The Extraction, Separation And Purification Of Alliin

Garlic(Allium sativum L.), is a perennial herb plant of the Liliaceae Allium. As a naturally medicinal and edible plant, garlic is antibacterial, anti-inflammatory and it plays a special role in preventing and curing cardiovascular disease and cancer. Alliin, as a precursor of allicin which is the effective functional ingredient of garlic, is a valid indicator of the garlic quality. Therefore, the research on selecting the varieties of high alliin content and extracting high purity of alliin for medical use is of great commercial value. Based on the fact that alliin can be easily decomposed by allinase and produce highly unstable substance allicin, this experiment studied the enzyme inactivation conditions, the extraction conditions, and the purification processes.1. The experiment compared three different enzyme inactivation or inhibition methods, including the high temperature treatment, microwave treatment, and methanol treatment to find the effects on enzyme alliin and its content. The results showed that:the alliin content was 87.5%,61.3%,46.9% by the treatment of microwave, boiled and methanol respectively.2. In this experiment, we compared the alliin content of different garlic areas and defined the optimum extraction processes of alliin by the method of orthogonal exper iment. The optimal extraction processes were:the time of ultrasonic extraction was 30 min and the ratio of solid-liquid was 1:2.3. The experiment studed the purification processes of the fresh garlic extraction and determined the optimum condition of purification. we real-time monitored the effluent liquid by using the TLC method and purificated the effluent liquid by the method of cation exchange resin and high-efficient countercurrent chromatography respectively. Compared the results of different purification methods, we defined the high-efficient countercurrent chromatography separation conditions:it used petroleum ether-ethyl acetate-methanol-0.5% acetic acid water solution (2:5:2:5) as the two phase solvent systems. The upper phase was chosen as the stationary phase and the lower phase was chosen as the mobile phase. The mobile phase was operated at a flow rate of 0.6mL/min, while the apparatus rotateed at 850r/min and the temperature was set at 25?. Alliin which was gained through high-efficient countercurrent chromatography separation was purer than that gained through the method of cation exchange resin. The collected fractions was crystallized, and the purity of crystals was measured up to 90.75% through the liquid detection. The fractions was measured by cation exchange resin separation crystallization process, the purity of the crystallization can reach 79.61% through liquid phase detection.4. Based on the structure of alliin, we studyed the alliin stability through the influence of temperature, organic solvent, water, and oxidant. The results were that:the organic solvent, water and temperature had little effect on alliin, while the alliin was unstable by the effect of oxidant.