酱香型白酒中稳定碳/氮同位素的测定

建立了气相色谱/元素分析-稳定同位素比质谱法（GC/EA-IRMS）测定酱香型白酒中碳/氮同位素比值（δ13C和δ15N）。酱香型白酒与丙酮混合后,用GC-IRMS法测定乙醇的δ13C值;酱香型白酒被包样于锡杯中,用EA-IRMS测定酒样的δ15N值。结果表明,该方法能快速准确的测定酱香型白酒中碳/氮同位素比值,准确率和精度均满足测定需求。通过测定20家白酒企业中酱香型白酒的δ13C值和δ15N值,20家酱香型白酒企业中乙醇δ13C值和δ15N值范围分别为-20.279‰～-20.340‰和-1.942‰～-2.288‰。表明本方法前处理简单、测定结果准确,可为酱香型白酒的产地溯源提供重要的数据支撑。     

C、H、O同位素分析在葡萄酒产区鉴别中的应用

为有效鉴别产区葡萄酒,利用点特异性天然同位素分馏核磁共振技术和同位素比质谱仪技术对葡萄酒中C、H和O同位素进行研究。通过收集2010-2012年河北昌黎、山东烟台蓬莱、宁夏贺兰山东麓和河北沙城四大产区的60 个样品,发现（D/H）i、（D/H）ii、R、δ13C、δ18O、酒精体积分数的范围分别为95.68×10－6～99.15×10－6、115.99×10－6～126.39×10－6、2.38～2.59、－28.35‰～－23.00‰、－1.94‰～－0.05‰和11.3%～12.9%,总体上含量范围分布广泛,但同一地区较为集中。研究发现,单一使用任何一种元素都只能区分环境差异很大的地区,当结合3 种元素,采用线性判别分析能100%有效鉴别四大产区葡萄酒。基于沙城产区的数据库和酒精体积分数,结合t检验法,分3 步可判定出产区酒的真实性。待测的5 个盲样中只有1 个样品属于沙城产区的真实葡萄酒。     

利用稳定碳同位素的EA-IRMS分析法研究植物糖浆对蜂蜜的影响

通过稳定碳同位素质谱仪检测混合蜜中掺入蔗糖,混合蜂蜜、紫云英蜂蜜和洋槐蜂蜜等中掺入玉米高转化糖浆后的δ13C值的变化情况.结果表明,C4植物糖蔗糖和玉米糖浆的δ13C值偏离蜂蜜δ13C值较大;C3植物糖甜菜糖和大米麦芽糖的δ13C值与蜂蜜δ13C值较为接近.混合蜜中掺入蔗糖,混合蛮、紫云英蜂蜜和洋槐蜂蜜中掺入玉米高转化糖浆后,其δ13C值随掺入量的增加而增大.蜂蜜中蛋白质的δ13C值基本没有变化.存放2年,蜂蜜的δ13C值基本没有变化.     

液相色谱/元素分析仪-同位素质谱法鉴定蜂蜜 掺假的方法改进

目的改进液相色谱/元素分析仪-同位素质谱法鉴别蜂蜜掺假的方法。方法对现有欧盟标准方法优化液相色谱条件,结合元素分析仪-同位素质谱法,将二糖分离为麦芽糖、蔗糖,提出一个新的参数—麦芽糖、蔗糖δ~(13)C值之差δ~(13)C_(M-S)。结果根据本研究检测113个国内外不同来源纯正蜂蜜样本的数据,提出纯正蜂蜜δ~(13)C值新要求:蜂蜜蛋白质与蜂蜜同位素差值δ~(13)C_(P-H)大于-0.97‰;果糖、葡萄糖δ~(13)C值之差δ~(13)C_(F-G)在-0.60‰至0.56‰范围内;麦芽糖、蔗糖δ~(13)C值之差δ~(13)C_(M-S)在-0.73‰至0.98‰范围内;各个组分δ~(13)C最大差值δ~(13)C_(max)小于2.05‰;根据上述4个参数来确认蜂蜜是否掺假。在日常检测和市场销售的160个样品中,原方法阳性检出率为16.2%,而新方法阳性检出率达21.9%。结论本研究提升了蜂蜜掺假检测能力,此方法的建立更好、更精确打击掺假的同时,也维护消费者权益。     

