Abstract—Garlic (Allium sativum) is a plant well known for its extensive use in traditional and modern medicine. Its healing properties are attributed to thiosulfinates, compounds which are formed through an enzymatic reaction when garlic cloves are crushed. This research studies the suitability of these compounds known as diallyl thiosulfinate or allicin to be used as a possible bio-inhibitor for urea fertilizers when subjected to local Malaysian soil conditions especially paddy fields. A spectrophotometric assay is used to quantify allicin by using L-cysteine with the theoretically proven basis that one molecule of allicin reacts rapidly with two molecules of cysteine to form two molecules of S-allyl mercaptocysteine. 5,5’-dithiobis-(2-nitrobenzoic acid) (DTNB) is added to the mixture to form 2-nitro-5-thiobenzoate (NTB) after residual cysteine reacts with DTNB. Quantification of allicin is done at 30 °C with stock garlic extract concentration of 1 g/30 mL. This is followed by tests on allicin stability at pH 4.0 – 8.0 at 30 °C and thermal stability of allicin from 30 °C to 85 °C. The results show stability of allicin for local soil temperatures (30-35 °C) but unsuited for paddy field usage as it decomposes at pH lower than 6.0.

Index Terms—thiosulfinates, allicin, bio-inhibitor, urea fertilizer, allium sativum

Cite: Nurlidia Mansor, Ho Jian Herng, Sity Juaeiriah Samsudin, Suriati Sufian, and Yoshimitsu Uemura, "Quantification and Characterization of Allicin in Garlic Extract," Journal of Medical and Bioengineering, Vol. 5, No. 1, pp. 24-27, February 2016. Doi: 10.12720/jomb.5.1.24-27