Investigation of Allicin Stability in Aqueous Garlic Extract by High Performance Liquid Chromatography Method

Aims: The aims of this work were to quantify allicin - an abundant antioxidant in different aqueous garlic extract samples and to determine the stability of allicin in the extract under different thermal and solvation conditions.
Study Design: Descriptive research.
Place and Duration of Study: Department of Chemistry and Biochemistry and Department of Biological Sciences, California State Polytechnic University, Pomona, between May 2013 and September 2014.
Methodology: A reversed-phase high performance liquid chromatography method was used to analyze allicin in garlic extracts. Quantification of allicin in garlic extracts was made by comparing its peak area with the standard calibration curve of allicin with known concentrations. The kinetic study of allicin degradation in garlic extracts was based on the Arrhenius theory.
Results: The amount of allicin in aqueous garlic extracts varied from 35.6 to 44.5 mM. The thermal stability study shows that the degradation of allicin is a first-order reaction and the preliminary data shows that the degradation of allicin in different solvents has different kinetic parameters.
Conclusion: The concentration of allicin in garlic extract samples was similar to each other, despite of different sampling dates. For medicinal purpose, garlic extracts should be used freshly to prevent any degradation of allicin.