基于嗅觉指纹信息的黄酒酒龄和产地鉴别

为了找出一种快速、准确鉴别黄酒酒龄和产地的方法,本研究采用超快速气相色谱电子鼻采集不同酒龄和产地黄酒样品的嗅觉指纹信息,采用主成分分析对嗅觉指纹信息进行降维处理,并采用判别因子分类法建立黄酒酒龄和产地鉴别模型。经主成分分析降维后的1年陈和3年陈基酒样品点落在相近的区域内,7年陈和9年陈基酒样品点落在相近的区域内,陈酿时间5年是基酒风味变化的一个转折点;判别因子分类法所建黄酒酒龄鉴别模型的鉴别正确率为100%。主成分分析降维后,绍兴黄酒与上海黄酒、浙江嘉善黄酒和江苏南通黄酒差异明显,进一步采用判别因子分类,4个产地黄酒的鉴别正确率均为100%。研究表明,超快速气相色谱电子鼻结合化学计量学方法建立的模型可以较好地应用于黄酒酒龄和产地的鉴别。     

电子鼻对绍兴黄酒酒龄的判别研究

使用FlashGC型电子鼻代替人工感官品评对黄酒进行酒龄定量研究。结果表明,建立的PLS模型对所选黄酒的酒龄预测结果平行性好,定量准确。适用于大量酒样酒龄的批量判别,结果可信度高。     

The Influence of Yeast Strains on the Volatile Flavour Compounds of Chinese Rice Wine

In order to assess the influence of yeast strains on volatile flavour profiles of Chinese rice wine, small‐scale Chinese rice wine brewing was carried out with eight yeast strains from three different typical Chinese rice wine brewing regions. The volatile flavour compounds were extracted by headspace solid phase microextraction (HS‐SPME) and analyzed by gas chromatography‐mass spectrometry (GC‐MS). The volatile flavour profiles of the different Chinese rice wines showed statistically significant differences depending on the yeast strains used. Yeast strains from the Shaoxing region showed a higher capacity to produce the esters 2‐phenylethanol and 3‐methylthiopropanol, while yeast strains from the Shanghai region stood out for their production of branched‐chain higher alcohols. Chinese rice wine fermented with a yeast strain from the Jiangsu region had the highest levels of organic acids. Using principal component analysis of the Chinese rice wine volatile flavour compounds, the eight yeast strains could be classified into three groups according to their origins. This is the first report about the volatile flavour characteristics of Chinese rice wine yeast. The data obtained in this work shows that the yeast strains contributed significantly to the flavour differences of the Chinese rice wines from the different regions.     

传统发酵江米甜酒中风味香气成分的组成分

以江米为原料，采用民间传统甜酒曲作为发酵剂制备江米甜酒。采用热脱附气相色谱／质谱仪(TCT-GC／MS)测定其挥发性香气成分的组成。结果表明：在江米甜酒中共检测出挥发性香气成分52种，在这些化合物中．醇和酯是两类主要的香气组分，其中酯的种类最多，共17种，占总数的33％；其次是醇，共11种，占总数的21％。其中含量排在前10位的成分依次是：异丁醇、2-甲基丁酸、棕榈酸、乙醇、丙醇、乙酸乙酯、乳酸、11-十六烯酸、肉豆蔻酸和甲酸乙烯酯，占总数的75％，它们构成了江米甜酒的主体香气成分。     

Characterization of Volatile and Semi‐Volatile Compounds in Chinese Rice Wines by Headspace Solid Phase Microextraction Followed by Gas Chromatography‐Mass Spectrometry

The volatile and semi‐volatile compounds of Chinese rice wines were extracted by headspace solid phase microextraction (HS‐SPME) and analyzed by gas chromatography‐mass spectrum (GC‐MS). The original Chinese rice wine samples were diluted with deionized water to a final concentration of 6% (v/v) ethanol and then extracted by HS‐SPME. The samples were pre‐equilibrated at 50°C for 15 min and extracted with stirring at the same temperature for 45 min prior to injection into a GC‐MS. A total of 97 volatile and semi‐volatile compounds were identified from ten Chinese typical rice wine samples, including 13 alcohols, 8 acids, 28 esters, 4 aldehydes and ketones, 17 aromatic compounds, 3 lactones, 6 phenols, 3 sulphides, 9 furans and 6 nitrogen‐containing compounds, of which, 39 compounds were firstly reported in Chinese rice wine. By stepwise linear discrimination analysis, the ten Chinese rice wine samples could be classified into three groups according to the production area, and in particular, the production technologies.     

