**4. Conclusions**

A quantitative method for the identification of rosemary extract in edible oils, processed meat products, and dressings was developed and validated using HPLC-PDA. The analytical method

has been verified in accordance to the ICH guidelines. The validated HPLC-PDA analysis method is suitable for the determination of rosemary extract in edible oils, processed meat products and dressings. The validated method was verified through real sample analysis; none of the tested samples showed the presence of rosemary extracts. In addition, a functional evaluation of rosemary extract as an antioxidant was carried out. We confirmed that carnosic acid has superior antioxidative and oxidative stability compared to carnosol. These results demonstrate that the validated method is suitable for identification and quantification of rosemary extract and can be used to verify the safety of edible oils, processed meat products, and dressings that containing rosemary extracts residues. In addition, functional evaluation of the rosemary extract as an antioxidant has provided an effective use for rosemary extracts.

**Author Contributions:** Methodology, S.-H.C., G.-W.J., B.-Y.C., J.-S.L., D.-Y.K. and O.-H.L.; validation, S.-H.C., G.-W.J. and S.-I.C.; resources, D.-B.K. and X.H.; data curation, T.-D.J. and W.-S.S.; writing—original draft preparation, S.-H.C. and G.-W.J.; writing—review and editing, S.-H.C., G.-W.J. and O.-H.L.; supervision, O.-H.L.; project administration, O.-H.L.; funding acquisition, O.-H.L.

**Funding:** This research was funded Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, gran<sup>t</sup> number NRF-2017R1D1A3B06028469.

**Acknowledgments:** This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A3B06028469) and has been worked with the support of a research gran<sup>t</sup> of Kangwon National University in 2017.

**Conflicts of Interest:** The authors declare no conflict of interest.
