oil was added. Concerning milk
acidity increase and the inhibition of peroxide production, no
statistical differences have been recorded between the use of free
essential oil or its nano-emulsion. In conclusion, bulk or
nano-encapsulated T. capitatus essential oil preserve milk quality and
can extend its shelf life.
Copyright © 2016 Elsevier Ltd. All rights reserved.
KEYWORDS:
Essential oil; Gram(+) bacteria; Milk quality; Nanoemulsion