同位素分析技术在葡萄酒加糖酿造工艺中的应用研究

基于不同植物来源糖发酵后乙醇不同位点D/H同位素含量存在差异的原理,本研究利用点特异性天然同位素分馏核磁共振技术(SNIF-NMR)分析了加糖酿造葡萄酒乙醇分子中同位素的变化,结果表明,当添加蔗糖时,乙醇分子(D/H)Ⅰ含量上升,而R值下降;添加甜菜糖,(D/H)Ⅰ含量下降,而R值上升,乙醇(D/H)Ⅰ含量与添加的糖量呈显著正相关关系,通过测定乙醇分子中甲基位(D/H)Ⅰ的含量,可判断葡萄酒在酿造前是否进行了加糖操作。研究表明,SNIF-NMR方法是一种鉴别葡萄酒加糖种类和加糖量的有效分析技术。     

基于稳定同位素比值鉴别鱼翅干制品的品质

建立了基于元素分析-同位素比值质谱联用技术(EA-IRMS)分析鉴别鱼翅干制品品质的方法。在测定真鱼翅干制品的稳定碳、氮同位素组成的基础上,获得了真鱼翅干制品的δ13C值、δ15N值区间,通过对比待测样品与真鱼翅样品之间的差异,进而对待测样品进行真假鉴别。利用本方法共测定了24份鱼翅样品的碳氮同位素比值,结果发现:真鱼翅和假鱼翅的碳氮同位素比值有着显著差别,真鱼翅样品的δ13C和δ15N值分别分布在-16.553‰~-11.065‰和8.803‰~19.122‰之间;而假鱼翅样品的δ13C和δ15N值范围分别为-18.122‰~-16.507‰和6.253‰~7.313‰。通过碳氮同位素比值这两个指标的综合判定,得到24个鱼翅样品中有11个假鱼翅样品。该方法可简便、快速地鉴别鱼翅干制品的品质,同时可弥补PCR检测技术无法判断用鲨鱼下角料压模而成的鱼翅干制品的局限性。     

梨白兰地中乙醇碳同位素分布特征研究

利用元素分析-稳定同位素比值质谱仪测定梨白兰地原料的糖中δ13C,发酵后用气相色谱-燃烧-同位素比值质谱法分析乙醇中碳稳定同位素比值(δ13C)。结果显示梨的糖中δ13C值分布在-27‰~-25‰,而发酵后的乙醇δ13C集中在-30‰~-27‰,且糖与乙醇的δ13C具有良好的线性正相关关系(R2=0.98);白兰地精馏过程中乙醇出现反蒸汽压分馏效应,但酒体部分(50%vol~80%vol)δ13C值波动较小,重现性较好,且与发酵醪中的δ13C值较一致。模拟实验表明,乙醇δ13C值与玉米酒精含量和蔗糖含量成正相关关系,发酵前添加蔗糖和玉米酒精均会改变产品中乙醇δ13C值,因此碳稳定同位素技术可作为检测白兰地中C4来源的酒精或发酵前C4植物糖掺假的鉴别手段。     

同位素比率质谱技术对蜂蜜掺假的鉴别

本文扩展了同位素比率质谱联用技术的应用,完善了液相色谱联用同位素比率质谱（LC-IRMS）测定蜂蜜中多种糖组分δ13C值的方法。通过对3种糖浆、3种掺糖蜜和纯正蜂蜜测定结果和图谱的多重比较,发现单纯的使用元素分析联用同位素比率质谱(HT-IRMS)进行测定,无法完全鉴别出掺糖蜜,但是结合LC-IRMS的测定结果则能有效的对以上3种方式的掺假进行鉴别。对6种特制蜂蜜进行测定并判定,判定结论与实际制样情况相符。该技术手段丰富了鉴别掺假蜂蜜的方法,具有较强的应用价值。     

