In order to study the stability of allicin. an active constituent of garlic
extract, the rate of formation of allicin from allicin and that of decompo
sition of allicin to volatile oil/sulphides has been determined by chlorami
ne-T method. The effect of acetic acid (5-30%), ethanol (5-30%), buffers (p
H 4.0-6.0) and temperature (30-50 degreesC) on the rate of formation of all
icin and on the rate of its further decomposition to volatile oil has been
studied. It has been observed that the decomposition of allicin decreases w
ith an increase in the strength of acetic acid and increases with an increa
se in the pH of macerating medium. The increasing strength of ethanol in ma
cerating medium had a little effect of the rate of decomposition, which was
found to be maximum at an incubation temperature of 35 degreesC.