Abstract
Thyme is a good source of antioxidant compounds but it can be contaminated by microorganisms. An experimental fluid bed ultraviolet (UV) reactor was designed for microbial decontamination of thyme samples and the effect of shortwave ultraviolet light (UV-C) radiation on antioxidant properties of thyme was studied. Samples were exposed to UV-C radiation for 16 or 64 min. UV-C treatment led to 1.04 and 1.38 log CFU/g reduction of total aerobic mesophilic bacteria (TAMB) counts. Hunter aâ̂ -value was the most sensitive colour parameter during UV-C treatment. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of extracts was not significantly affected by UV-C. Addition of thyme extracts at 0.15 and 0.3 μmol GAE/ml emulsion delayed the formation of lipid hydroperoxides and headspace hexanal in the 5.0% (wt) corn oil-in-water emulsion from 4 to 9 and 14 days, respectively. No significant changes in oxidation rates were observed between UV-C treated and untreated samples at same concentrations.
| Original language | English |
|---|---|
| Pages (from-to) | 167-173 |
| Number of pages | 7 |
| Journal | Food Chemistry |
| Volume | 157 |
| DOIs | |
| Publication status | Published - 15 Aug 2014 |
Funding
This research was partly financially supported by the grant from ITU BAP Project No: 36019 ( Istanbul Technical University Scientific Research Projects Department ).
| Funders | Funder number |
|---|---|
| ITU BAP | 36019 |
| Istanbul Teknik Üniversitesi |
Keywords
- Antioxidant activity
- Corn oil-in-water emulsion
- Oxidation
- Shortwave ultraviolet
- Thyme