基于食醋中乙醇的δ13C值对其真伪鉴别的应用初探

文章新建了液相色谱联用稳定同位素比率质谱(LC-IRMS)对食醋中乙醇δ13C值进行测定的方法。简述了仪器的运行过程,通过对色谱柱的选择,从出峰时间的角度考察了其他组分(糖、酸)对乙醇δ13C值测定的影响,使用蔗糖标准物质标定了高纯CO2参考气的δ13C值并考察了线性范围下的测定重复性。对16批次代表性样品进行测定,分析食醋、食醋沉淀物、食醋中乙醇三者间δ13C值的关系,乙醇的δ13C值基本在-28‰~-31‰,与其余二者的δ13C值范围有所差别,低于食醋的δ13C值,说明了在转化过程中发生了一部分的同位素损失;对市场上常见的多种酒精的δ13C值使用该分析方法进行测定,发现工业酒精、玉米食用酒精、淀粉酒精δ13C值在-10‰~-17‰,大米食用酒精在-29.1‰±1.2‰,高粱食用酒精在-17.6‰±1.3‰,其中仅有大米食用酒精的δ13C值与食醋中乙醇的δ13C值区间重合,其他均能轻易分辨出,通过测定食醋中乙醇的δ13C值或可起到真伪鉴别的作用。     

碳稳定同位素在白酒真实性中的应用

本研究优化了有机溶剂稀释法结合气相色谱-燃烧-同位素质谱仪(GC-C-IRMS)测定白酒中乙醇中碳同位素比值(δ13C)的方法。分析了5种年份原酒、24种市场流通固态法白酒以及14种固液法白酒的δ13C值。结果表明:同系列的年份原浆酒中乙醇δ13C值基本无差异;酒中乙醇δ13C值与酿酒粮食和产地有一定关系;利用δ13C鉴别固液法和固态法白酒具有一定可行性。     

Sensory Differences between Product Matrices Made with Beet and Cane Sugar Sources

Although beet and cane sugar sources have nearly identical chemical compositions, the sugars differ in their volatile profiles, thermal behaviors, and minor chemical components. Scientific evidence characterizing the impact of these differences on product quality is lacking. The objective of this research was to determine whether panelists could identify a sensory difference between product matrices made with beet and cane sugar sources. Sixty‐two panelists used the R‐index by ranking method to discern whether there was a difference between 2 brands of beet and 2 brands of cane sugars in regard to their aroma and flavor, along with a difference in pavlova, simple syrup, sugar cookies, pudding, whipped cream, and iced tea made with beet and cane sugars. R‐index values and Friedman's rank sum tests showed differences (P < 0.05) between beet and cane sugars in regard to their aroma and flavor. Significant differences between the sugar sources were also identified when incorporated into the pavlova and simple syrup. No difference was observed in the sugar cookies, pudding, whipped cream, and iced tea. Possible explanations for the lack of difference in these products include: (1) masking of beet and cane sensory differences by the flavor and complexity of the product matrix, (2) the relatively small quantity of sugar in these products, and (3) variation within these products being more influential than the sugar source. The findings from this research are relevant to sugar manufacturers and the food industry as a whole, because it identifies differences between beet and cane sugars and product matrices in which beet and cane sugars are not directly interchangeable.     

Does Information about Sugar Source Influence Consumer Liking of Products Made with Beet and Cane Sugars?

Beet sugar contains an off‐aroma, which was hypothesized to generate expectations on the acceptability of a product made with beet sugar. Thus, the objective of this study was to assess the impact of information about the sugar source (beet vs. cane) on the overall liking of an orange‐flavored beverage. One hundred panelists evaluated an orange‐flavored powdered beverage mix and beverage made with beet and cane sugars using a 5‐phase testing protocol involving a tetrad test and hedonic ratings performed under blind and informed conditions. Tetrad test results indicated that there was a significant difference (P < 0.05) between the beverage mix made with beet sugar and cane sugar; however, no difference was found between the beverage made with beet sugar and cane sugar. Hedonic ratings revealed the significance of information conditions on the panelists evaluation of sugar (F = 24.67, P < 0.001); however, no difference in the liking was identified for the beverage mix or beverage. Average hedonic scores were higher under informed condition compared to blind condition for all products, possibly because labels tend to reduce uncertainty about a product. Results from this study are representative of the responses from the general population and suggest that they are not affected by sugar source information in a beverage product. Based on concerns with the use of beet sugar expressed in the popular press, there may be a subgroup of the population that has a preconceived bias about sugar sources due to their prior experiences and knowledge and, thus, would be influenced by labels indicating the sugar source used in a product.     

