基于主成分分析的大蒜药用质量评价

通过比较分析大蒜的药用品质,建立大蒜药用质量评价体系。以水分、灰分、水溶性浸出物、大蒜素含量、蒜氨酸含量、大蒜辣素含量和蒜酶活力为指标,分析甘肃民乐、江苏邳州、山东金乡、河南郑州、重庆巫溪和新疆且末、拜城、种马场、虎头镇、大有镇、新地乡等11个产地大蒜的药用品质特征及差异,并通过相关性分析、主成分分析和聚类分析对大蒜质量进行综合评价。结果表明,不同产地大蒜的上述指标都具有显著性差异。相关性分析表明,蒜酶活力与水分呈极显著正相关性（P<0.01）,蒜氨酸含量与灰分和大蒜辣素含量呈显著正相关性（P<0.05）。利用主成分分析可筛选出3个累计贡献率达到81.134%的主成分,在贡献率最大的第1主成分中,蒜氨酸对大蒜药用品质影响最大,其次为大蒜辣素和蒜酶活力。对11个产地大蒜进行综合评价,甘肃民乐大蒜的主成分综合评分得分最高为1.44,其余4个得分大于零的皆为新疆大蒜。系统聚类分析可将大蒜聚为四类,其中郑州大蒜单独为一类,金乡、巫溪和种马场大蒜聚为一类,新地、大有和民乐大蒜聚为一类,其余三地聚为一类。蒜氨酸、大蒜辣素和蒜酶活力可用于体现不同产地大蒜药用品质间的差距,利用综合评分可筛...     

丙酮酸差量法测定大蒜中大蒜辣素含量方法的建立

通过测定经酶促反应后大蒜鳞茎中的丙酮酸含量,以灭酶组大蒜鳞茎中丙酮酸含量为本底,应用丙酮酸差量法计算得出大蒜鳞茎中大蒜辣素含量,并对测定条件进行优化。结果表明:大蒜本底灭酶条件为100℃水浴加热30 min,酶促反应温度为30℃,酶促反应时间为10 min,在520 nm下测定吸光度值,丙酮酸含量浓度在10~50μg/m L内与吸光度呈良好的线性关系,大蒜辣素测定精密度相对标准偏差为0.88%,重现性相对标准偏差为1.05%。该方法操作简单、稳定、重复性好,对于测定大蒜中大蒜辣素切实可行。     

阳极溶出伏安法间接测定大蒜中的大蒜辣素

报道了大蒜中大蒜辣素含量的阳极溶出伏安测定新方法。在pH5～6的50%乙醇体系中,用过量硝酸铅沉淀大蒜样品氧化产物中的SO42-,直接移取上清夜,在电化学分析仪上用阳极溶出伏安法测定过量的Pb2+浓度,从而间接测定大蒜辣素含量。结果表明:本法测得大蒜中大蒜辣素含量为0.38%,方法的相对标准偏差(RSD)为1.42%～2.39%,方法与重量法结果对照,简单快速,可用于实际样品分析。     

大蒜加工中阿霍烯产生过程的研究

阿霍烯是一种高生物活性硫化物,具有预防心血管疾病等功能。在新鲜大蒜中阿霍烯的含量极少,且稳定性差。本文用新鲜大蒜中的内源酶将其加工成富含阿霍烯的"黑大蒜"制品,调查国内外12种大蒜在加工中蒜氨酸、大蒜辣素和阿霍烯含量的变化,分析各成分含量之间的定量关系,以揭示阿霍烯的产生过程。试验结果表明,蒜氨酸含量在加工中逐渐减少,并趋于平衡;大蒜辣素含量在加工前、后都较低,而加工第2天出现最大值(即最大生成量);阿霍烯含量在加工20d内随时间呈线性增加。黑大蒜制品的阿霍烯含量随大蒜辣素含量的增加呈线性增加,大蒜辣素含量随新鲜大蒜中蒜氨酸含量的增加呈线性增加,充分说明蒜氨酸经过大蒜辣素向阿霍烯的转化过程。当新鲜大蒜中蒜氨酸含量为5.94%时,黑大蒜制品中阿霍烯的含量可达新鲜大蒜的17.5倍。     

