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％。     

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。     

不同烹饪方法对大蒜素影响的研究

在空白试验的基础上,利用定硫法测定经过不同烹饪方法加工后,大蒜中大蒜素的含量。结果如下：油炸大蒜后的大蒜辣素含量0.0677g/100g,蒸制大蒜后的大蒜辣素含量0.0684g/100g,水煮大蒜后的大蒜辣素含量0.0845g/100g,微波加热大蒜后的大蒜辣素含量0.1914g/100g。结论：破坏大蒜素最小的烹饪方法是微波加热法,破坏最大的是油炸烹调法。     

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。     

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...     

利用4-MP测定大蒜中的蒜氨酸

为快速、方便地测定大蒜中的蒜氨酸,以鲜蒜为原料,经去皮、加热、制汁、与4-巯基吡啶(4-MP)反应、324纳米测定其吸光度等处理,测知鲜蒜中蒜氨酸的含量为0.74%～0.92%,变异系数2.4%～8.8%,结果表明,4-MP比色法测定大蒜中的蒜氨酸,简单、快速、方便,可用于鲜蒜与保藏大蒜中蒜氨酸含量的测定。     

大蒜中异黄酮提取工艺研究

目的:试验以大蒜为原料,采用索氏提取法提取大蒜中异黄酮并测定其含量。方法:通过对固液比、乙醇浓度、提取时间、提取温度等单因素试验,确定了最佳单因素水平并应用响应面分析法优化试验,以乙醇为提取剂提取大蒜中异黄酮化合物的最佳工艺条件。采用紫外分光光度法测定大蒜中异黄酮含量。结果表明:最佳提取工艺为固液比1∶30.25、乙醇浓度66.2%、提取时间4.005h、提取温度96.9℃。采用紫外分光光度法测得:试验的回收率为99.05%,精密度为3.572%,大蒜中异黄酮提取率1.858mg/g。结论:应用响应面分析法优化处理大蒜中异黄酮化合物的最佳提取工艺条件,其方法可靠性强,用紫外分光光度法测定大蒜中异黄酮含量方法比较准确、可行。     

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。     

大蒜辣素的微波辅助提取

研究了应用微波辅助提取技术从经过破碎酶解的新鲜大蒜中提取大蒜辣素(allicin)的效果,以水为溶剂,采用分光光度法对提取液中大蒜辣素含量进行检测。考察了微波强度、微波作用时间、液料比3个单因素对提取率的影响,用正交试验设计对提取条件进行了优化,得到的优化条件:微波强度1、微波作用时间5min、液料比40∶1。在此优化的条件下,提取率为1000.5mg/100g新鲜大蒜。同时与溶剂提取方法和超声辅助提取方法进行了比较,结果表明微波辅助提取法提取率比溶剂提取法(324.9mg/100g新鲜大蒜)和超声辅助提取法(316.4mg/100g新鲜大蒜)的提取率高。     

大蒜辣素和阿藿烯的制备工艺研究

目的研究制备大蒜辣素和阿藿烯的化学合成和纯化工艺。方法用过氧化氢氧化烯丙基二硫化物合成大蒜辣素,用液-液萃取法纯化产物。大蒜辣素溶解于甲醇,通过加热生成阿藿烯,再用RP-HPLC纯化产物。结果于20℃将烯丙基二硫化物氧化成大蒜辣素的反应呈零级反应动力学。用液-液萃取方法纯化大蒜辣素,取得较佳纯化效果,纯度可达92.2%(HPLC)。以甲醇为溶剂加热制大蒜辣素,阿藿烯为主要产物,经过RP-HPLC制备,得到纯度为98.8%(HPLC)的阿藿烯。结论以烯丙基二硫化物合成大蒜辣素并进一步合成阿藿烯,易于在实验室开展,此法可用于为研究大蒜及其制品的质量控制和药理研究提供标准物质。     

蒜制品中二氧化硫4种检测方法的比较研究

目的研究比较蒜制品中二氧化硫的检测方法。方法通过应用碘量法、比色法、柱后衍生-高效液相色谱法以及离子色谱法检测蒜制品中二氧化硫的结果进行比较分析。结果鲜蒜和脱水蒜制品的比色法检测结果差异较大。采用比色法(盐酸副玫瑰苯胺法)检测鲜蒜和脱水蒜制品中二氧化硫的结果普遍较高,蒜罐头类的检测结果与其他检测方法的值接近。采用滴定法、高效液相色谱法和离子色谱法的检测结果都较为接近。结论 4种方法都可用于蒜制品中二氧化硫的检测,但比色法不适用于鲜大蒜及脱水蒜制品中二氧化硫的检测。     

