licin

Licin, commonly known as allicin, is a sulfur-containing organosulfur compound produced in garlic and related Allium species when tissue is damaged. It forms enzymatically from the sulfur-containing amino acid derivative alliin by the action of the enzyme alliinase. Allicin quickly rearranges and decomposes into other sulfur-containing compounds such as diallyl disulfide, diallyl sulfide, ajoene, and various vinyldithio compounds, which together give garlic its characteristic pungent odor and flavor.

Biological activity and health effects: In vitro studies show antimicrobial, antifungal, and antiviral properties, and some animal and human studies have explored possible cardiovascular or anticancer benefits. However, clinical evidence is mixed or inconclusive, and results vary with dosage, preparation, and metabolism. Allicin is not approved as a medicine, and its health claims are not universally accepted.

Stability and processing: Allicin is unstable at room temperature and degrades with heat and time. Freshly crushed garlic releases allicin, while drying, heating, or prolonged storage reduces its formation. The compound’s reactivity with thiols means it readily participates in chemical reactions in foods and biological systems.

Occurrence and extraction: Licin is primarily associated with garlic (Allium sativum) and to a lesser extent with other Allium species. Commercial products often use extracts or stabilized forms intended to preserve some of allicin’s flavor or activity, though stability remains a challenge.

Safety and regulation: Allicin-containing preparations are generally regarded as safe for flavoring. High-dose supplements can cause gastrointestinal upset, irritation, or allergic reactions in sensitive individuals, and may interact with anticoagulant or antiplatelet medications.