Boiling enriches the linear polysulfides and the hydrogen sulfide-releasing activity of garlic

Garlic is rich in polysulfides, and some of them can be H2S donors. This study was conducted to explore the effect of cooking on garlic's organopolysulfides and H2S-releasing activity. Garlic bulbs were crushed and boiled for a period ranging from 3 to 30 min and the solvent extracts were analyzed by GC–MS/FID and HPLC. A cell-based assay was used to measure the H2S-releasing activity of the extracts. Results showed that the amounts of allyl polysulfides increased in crushed garlic boiled for 6–10 min; however, prolonging the thermal treatment to 20 or 30 min decreased their concentrations. Data of the H2S-releasing activity, expressed as diallyl trisulfide equivalents (DATS-E), parallel this trend, being significantly higher at 6 and 10 min boiling. Our results showed enhancement of H2S-releasing activity upon moderate boiling, suggesting that shorter cooking time may maximize its health benefits as a dietary source of natural H2S donors.