真空冷冻干燥制备大蒜蒜粉的工艺研究

本文以新疆吉木萨尔紫皮蒜蒜粕为原料,采用真空冷冻干燥方法制备蒜粉,测定原料的电阻值、共晶点和共熔点,为确定真空冷冻干燥温度奠定了基础。并以大蒜辣素为指标,在单因素实验的基础上进行正交试验,确定最佳工艺参数为：物料厚度为10mm,预冷时间为2h,升华时间为4h,解析时间为3h,此时大蒜辣素含量最高为1．295％。     

大蒜的新鲜吃法

一、大蒜的特殊功效 大蒜辣素,是大蒜的主要功效成分,生吃大蒜,大蒜辣素才能起到杀菌作用。     

影响蒜素提取率的因素研究

大蒜中含有人体所必须的多种营养物质,其主要活性成分是大蒜辣素、蒜氨酸、大蒜新素等化合物,主要的风味成分是蒜辣素。为了避免食用调和蒜油产品中的有机溶剂残留和有效成分的损失,本研究直接采用一级菜籽油常温浸提蒜素等成分,由于大蒜中蒜辣素的含量高低及稳定性直接影响蒜油的质量。因此考察了大蒜与提取油质量比、提取时间和大蒜破碎度等因素对蒜素含量及提取工艺的影响,结果表明当蒜油质量比为1.2∶1,浸提时间12 h,大蒜打浆时间为1.5 min时,蒜辣素含量最高,达到0.2813 g/dL。     

不同地理居群大蒜药用活性成分含量差异明显

大蒜是一种重要的药食两用植物,蒜氨酸是大蒜功效成分大蒜素的前体。新鲜大蒜经过捣碎、压碎或咀嚼并放置适当时间,可使其中的蒜氨酸经蒜酶催化裂解产生大蒜辣素。新疆师范大学化学化工学院等专家以新疆及其他部     

浅谈大蒜系列产品的开发现状

大蒜古名葫,又名葫蒜、独蒜,为百合科葱属植物蒜(AlliumSativumL.)的鳞茎,是香辛类蔬菜之一。大蒜中的有效成分有大蒜辣素、大蒜新素及多种烯丙基硫醚化合物,总称为大蒜素或大蒜精油。它含有大量对人体有益的蛋白质、氨基酸、维生素、脂肪、糖类、尼克酸、核黄素、微量元素及硫化物等,尤以微量元素硒含量较高。1990年8月在美国召开的关于大蒜保健意义及其成分的首届会议证实了大蒜能在不同程度上防治结肠癌、膀胱癌、皮肤癌和肝癌。目前,大蒜制剂如大蒜注射液、大蒜素、大蒜新素等已用于医学临床中。因此大蒜系列产品开发前景将十分广阔。…     

超声辅助三相分配法同步提取大蒜中大蒜辣素和多糖的工艺优化

为了优化超声辅助三相分配法同步提取大蒜中大蒜辣素和多糖工艺。以大蒜为原料,分别考察聚乙二醇质量分数、硫酸铵质量分数、超声温度和超声时间对大蒜辣素和多糖提取量的影响,并根据Box-Behnken试验设计优化大蒜辣素和多糖同步提取工艺条件。结果表明,最佳提取工艺条件为:聚乙二醇质量分数为24%,超声温度为34 ℃,超声时间为50 min,此条件下大蒜辣素和多糖的提取量（按干燥品计算）可达3.564、43.86 mg/g。优化后的提取工艺可高效同步提取大蒜中大蒜辣素和多糖,可为天然大蒜功能性产品的深度研究、开发与应用奠定一定的基础。     

