Studies On Determination And Membrane Purification Of Allicin

Garlic (Allium sativum L.) is a widely consumed herb in foodstuffs and medicines. Allicin (diallylthiosulfinate) is the main biologically active component of freshly crushed garlic cloves. It is produced upon the interaction of the nonprotein amino acid alliin with the enzyme alliinase (alliin lyase, EC 4.4.1.4). Epidemiological, clinical and laboratory studies have shown that allicin possesses a vast variety of diverse biological activities, including antimicrobial, anti-inflammatory, antivirus, antioxidant, antiatherosclerotic, anticancer, antihypertensive, immuno-stimulatory. Allicin is chemically an unstable and highly reactive molecule.The methods of extracting Allicin can be classified three: extracted by hydrodistillation, extracted by organic solvent(SE) and extracted by supercritical fluid extraction(SFE) .There is little impurity in garlic oil extracted by hydrodistillation but little Allicin , either , otherwise , there is a lot of needless substance in garlic oil extracted by SFE and with a boring subsequent purification .Membrane technology has many excellences as the following: low energy consumption, safety, no addition of chemicals, retention of nutrients, elimination of wastewater treatment, simple operation. The last decade has shown a rapid growth and improvement of membrane technology in a great number of applications.The methods for estimation of allicin are mainly: GC, HPLC, TLC, Lawson spectrophotometric assay, fix sulfur method and mecury nitrate method. The chromatography methods all require sophisticated instruments and allicin standard sample, which make the determination of allicin complicated and expensive. Fix sulfur method and mecury nitrate method are the determination methods of total sulphur-containing flavour compounds. They neither can be used as the quantitation method of allicin.In this paper Lawson spectrophotometric assay was improved for better accuracy. Then the garlic extract liquid was purified by membrane separation process. Single factor analysis was used to analyze the influences of pressure, temperature and pH to membrane flux. And membrane pollution and cleaning were studied. Last, sulphur-containing flavour compounds in the product were analyzed by GC-MS.