【作者】 郭亮；

【导师】 乔旭光；

【作者基本信息】 山东农业大学 ， 农产品加工及贮藏工程， 2011， 硕士

【摘要】 大蒜（Allium Sativum L.）为百合科葱属植物。大蒜素是大蒜中主要的功能物质,化学名称为二烯丙基硫代亚磺酸酯,是大蒜破碎后蒜氨酸在蒜氨酸酶的催化作用下产生的。大蒜素在抗凝血、降血脂、解毒、抗癌、抗氧化、抗衰老以及在细胞介导免疫、体液免疫调节过程中起着十分重要的作用。大蒜素易分解,不同的提取方法得到的组分不同。本研究以邳州白蒜为原料,研究了超临界CO₂萃取压力、萃取温度、萃取时间、CO₂流量以及大蒜破碎粒径和酶解条件对大蒜素萃取效果的影响。然后对超临界萃取物进行分子蒸馏,研究了绝对压力、蒸馏温度、进料速度和蒸馏级数对大蒜素纯化效果的影响,确定了多级分子蒸馏纯化大蒜素的工艺条件。主要实验结果如下:1超临界CO₂萃取大蒜素最佳工艺的确定研究了萃取压力、萃取时间、萃取温度、CO₂流速和大蒜破碎粒径对大蒜素萃取工艺的影响,通过二次通用旋转组合设计建立数学模型,确定最佳条件为萃取压力33.7 MPa,萃取温度41.2℃,萃取时间3.4h,CO₂流速120L·h-1,破碎粒径4mm。通过L9（34）正交试验设计进行试验,确定了萃取前蒜氨酸酶解温度、酶解时间和Mn2+添加量的最佳条件为酶解温度35℃,酶解时间30min,Mn2+添加量为0.001mmol·g-1,最终萃取率为0.418%。2分子蒸馏纯化大蒜素的研究研究了绝对压力、蒸馏温度、进料速度以及蒸馏级数对超临界萃取物中大蒜素纯度和得率的影响。在单因素试验的基础上,采用L9（34）正交表确定了各级分子蒸馏最佳工艺条件,试验结果表明:一级分子蒸馏最佳条件为绝对压力200Pa,蒸馏温度50℃,进料速度15 mL·min-1;二级蒸馏最佳条件为绝对压力150Pa,蒸馏温度45℃;三级蒸馏最佳条件为绝对压力100Pa,蒸馏温度40℃;经过三级分子蒸馏,蒜素纯度达到87.19%,得率为47.45%,采用高效液相色谱法测定,大蒜素、DADs和DATs相对总含量达到83.14%。3大蒜素及相关成分的热稳定性研究在-20℃、4℃以及25℃条件下观察大蒜素、DADs和DATs的稳定性,大蒜素、DADs以及DATs稳定性随着温度的上升而明显下降,热稳定性顺序为DADs>DATs>大蒜素。更多还原

【Abstract】 Garlic（Allium Sativum L.） is the perennial herb of lily family. Allicin, whose chemical name is Allyl, 2-Porpenethiosulfinate, is a main functional substances of garlic. It comes from alliin by action of alliinase when the fresh garlic is crashing. Allicin plays an important role in anti-coagulation, lipid-lowering, detoxification, anti-tumor, anti-oxidation, anti-aging as well as in the regulation of cell-mediated immunity and humoral immunity. Allicin is easy to degenerate and different components can be obtained under different conditions of extraction. Using Pizhou garlic as the raw material, this paper studied the effects of pressure, temperature, time, flow of CO₂, particle size and the enzyme conditions on the extraction of allicin. Allicin from supercritical CO₂ extraction was purified by Molecular Distillation. And the effects of temperature, pressure, feed rate, and frequency on the molecular distillation were studied and the technologic condition of multi-molecular distillation was established. The main results were as follows:1 The optimum process conditions of supercritical CO₂ extraction.The effects of pressure, temperature, time , flow of CO₂ and particle size on the extraction of allicin were studied. And the mathematical model were obtained by the quadratic general rotary unitized design.The optimum conditions of pressure, temperature, time, flow of CO₂, particle size were 33.7 MPa, 41.2℃, 3.4 h, 120 L·h-1 and 4 mm respectively. The enzyme conditions of allin were optimized by orthogonal tests that include 4 factors and 3 levels. The optimum conditions of temperature, time and dosage of Mn2+ were 35℃, 30 min and 0.001mmol·g-1 respectively,and the final extracting rate was 0.418%.2 Studies on purification of allicin by molecular distillationThe effects of temperature, pressure, feed rate, and frequency on the purification of allicin by molecular distillation were studied. On the basis of single factor experiments, the technological parameters were optimized by orthogonal tests that include 4 factors and 3 levels. The results reveal that the optimum condition of absolute pressure, distillation temperature and feed flow rate in first-stage distillate were 50℃, 200 Pa, 15 mL·min-1 respectively; the technological condition of second- stage distillate were 45℃and 150Pa respectively and the technological condition of third-stage distillation was absolute pressure 100Pa and distillation temperature 40℃respectively.The purity and yield of allicin were 87.19% and 47.45% respectively, obtained after 3 stages of molecular distillation. The relative contents of Allicin, DADs and DATs was 83.14%,determined by HPLC.3 The thermal stability of Allicin, DADs and DATsThe thermal stability of Allicin, DADs and DATs were observed at -20℃, 4℃and 25℃respectively. After 150 days, the stability of them sharply decreased as the temperature rised, the order of stability was DADs>DATs>allicin.更多还原