Starch Content in Various Types of Cane Sugars as a Criterion of Quality and Authenticity

Contrary to beet sugar, which on the market is used practically only as white sugar, cane sugar is used in a wide range of products for direct consumption. This article presents results of determination of starch content in different types of cane sugars: raw cane sugar, refined white cane sugar, plantation white sugar, and commercial “unrefined” brown and yellow sugars. The content of starch in various “brown” cane sugars ranged from 74 to 415 mg/kg, while in white sugars its content ranged from 51 to 214 mg/kg. The starch content in cane sugars should be an important criterion for the quality of cane sugars, which allowed to differentiate cane sugars from beet sugar containing no starch.     

甜菜糖不良风味分析评价及控制策略

作为传统的两大食糖产品之一,甜菜糖与甘蔗糖的成分几乎无异,微量的成分差异主要是水分、灰分、色素和一些痕量组分。这些痕量组分的存在会使甜菜糖普遍带有一些不良风味,在实际使用尤其是大宗食品工业客户应用过程中会造成不愉悦的感官体验,严重制约着甜菜糖业的发展,甜菜糖的不良风味主要由多种痕量的挥发性组分组成,其成分及形成机理复杂。本文系统地总结了国内外相关研究,对甜菜糖不良风味的组成成分、分析评价方法、形成机理及其控制策略进行讨论和分析,为食糖生产及应用的相关企业全面了解甜菜糖不良风味问题,制定有效抑制方案提供方向性指导。     

我们国家和省区（广东为例）糖业发展的趋势和前景

本文分三大部分为阐述：第一大部分是全国糖业大局问题，指出最近一个榨季年度糖料种植面积，食糖总产和蔗糖，甜菜糖的比例仍为４：１，同时也归纳出沿海与内地蔗糖生产之比为１：３，甜菜糖生产则为２：３，均一致说明糖业发展逐步西移，并详细分析了其原因所在。     

甘蔗榨汁机设计探讨

针对甘蔗的生产状况和市场的需求,设计了一种家用小型甘蔗榨汁机;介绍了整机结构和工作原理;对甘蔗挤压榨汁的起压角α及上下压辊半径等主要参数、甘蔗榨汁的运动过程进行了分析与讨论;确定了压辊转速ω、起压角α和压辊半径的取值范围。     

红糖、白砂糖、赤砂糖与黑糖的HPLC指纹图谱与化学模式识别

建立红糖、黑糖、赤砂糖与白砂糖的高效液相色谱指纹图谱,并对其进行模式识别。采用Durashell C18-AM亲水性色谱柱（250 mm×4.6 mm,5 μm）进行分析,以乙腈-三氟乙酸为流动相,流速1.0 mL/min,柱温25 ℃,进样量10 μL,检测波长210 nm。并对结果进行化学模式识别（聚类分析、主成分分析和正交最小二乘法判别分析）。结果表明,10 批红糖样品指纹图谱中共有峰为13 个,7 批白砂糖中共有峰为1 个,10 批赤砂糖中共有峰为7 个,3 批黑糖中共有峰为17 个。正交最小二乘法判别分析出6 个主要差异性成分。该方法稳定可靠,可将红糖、黑糖、赤砂糖与白砂糖进行明显区分,从而用于该类食品的质量控制与评价。     

The Fermentation of Beet Sugar Syrup to Produce Bioethanol

Fermentation of sugar or starch‐containing substrates by yeast to produce ethanol for use as a liquid fuel has been an accepted technology for many years. Currently, the most popular substrates are sugar cane molasses and starch from maize or wheat. Interest in renewable liquid fuels is growing and other substrates are now being considered, choice of these depends on local conditions. This paper presents findings from work carried out on syrup from sugar beet, an ideal crop for cultivation in the United Kingdom and parts of Europe. Fermentation of this substrate was found to be successful. The process of backsetting was investigated as a way of reducing water usage and effluent disposal. This was found to have no effect on ethanol production provided compensation was made for increases in gravity caused by glycerol levels. Backsetting was also found to be beneficial to yeast growth. As yeast remain in the fermented substrate, the effect of distillation on yeast cells was also investigated. It was found that dead yeast cells are present in backset and thus persist into subsequent fermentations. This can cause difficulties in viability measurement if the methylene blue method is used.