马铃薯淀粉包埋脱除大蒜臭味

为了保护大蒜的活性成分和掩盖大蒜的不愉快气味,本研究采用研磨法利用马铃薯淀粉的螺旋结构对大蒜 的有机硫化合物进行包埋,以马铃薯淀粉、大蒜（干基）为原料,用包埋率和脱臭效果为指标优化其脱臭工艺,并 对样品进行结构表征。通过高效液相色谱法测定得到的最佳脱臭条件为：马铃薯淀粉与大蒜（干基）质量比3∶1, 研磨时间2.5 h,在此条件下,所得产品的包埋率为（90.63±1.11）%,感官鉴评得分95 分。通过扫描电子显微镜观 察可知,淀粉颗粒被破坏,呈现团聚结构;X射线衍射仪分析表明淀粉的结晶度降低,傅里叶变换红外光谱和热重 分析结果表明样品具有良好的稳定性;通过气相色谱-质谱联用分析可知,大蒜中11 种有机硫化合物的成分在样品 中被全部检出,说明研磨法能促进马铃薯淀粉包埋新鲜大蒜中的臭味物质,既保留大蒜中有机硫化合物又可以达到 脱臭的目的。     

The Comparison of the Contents of Sugar,Amadori, and Heyns Compounds in Fresh and Black Garlic

Black garlic is produced through thermal processing and is used as a healthy food throughout the world. Compared with fresh garlic, there are obvious changes in the color, taste, and biological functions of black garlic. To analyze and explain these changes, the contents of water‐soluble sugars, fructan, and the key intermediate compounds (Heyns and Amadori) of the Maillard reaction in fresh raw garlic and black garlic were investigated, which were important to control and to evaluate the quality of black garlic. The results showed that the fructan contents in the black garlics were decreased by more than 84.6% compared with the fresh raw garlics, which translated into changes in the fructose and glucose contents. The water‐soluble sugar content was drastically increased by values ranging from 187.79% to 790.96%. Therefore, the taste of the black garlic became very sweet. The sucrose content in black garlic was almost equivalent to fresh garlic. The Amadori and Heyns compounds were analyzed by HPLC‐MS/MS in multiple reaction monitoring mode using the different characteristic fragment ions of Heyns and Amadori compounds. The total content of the 3 main Amadori and 3 Heyns compounds in black garlic ranged from 762.53 to 280.56 μg/g, which was 40 to 100‐fold higher than the values in fresh raw garlic. This result was significant proof that the Maillard reaction in black garlic mainly utilized fructose and glucose, with some amino acids.     

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。     

Antimicrobial and preservative activity of garlic on fresh ground camel meat. I. Effect of fresh ground garlic segments

A method to prolong the shelf-life of fresh camel meat, by the use of fresh garlic as an antimicrobial and preservative agent, has been established. Three storage temperatures (room temperature 20–22°C, incubator 12°C and refrigerator 2–3°C) were used in this investigation. Irrespective of storage temperature, treatments with 5, 10 and 15% (by wt.) of fresh garlic segments, ground with fresh lean camel meat, were found to increase the period of shelf-life, two-, three- and more than four-fold, respectively, compared with the corresponding control samples. After 4 days storage at room temperature, 12 days incubation and 28 days refrigeration, it was found that treatments with 15 and 25% garlic resulted i* complete inhibition of microbial growth with no sign of any organoleptic spoilage of the meat. The treated meat samples were fried for 15 min and found to be acceptable in taste and flavour by the local people in Saudi Arabia.     

Comparison of phenolic acids and flavonoids in black garlic at different thermal processing steps

The phenolic acid and the flavonoid constituents of garlic subjected to different thermal processing steps were examined. Black garlic was produced in a ripening chamber by using a programmed stepwise heating schedule, as follows. Step 1: 90 °C and 100% RH for 34 h; Step 2: 60 °C and 60% RH for 6 h; Step 3: 75 °C and 70% RH for 48 h; Step 4: 70 °C and 60% RH for 60 h; Step 5: 65 °C and 50% RH for 192 h. The results of the present investigations showed that thermal processing affected quantities of each phenolic acid and flavonoid component. The total phenolic content (TPC) and total flavonoid content (TFC) of the garlic subjected to different thermal processing steps were higher than those of fresh garlic. In particular, the black garlic cloves ripened using Step 1 (BG1), black garlic cloves ripened using Step 2 (BG2), black garlic cloves ripened using Step 3 (BG3), and black garlic cloves ripened using Step 5 (BG5) samples exhibited levels of TPC that were higher than the TFC, while the TFC in the fresh garlic (FG) and black garlic cloves ripened using Step 4 (BG4) samples were higher than the TPCs. Hydroxycinnamic acid derivatives were found to be the major phenolic acids of garlic at different processing steps. Among the four major flavonoid subgroups in garlic, flavanols were found at the highest concentrations followed by flavanones and flavones, except in the FG sample.     