高效液相色谱法测定黄酒中的β-苯乙醇

建立一种采用反相高效液相色谱法测定黄酒中β- 苯乙醇的方法。采用反相C18 色谱柱Synergi Hrdro-RP C18(4.6mm × 250mm,4μm),以甲醇- 水为流动相(50:50,V/V),流速1ml/min,紫外检测器,检测波长210nm,对黄酒中的β- 苯乙醇进行检测。结果表明,在5.00～30.00mg/L 添加量范围内,回收率水平在99.5%～99.8% 之间,相对标准偏差为0.6% (n = 6),方法的检出限为0.05mg/L,线性范围为0.5～50mg/L(r = 0.9999),测定结果与标准气相色谱方法基本相同。所建立的方法可以作为黄酒中β- 苯乙醇的检测方法。     

中国黄酒中挥发性和不挥发性物质的研究现状与展望

简要回顾了中国黄酒风味成分分析的历史与现状.从微量成分的种类上看,中国黄酒中目前已经检测到的微量成分达100种以上,包括醇类、醛类、酸类、酯类、酚类、含氮化合物,以及其它化合物.近年来,顶空取样、液液萃取、色谱分离技术、固相微萃取等技术已经开始应用于黄酒的风味成分研究.随着先进技术的应用,必将对中国黄酒风味物质以及特征香味成分的研究起到决定性的作用.     

黄酒中陈香物质来源的探讨

利用静态顶空气相色谱分析了陈年黄酒和新酒的香气物质,并对比不同贮存容器中黄酒风味物质的变化,最后对酒样进行感官品评。通过分析比较发现,玻璃瓶中的黄酒贮存5年后,保留了新酒的特殊风味,不具有陈年黄酒的陈香,并且其醇类、酯类物质的含量与陶坛中5年陈的黄酒一致。两种贮存方式中,最大的区别是由于各自所用容器的密封性不同而导致两者氧化速度的巨大差异,玻璃瓶内黄酒中醛类物质的含量远低于普通陈年黄酒。     

不同类型黄酒中杂醇油含量分析及其机制初探

杂醇油是引起黄酒上头的主要因素,严重影响黄酒的品质。该研究建立了外标法顶空进样毛细管气相色谱法测定清爽型黄酒中杂醇油的方法。结果表明方法准确可靠,线性范围为0～1 000 mg/L,样品加标回收率均大于96%,相关系数大于0.998 8,相对标准偏差为1.09%～1.72%。利用该法检测了市场上常见的10种黄酒,结果表明,杂醇油含量最高为528.4 mg/L,最低为152.8 mg/L。杂醇油含量按类型呈现干型<半干型≈半甜型<甜型的特征,初步探明不同工艺会导致黄酒中杂醇油含量的差异。最后通过与其它酒种的比较证实杂醇油是影响黄酒品质的重要因素。     

