2.7. Measurement of allicin concentration
The allicin concentration in garlic was measured using the method modified by
Miron et al. (2002). In brief, each garlic extract powder (10 mg) was dissolved in
10 mL of 50 mM Na–phosphate buffer containing 2 mM EDTA (pH 7.2). The garlic
solution (0.1 mL) was mixed with 0.9 mL of 4-mercaptopyridine (4-MP, 104 M),
which changes its absorbance spectrum upon reaction with allicin. The absorbance
was measured at 324 nm after incubation at room temperature for 30 min. A negative
control was obtained using the same procedure without garlic solution. The
concentration of allicin was calculated based on the negative control.