Antioxidant Activity of Carnosic Acid and Methyl Carnosate in Bulk Oils and Oil-in-Water Emulsions

Shu Wen Huang, Edwin N. Frankel, Karin Schwarz, Robert Aeschbach, J. Bruce German

Research output: Contribution to journalArticle

99 Scopus citations

Abstract

This study was aimed at evaluating the antioxidant activities of carnosic acid and its methyl ester, methyl carnosate, in inhibiting the formation and decomposition of hydroperoxides in bulk and emulsified corn oil triglycerides at 60 °C. In both lipid systems, methyl carnosate was a better antioxidant than carnosic acid, and both were more active than α-tocopherol. The difference in antioxidant activity between methyl carnosate and carnosic acid was greater in emulsion than in bulk systems. Carnosic acid was less stable than methyl carnosate and α-tocopherol in bulk corn oil and 1% Tween 20 micelle solution. The partitioning of carnosic acid into the water phase may explain its low activity in emulsions. The measurement of antioxidant depletion may not be a valid method to evaluate antioxidant activities because the antioxidant activities of carnosic acid and methyl carnosate were not related to their oxidative stability in bulk oil and Tween 20 solution.

Original languageEnglish (US)
Pages (from-to)2951-2956
Number of pages6
JournalJournal of Agricultural and Food Chemistry
Volume44
Issue number10
StatePublished - Oct 1996

Keywords

  • α-tocopherol
  • Antioxidants
  • Carnosic acid
  • Corn oil triglycerides
  • Emulsion
  • Hexanal
  • Hydroperoxides
  • Interfacial oxidation
  • Mechanism
  • Methyl carnosate
  • Oxidative stability of antioxidants
  • Partition coefficient

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Food Science
  • Chemistry (miscellaneous)

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  • Cite this

    Huang, S. W., Frankel, E. N., Schwarz, K., Aeschbach, R., & German, J. B. (1996). Antioxidant Activity of Carnosic Acid and Methyl Carnosate in Bulk Oils and Oil-in-Water Emulsions. Journal of Agricultural and Food Chemistry, 44(10), 2951-2956.