The effect of oxidizing lipid substrate on the antioxidant activity of carnosol and carnosic acid were evaluated in bulk and emulsified systems. In bulk methyl linoleate, carnosic acid was a better antioxidant than carnosol on the basis of conjugated diene hydroperoxide formation, and both were more active than α-tocopherol. However, in linoleic acid carnosol was more active than carnosic acid. In bulk corn oil triglycerides, α-tocopherol exhibited the most antioxidant activity followed by carnosic acid and carnosol. In all emulsified systems, α-tocopherol consistently exhibited more antioxidant activity than carnosol and carnosic acid. In mixtures, carnosol decreased and carnosic acid increased the oxidative stability of α-tocopherol in corn oil. During oxidation carnosic acid and carnosol are converted to unknown compounds which exhibit antioxidant activity. The type and polarity of the lipid system used as a model substrate significantly affect the antioxidant activity of carnosol and carnosic acid.
- Carnosic acid
- Corn oil
- Linoleic acid
- Methyl linoleate
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Food Science
- Chemistry (miscellaneous)
Effect of Different Lipid Systems on Antioxidant Activity of Rosemary Constituents Carnosol and Carnosic Acid with and without α-Tocopherol. / Hopia, Anu I.; Huang, Shu Wen; Schwarz, Karin; German, J. Bruce; Frankel, Edwin N.In: Journal of Agricultural and Food Chemistry, Vol. 44, No. 8, 08.1996, p. 2030-2036.
Research output: Contribution to journal › Article