Antioxidant activity of thiosulfinates derived from garlic

Area of Science:

• Food chemistry
• Oxidation inhibition
• Antioxidant mechanisms

Background:

• Garlic extract exhibits antioxidant properties.
• Allicin is a key component of garlic's antioxidant activity.
• Understanding the role of allicin in oxidation inhibition is crucial.

Purpose of the Study:

• To investigate the antioxidant properties of garlic extract.
• To determine the contribution of allicin to garlic's antioxidant capacity.
• To elucidate the structure-activity relationship of thiosulfinates in antioxidant action.

Main Methods:

• Methyl linoleate oxidation assay.
• Preparation of allicin-free garlic extract using preparative HPLC.
• Electron Spin Resonance (ESR) detection to study allicin's reactivity with peroxyl radicals.

Main Results:

• Garlic extract significantly inhibited methyl linoleate oxidation.
• Allicin-free garlic extract showed substantially reduced antioxidant activity.
• Allicin scavenged peroxyl radicals, confirming its antioxidant role.
• The allyl and -S(O)S- groups in thiosulfinates are essential for antioxidant activity.

Conclusions:

• Allicin is the primary contributor to the antioxidant properties of garlic extract.
• Allicin acts as an antioxidant by scavenging peroxyl radicals.
• Specific structural features of thiosulfinates are critical for their antioxidant efficacy.