HPLC analysis of thiosulphinates in aqueous extracts from garlic (Allium sativum L.)

The qualitative and quantitative content of thiosulphinates in aqueous extracts of garlic powder, as well as from fresh garlic bulb (Allium sativum L.) was analysed. The stability of thiosulphinates in freshly prepared aqueous extract from garlic, aqueous extracts prepared from garlic powder stored 4 days at room temperature (293 K) as well as extract prepared from powder stored for 18 months at 278 K was also analyzed by use HPLC. Allicin (allyl thiosulphinate), allyl-methyl-/methyl-allyl-thiosulfinate and methyl-thiosulfinate are the most representative components in freshly prepared aqueous extracts from garlic bulbs and from garlic powder. The stability of these sulphinates is very low at room temperature. The highest stability was detected in the case of extract prepared from powder sample stored for 18 months at 273K. The content of allicin and other thiosulphinates in such extract is almost equal to the content of thiosulphinates in fresh garlic bulb.