孝感米酒中乳酸菌的分离及其对黄酒品质的影响

目的:探明孝感米酒中乳酸菌的种类及其对黄酒品质的影响。方法:采用传统可培养方法使用MRS培养基、厌氧工作站,对孝感米酒中乳酸菌进行分离,并接入黄酒对黄酒发酵过程进行干预,进而通过分析黄酒有机酸与滋味等理化特征来评价乳酸菌的发酵特性。结果:从孝感米酒中分离到9株乳酸菌,基于16S rDNA基因对乳酸菌分离株进行了系统发育分析,结果显示它们属于魏斯氏菌属(Weissella)、片球菌属(Pediococcus),种水平上分为戊糖片球菌(Pediococcus pentosaceus)、融合魏斯氏菌(Weissella confusa)、食窦魏斯氏菌(Weissell acibaria)。将这9株菌应用于黄酒发酵制作,在菌株融合魏斯氏菌MJ3-1与MJ4-1、戊糖片球菌MJ6-1、食窦魏斯氏菌MJ8-1干预下,黄酒中乳酸含量显著增加(p<0.05),苹果酸含量显著减少(p<0.05);同时黄酒的滋味中咸味和丰度有显著增加(p<0.05)。总体上来说,乳酸菌对黄酒滋味的影响由酸味、鲜味与丰度引起。结论:融合魏斯氏菌MJ4-1能增加黄酒乳酸,并降低苹果酸含量作用最强,适用于黄酒复合型发酵剂的研发。     

采用气相色谱-离子迁移谱技术检测黄酒风味物质

为实现黄酒中挥发性风味物质的快速无损检测,本研究采用气相色谱-离子迁移谱(Gas chromatography-ion mobility spectrometry,GC-IMS)联用技术结合化学计量学方法对不同酒龄黄酒中的挥发性风味物质进行了研究。黄酒样本的GC-IMS图片库显示,不同酒龄黄酒的挥发性风味物质浓度存在显著差异。采用差谱法从谱图中筛选出33个特征峰,利用其中13个数据库可查询到对应物质的特征峰进行黄酒的风味成分分析。以33个特征峰峰高作为变量,通过主成分分析(principal component analysis,PCA)进行降维,前6个主成分累计贡献率为95%,可以有效区分各组样本。分别采用线性判别(Linear Discriminant Analysis,LDA)、K-最近邻分类算法(K-Nearest Neighbor,KNN)建立酒龄判别模型。结果显示,LDA方法得到的训练集和预测集识别率分别为95%和90%,KNN的判别效果较好,训练集和预测集的识别率均达到100%。这说明,GC-IMS可以有效应用于黄酒挥发性风味物质的检测,在食品风味物质分析等领域具有广阔的应用前景。     

Ferulic Acid Release and 4‐Vinylguaiacol Formation during Chinese Rice Wine Brewing and Fermentation

The release of ferulic acid (FA) and the subsequent enzymatic decarboxylation to 4‐vinylguaiacol (4‐VG) were nearly ubiquitous during the production of Chinese rice wine. To evaluate the release of FA and the transformation to 4‐VG, the levels of FA and 4‐VG were determined by high performance liquid chromatography (HPLC) and gas chromatography‐mass spectrum (GC‐MS), respectively. During rice wine brewing, the concentrations of FA and 4‐VG increased as fermentation time prolonged, with a rapid rise in days 1 to 5 of the main fermentation and followed by a slower rise from the 6th day post inoculation. FA and 4‐VG levels in mashes, fermented by yeast with wheat Qu, were significantly higher than those in mashes fermented by yeast using commercial enzyme additions. The release of FA from rice by wheat Qu involves an enzymatic release mechanism. The levels of FA and 4‐VG from rice flour by wheat Qu rose gradually during the first 24 h and then tended to stabilize. The capacity of yeasts to decarboxylate phenolic acids (Pof⁺ phenotype) was absent in most rice wine brewing yeasts. These results suggest that the production of FA and 4‐VG originated from materials in the wheat Qu rather than by the yeast during Chinese rice wine brewing and fermentation.     

Discrimination Between Shaoxing Wines and Other Chinese Rice Wines by Near-Infrared Spectroscopy and Chemometrics