Novel quantitative assays for estimating the antimicrobial activity of fresh garlic juice

Novel agar diffusion and broth dilution assays were developed for quantitatively estimating the antimicrobial activity of fresh garlic juice. Bacteria found to be inhibited by garlic juice in agar diffusion assay included two gram-positive and five gram-negative species. Leuconostoc mesenteroides was not inhibited. Escherichia coli B-103 (HB101, with pJH101, ampicillin resistant, 100 microg ml(-1)) was inhibited and chosen as the standard culture for quantitative assays. The agar diffusion assay was based on the slope ratio method, where the slope of dose response for garlic juice was divided by the slope of dose response for methylmethane thiosulfonate (MMTSO2). Juice from fresh garlic varied in activity between 1.76 and 2.31 microg of MMTSO2 per mg of garlic juice. The activity of juice decreased during 11 months of storage of garlic cloves at 5 degrees C from 2.31 to less than 0.1 microg of MMTSO2 per mg of juice. The broth dilution assay also used the E. coli B-103 culture, which permitted selective enumeration of this bacterium when 100 microg ml(-1) of ampicillin was incorporated into the enumerating agar. Selective enumeration was essential since the garlic juice was not sterile and, thus, contained natural flora. Growth of E. coli was unaffected by 0.1%, delayed by 0.25%, and completely inhibited at 0.5 and 2% garlic juice in broth during 24 h of incubation at 37 micro C. The minimum inhibition concentration of garlic juice by broth dilution assay was, thus, estimated to be 0.5%, which is equivalent to 3.46 microg of MMTSO2 per mg of garlic juice by the agar diffusion assay.     

黑大蒜和鲜大蒜中可溶性蛋白成分的比较研究

为探究黑大蒜和鲜大蒜中可溶性蛋白成分的差异,采用研磨浸提、硫酸铵沉淀、凝胶柱层析的方法,获得黑大蒜和鲜大蒜可溶性蛋白;采用阿尔玛蓝（Alamar Blue）法检测其体外抗肿瘤活性,采用牛津杯法检测其抗菌活性,并利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法分析其可溶性蛋白成分的差异。结果表明：从黑大蒜和鲜大蒜中提取的可溶性蛋白均具有抗人肝癌细胞株HepG2的活性,鲜大蒜中可溶性蛋白的抗肿瘤活性高于黑大蒜中可溶性蛋白的抗肿瘤活性,且具有耐热性;鲜大蒜中可溶性蛋白还具有抗大肠杆菌和抗金黄色葡萄球菌的活性,其分子质量在10～55 kD之间;黑大蒜中的可溶性蛋白不具有抗菌活性,其分子质量在10 kD左右。黑大蒜与鲜大蒜的可溶性蛋白在种类上差异较大,在抗人肝癌细胞株HepG2、抗大肠杆菌和抗金黄色葡萄球菌的功能上差异显著。     

A comparative study on the antioxidative and anti‐allergic activities of fresh and aged black garlic extracts

The antioxidative and anti‐allergic activities of fresh and aged black garlic extracts were investigated. The garlic samples were extracted with 70% ethanol (v/v) and the total phenolic content was measured. The antioxidant capacity of extracts was assessed by determining the scavenging activities on 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals, ferricyanide reducing power, ferrous ion‐chelating ability and inhibitory effect on linoleic acid peroxidation. The anti‐allergic activity of extracts was analysed by measuring their inhibitory effects against β‐hexosaminidase release. The aged black garlic exhibited significantly higher phenolic content and greater antioxidative activity than fresh garlic. Both garlic extracts showed strong antioxidant capacity in a dose‐dependent manner. On the other hand, a considerably higher suppression of β‐hexosaminidase release was found in fresh garlic extract at lower concentration compared with that of the black garlic. Results of this study illustrate that ageing of garlic could enhance its antioxidant capacity, but could decrease its anti‐allergic activity.