The effects of different concentrations of ubiquinol-10 (Q 10H2) on citral's stability were systematically investigated and compared in citral-loaded oil-in-water (O/W) nanoemulsions. Solid phase microextraction gas chromatography (SPME-GC) was employed to monitor the degradation of citral and the formation of off-flavor compounds throughout storage at 25 and 45 C. The optimum concentration of Q10H2 in the current formulation was determined to be around 0.10 wt % in the system (Q10H2/citral ratio 1:1), which can effectively protect citral from chemical degradation and oxidation. Results suggested, however, that a low concentration of Q10H2 may induce the majority of the ubisemiquinone (Q10•-)/ubiquinone (Q 10) redox transition, which possibly endowed Q10H 2 with pro-oxidant properties. Further increase in Q 10H2 concentration beyond a certain value also hindered its effect due to the complex properties of radicals involved and the overall environment encountered. With appropriate concentrations of Q10H 2 presented in the system, major citral oxidation off-flavor compounds (p-cresol, α,p-dimethylstyrene, p-methylacetophenone), and some of the lipid degradation products can be inhibited to lower levels. In contrast, ubiquinone-10 (Q10) had a negligible effect on citral's chemical stability and off-flavor generation.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)
- citral degradation
- coenzyme Q
- lipid oxidation
- oil-in-water nanoemulsion