Shaoxing rice wine (also called Shaoxing wine) is the most well-known Chinese rice wine in China. The common fraudulent practice in the commercialization of Chinese rice wine is to sell wines from different geographical origins under the denomination of Shaoxing rice wine. In this study, the use of near-infrared (NIR) spectroscopy combined with chemometrics as a rapid tool for the discrimination of Chinese rice wine from three geographical origins (“Fujian”, “non-Shaoxing”, “Shaoxing”) has been preliminarily investigated. NIR spectra were collected in transmission mode in the wavelength range of 800–2,500 nm. Discriminant models were developed by principal component analysis (PCA), discriminant analysis (DA), and discriminant partial least-squares analysis (DPLS). The chemical properties of Chinese rice wine were also investigated to find out the difference between samples from three varied origins. The results showed that good classification could be obtained after spectral pre-treatment. The percentage of samples correctly classified by both DA and DPLS methods in calibration and validation set was 97.2% and 100%, respectively. The results demonstrated that NIR could be used as a simple and rapid technique to distinguish Shaoxing wines from non-Shaoxing wines and Fujian wines. To further validate the ability of NIR spectroscopy, more samples should be incorporated to build a more robust model.     

气相色谱指纹图谱法快速鉴别红葡萄酒真假

通过采集10个常见葡萄酒产地中85份真红葡萄酒样品的气相色谱指纹图谱,利用中药色谱图分析和数据管理系统软件进行识别分析,建立了红葡萄酒的气相色谱指纹图谱鉴别葡萄酒真假方法。结果表明,该方法过程仪器的精密度和方法的重现性很好,真红葡萄酒标准指纹图谱包括12个特征色谱峰,其气相色谱指纹图谱峰面积相关系数法、峰面积夹角余弦法、全图谱相关系数法和全图谱夹角余弦法的相似度阈值为≥0.9700。3种方式勾兑的假葡萄酒的试验表明,掺水稀释葡萄酒峰面积的相关系数法和夹角余弦法相似度值都在0.1700以下;葡萄汁勾兑葡萄酒峰面积相关系数法和夹角余弦法相似度值在0.6128以下;人工色素勾兑假葡萄酒峰面积相关系数法和夹角余弦法的相似度值在0.1001以下。通过市售2种可疑葡萄酒的验证试验表明,该2种可疑葡萄酒的峰面积相关系数法和夹角余弦法的相似度值在0.1500以下,低于真红葡萄酒的相似度阈值;且缺少红葡萄酒具有的特征色谱峰,可确定为假葡萄酒。本方法操作简便、快速、客观、准确,是一种值得推广应用的葡萄酒真假的鉴别方法。     

A Study on Characteristic Flavor Compounds in Traditional Chinese Rice Wine — Guyue Longshan Rice Wine

The objective of the study was to systematically investigate flavor compounds in Chinese rice wine (CRW) using chromatography technology. In twelve CRW samples, 93 different flavor compounds were detected and identified including 16 alcohols in addition to ethanol, 29 esters, 9 aldehydes, 9 organic acids, 19 amino acids and 11 fatty acids. Statistical analysis by principal component analysis (PCA) indicated that seventeen flavor compounds in Guyue Longshan rice wine made a large contribution to its special flavor. These compounds were benzaldehyde, acetaldehyde, ethyl 2‐hydroxy‐4‐methylvalerate, ethyl butyrate, phenyl ethyl isobutyrate, ethyl benzoate, ethyl phenyl‐acetate, methyl dodecanoate, methyl oleate, ethyl dedecanoate, 1‐butanol, 3‐ethoxyl‐1‐propanol, 1‐enanthol, dodecanol, lactic acid, fumaric acid and lauric acid.     

Changes in Volatile Compounds of Chinese Rice Wine Wheat Qu During Fermentation and Storage

In order to understand the optimum time of using wheat Qu for Chinese rice wine brewing on the basis of the contents of volatile compounds, changes in volatile compounds of Chinese rice wine wheat Qu during fermentation and storage were studied by headspace solid phase microextraction (HS‐SPME) combined with gas chromatography‐mass spectrum (GC‐MS). It was shown that the concentrations of most groups of volatiles, including alcohols, aldehydes, aromatic compounds, phenols, sulphides, furans, and nitrogen‐containing compounds, increased progressively from the first day to the fourth day of fermentation, and then decreased gradually. A minority group of volatile compounds such as acids and ketones peaked after one day of fermentation, esters increased slowly from the first day to the eighth day of fermentation. Lactones and esters rose slowly from the first day to the fifteenth day of fermentation respectively, and decreased afterwards, whereas the evolution of terpenes was somewhat erratic. These results suggested that changes in the concentrations of most groups of volatile compounds during fermentation and storage were uniform. This made it possible to determine the optimum level of fermentation and storage for Chinese rice wine wheat Qu on the basis of the contents of volatile compounds.     

