Antioxidant activities from different rosemary clonal lines.

Rosemary extract is widely used in food industry and carnosic acid is reported to be the major component that is responsible for its antioxidant activities. However, it is unclear how the numerous plant metabolites interact and contribute to the overall antioxidant activity. In this study, with poultry fat as the model food system, rosemary extract from six clonal lines were evaluated that each represented a different genetic variant. As expected, rosemary extract with higher carnosic acid content had higher antioxidant activity. However, rosemary extract which had carnosic acid removed retained a significant amount of activity. Furthermore, when the individual contributions of carnosic acid and the portion without carnosic acid were evaluated separately, neither was shown to be responsible for the overall level of its stabilization effect from rosemary extract as a whole entity. The interactions among different plant metabolites have a major impact on the overall antioxidant capabilities of rosemary extract.