气相色谱法测定大蒜精油软胶囊中大蒜素含量的不确定度评定

目的 评定气相色谱法测定大蒜精油软胶囊中大蒜素含量的不确定度。方法 采用气相色谱法测定大蒜精油软胶囊中大蒜素的含量。根据JJF 1059.1-2012《测量不确定度的评定与表示》的有关规定, 建立数学模型, 分析影响大蒜素含量的不确定度因素, 量化各个不确定度分量, 合成不确定度。结果 气相色谱法测定大蒜精油软胶囊中大蒜素含量的不确定度主要来源于标准溶液配制、样品重复测定和溶液的稀释; 测定结果合成不确定度为0.009%, 扩展不确定度为0.018%, 大蒜素含量测定结果为(1.356±0.018)%, k=2。结论 建立的不确定度评定方法适合气相色谱方法测定大蒜精油软胶囊中大蒜素含量不确定度分析, 为评价测定方法以及检测结果的准确性提供可靠性依据。     

Allicin Inhibits Microbial Growth and Oxidative Browning of Fresh-Cut Lettuce (Lactuca sativa) During Refrigerated Storage

Fresh-cut lettuce has a short shelf life since it is very perishable and susceptible to enzymatic browning. The aim of this study was to examine the effectiveness of allicin treatment in prolonging the shelf life of fresh-cut lettuce (Lactuca sativa L. var. angustana Irish). Fresh-cut lettuce slices were treated with water (control), 0.2 and 1 % of allicin solutions, respectively, and stored at 4 °C, >90 % relative humidity. Sensory parameters, microbiological indicators, and physiological indices were determined at 0, 2, 4, and 6 days of storage. The sensory analyses revealed that allicin inhibited the color change and maintained the visual quality of lettuce slice without impairing flavor. Allicin treatment delayed microbial growth at cold storage, as evidenced by the lowered total viable counts (decreased by 2.52 log cfu/g) and yeast and mold counts (decreased by 1.59 log cfu/g) after 6 days in 1 % allicin-treated samples compared to control samples. In addition, differences between lettuce treated with 1 % allicin and control slices in objective color (total color change, chrome, and hue angle), total phenolic compounds and quinones content, activities of browning-related enzymes, and antioxidative enzymes suggested that allicin had antioxidative properties. Conclusively, it was demonstrated for the first time that allicin effectively protected fresh-cut lettuce from tissue browning and microbiological spoilage. These findings indicate that allicin has great potential as a natural additive to extend the shelf life of fresh-cut lettuce.     

Preparation and physicochemical characteristics of an allicin nanoliposome and its release behavior

Allicin, the main active component derived from a traditional flavoring agent - garlic, exerts a variety of biological effects. Unfortunately, its high potential in food processing is limited by its sensibility towards heat and alkaline conditions and its pungent smell. In this research, allicin nanoliposomes were prepared using reverse-phase evaporation method in an attempt to circumvent these shortcomings. The process conditions were optimized by response surface methodology, and the optimal parameters obtained were: lecithin-allicin ratio 3.70:1, lecithin-cholesterol ratio 3.77:1, ultrasonic time 3.40 min, organic phase-aqueous phase ratio 3.02:1. The experimental maximum of entrapment efficiency was 75.20 ± 0.62%, which was consistent with the predictive value (75.05%). Various physicochemical characteristics of allicin liposomes were determined and evaluated. The mean size of allicin nanoliposomes with well-defined spherical shape was 145.27 ± 15.19 nm and only a negligible difference was found after 30 days of storage. The allicin nanoliposomes gave a zeta potential of −40.10 ± 0.96 mV. Based upon the in vitro release profiles, allicin nanoliposomes exhibited a sustained-releasing potential in addition to the release behavior followed the first-order equation. The results indicated that the encapsulation of allicin into liposomes proved to be a promising technology for more widespread application.     