橡木对黄酒陈化效果的影响

研究橡木片对黄酒陈化效果的影响。选用2012年产的黄酒原酒,分别按0、3、6、9 g/L的添加量向其中加入橡木片。4 个月后对黄酒样品中的风味物质和游离氨基酸进行检测,并进行感官分析。结果表明：添加橡木片处理后,黄酒中高级醇类风味物质的种类和含量均显著减少,醛类风味物质的含量显著增加而种类呈现减少的趋势,酯类风味物质的种类和含量均显著增加（P＜0.05）,说明橡木可促进黄酒的陈化,加快了醇成醛、醇醛成缩醛、醇酸成酯、醛成酸等反应;苦味氨基酸中的苯丙氨酸、苏氨酸、精氨酸、组氨酸和涩味氨基酸中的酪氨酸、缬氨酸的含量均减少;综合黄酒中的风味物质、游离氨基酸变化以及感官评定的结果,表明当橡木片添加量为6 g/L时,贮存4 个月后的黄酒样品已具有较好的陈化效果。     

温度对黄酒酒精度和糖度近红外分析模型的影响

为研究温度对黄酒品质近红外光谱分析模型的影响,分别在5、10、15、20、25、30、35 ℃ 7 个温度条件下采集黄酒样品的可见-近红外光谱,采用偏最小二乘法建立各温度下黄酒酒精度和总糖含量定量分析模型。结果表明：温度对样品光谱存在影响,主成分分析表明不同温度下的样品有明显聚类趋势。模型精度受温度影响较大,但并无随温度变化的一致趋势。建立的混合温度模型预测相对误差较小,有实际应用潜力。     

不同地域黄酒中酸类物质差异性研究

通过高效液相色谱、气相色谱法分别测定了全国不同地区的12种黄酒中的有机酸和游离脂肪酸含量,并以9种有机酸和5种游离脂肪酸为变量进行主成分分析。结果表明:黄酒有机酸中乳酸、乙酸和柠檬酸的含量最高,占总有机酸的80%以上;前4个主成分能代表12种样品中有机酸含量85.276%的信息,因子得分真实地反映了样品的产地、原料、工艺与有机酸的关联性。黄酒中游离脂肪酸种类丰富而且总量差异大,第一主成分、第二主成分累积贡献率达61.783%、83.822%,能够较好地代表原始数据所反映的信息,第一主成分包含C18∶0、C16∶0,第二主成分包含C14∶0、C18∶1,这4种物质对黄酒整体风味的作用可分为三种,即C18∶0和C16∶0、C14∶0、C18∶1。      

Influence of Enzymatic Extrusion Liquefaction Pretreatment for Chinese Rice Wine on the Volatiles Generated from Extruded Rice

Volatile compounds in enzymatic extruded rice, produced under different conditions of varying barrel temperature (BT), α‐amylase concentration (AC) and moisture content (MC), were extracted and identified by headspace solid phase microextraction (HS‐SPME) and gas chromatography‐linked mass spectrometry (GC‐MS). Statistical analyses reflected that the Maillard reaction could be inhibited both by the mild extrusion conditions and the enhanced hydrolysis caused by thermostable α‐amylase. Relative amounts of total volatiles in enzymatic extruded rice were far less than those in severe processed extruded rice. Reverse‐phase high‐performance liquid chromatography (RP‐HPLC) showed that the amino acids (AAs) involved in Maillrad reaction were utmostly preserved in extruded rice with highest amylase concentration by comparison of total AA content of different extrudates. These results suggest that enzymatic extrusion liquefaction is an effective way to control the generation of volatiles from extruded rice for Chinese rice wine production.