Effect of allicin and its mechanism of action in purine removal in turbot

Low-purine food is not only the focus of gout patients, but also the focus of contemporary green diet development. Fish are usually considered as high-purine foodstuff because of the high nutritional value and high purine content. Therefore, it is necessary to reduce purine content in fish to ensure that they are suitable for patients with hyperuricemia or gout. In this study, the effect of allicin on purine reduction in turbot during cooking was investigated using high-performance liquid chromatography, and the change of xanthine oxidase (XO) activity was also studied. Molecular docking analysis was further performed to elucidate the mechanism of purine reduction by allicin. The results revealed that in the step of soaking, allicin could reduce purine content in fish by slightly enhancing XO activity, promoting hypoxanthine transformation into xanthine. The removal of total purines in experimental and control group reached 70.45% and 57.20%, respectively. Moreover, allicin could change the thermal stability of xanthine by providing an acidic environment, resulting in the rapid decrease of xanthine and hypoxanthine levels by boiling. Thus, this study provides a simple method to decrease purine levels, suggesting a possibility that allicin can function as a purine remover in food.     

HPLC法测定大蒜中蒜氨酸和大蒜素的含量

建立了大蒜中大蒜素和蒜氨酸含量测定的HPLC法。结果表明:蒜氨酸的测定条件为,YMC-PackODS-A C18(25 cm×4.6 mm)色谱柱,流动相为20%甲醇,流速0.7 mL/min,检测波长214 nm;大蒜素的测定条件为,YMC-Pack ODS-A C18(25 cm×4.6 mm)色谱柱,流动相为85%甲醇,流速0.8 mL/min,检测波长214 nm;蒜氨酸和大蒜素的平均回收率分别为,89.9%±1.6%和87.2%±1.3%,精密度(RSD)分别为1.02%和1.46%;大蒜中蒜氨酸和大蒜素的含量分别为,1.67%和0.93%。     

Broad‐spectrum inhibition of proteolytic enzymes by allicin and application in mitigating textural deterioration of ice‐stored grass carp (Ctenopharyngodon idella) fillets

The inhibitory effect of allicin on proteolytic enzymes and textural deterioration of ice‐stored grass carp (Ctenopharyngodon idella) fillets was investigated. The results of in vitro study showed that allicin inhibited the activity of cathepsin B, L and D, calpain and collagenase in crude extract of grass carp muscle. Among endogenous enzymes, cathepsin B, L and collagenase were the most susceptible to allicin. Proteolysis of myofibrillar proteins by either crude enzyme or cathepsin B and L was almost prevented by allicin when employed at a concentration higher than 100 mm . After storage of 21 days, shear force of fillets treated with allicin at 10–100 mm was 39–51% higher than that of control. Myofibrillar proteins of fillets during storage were well protected against degradation when allicin concentration increased to 100 mm , as evidenced by SDS‐PAGE. Therefore, allicin could be a potential broad‐spectrum inhibitor to retard softening of fish fillets via mitigating myofibrillar proteolysis by endogenous enzymes especially cathepsin B and L during ice‐storage.     

藠头皮中蒜素的提取工艺研究

藠头皮是藠头加工过程中的副产物,含有大量的蒜素成分.文章研究了以乙醇为提取剂分离提取蒜素的最佳工艺条件,以萃取温度、萃取时间、乙醇体积分数、料液比值做单因素实验,以萃取温度、萃取时间、乙醇体积分数为试验因子,蒜素含量为响应值,采用响应面法对提取工艺条件进行优化.结果表明:提取温度在26.81℃,乙醇体积分数为90％,萃取时间1.09 h,蒜素含量达到0.906 g/dL,验证值为0.897 g/dL.     

Effect of temperature cycling on allinase activity in garlic

Allinase, which catalyzes the conversion of alliin to allicin, the principal component of potential medicinal value in garlic, is a thermo-labile enzyme. The potential for allicin formation is determined by the quantity of allinase that remains active after the process of preserving garlic by drying. The kinetics of enzymatic activity loss during drying by temperature cycling or by constant temperature were evaluated and compared. Allicin-forming potential was 91% preserved by temperature cycling from 40 to 60 °C. It was found that sugars present in the garlic and the high molecular mass of the enzyme were responsible for protection against degradation at high drying temperatures. Preservation of the enzymatic activity under cyclical conditions occurred mainly with exposure to low temperatures for drying periods longer than those of constant drying conditions.