羊脂肪关键香气成分分析

采用溶剂辅助蒸发装置分离并结合气相色谱-质谱及气相色谱-嗅闻分析加热后羊脂肪的关键香气成分。结果表明：根据谱库检索、保留指数、标准品比对气相色谱-质谱鉴定出58 种化合物,其中含量较高的化合物（＞3 μg/kg）为2,3-丁二醇、乙酸、乙偶姻、丙酸、己酸、2-己醇等。采用稀释法/气相色谱-嗅闻分析检测到37 个气味活性区域,根据谱库检索、保留指数、气味特征和标准品比对,鉴定出37 种气味活性成分,其中风味稀释（flavor dilution,FD）因子较大（log2FD≥4）的化合物有(E,E)-2,4-庚二烯醛、(E)-2-壬烯醛、(E,E)-2,4-辛二烯醛、(E)-2-癸烯醛、(E,Z)-2,4-癸二烯醛、(E,E)-2,4-癸二烯醛、2-庚醇、三甲基吡嗪、4-甲基噻唑、3-甲硫基丙醛、5-甲基-二氢-2(3H)-呋喃酮、4-乙基苯酚,这些化合物是羊脂肪香气的关键成分。研究结果可为羊脂肪的开发利用及羊肉香精的研制提供一定参考。     

固相微萃取结合气相色谱-质谱联用法分析唐山蜂蜜麻糖中重要香气成分

目的建立固相微萃取结合气相色谱-质谱联用测定唐山蜂蜜麻糖中的重要香气成分。方法采用固相微萃取结合气相色谱-质谱联用对其中的挥发性成分进行了提取、分离与鉴定,利用质谱和保留指数进行定性,以6-十一酮为内标进行定量,计算鉴定出来的挥发性成分的香气活性值。结果从唐山蜂蜜麻糖中共鉴定出39种挥发性成分,其中醛类16种,醇类10种,有机酸4种,酯类3种,酮类2种,硫醚2种,其他2种;含量最高的是醛类,其中戊醛与己醛的含量分别为1138.24μg/kg和7045.80μg/kg;通过计算这39种挥发性成分的香气活性值发现有16种成分的香气活性值大于1。结论 (反,反)-2,4-癸二烯醛、己醛、3-甲基丁醛、(反,反)-2,4-壬二烯醛、壬醛、二甲基一硫、2-甲基丁醛、二甲基二硫、2-戊基呋喃的香气活性值较高,它们可能是唐山蜂蜜麻糖的重要香气成分。     

不同来源猪脂挥发性成分比较研究

采用顶空- 固相微萃取法提取猪板油和猪肥油的挥发性成分,用气相色谱- 质谱进行分离鉴定。实验结果显示,两种猪脂中分别鉴定出46 种和27 种挥发性成分。猪板油中的主要挥发性成分是棕榈酸、油酸、己醛、壬醛、辛醛、(E,E)-2,4- 癸二烯醛、(E)-2- 辛烯醛、(E)-2- 壬烯醛、2- 戊基呋喃、(E)-2- 庚烯醛等;而猪肥油中的主要挥发性成分是壬醛、(E)-2- 庚烯醛、2- 十五酮、辛醛、(E,E)-2,4- 壬二烯醛、己醛、2,4- 癸二烯醛、(E)-2- 辛烯醛、1 - 辛醇等。     

不同部位羊油的挥发性风味物质和理化性质比较

为探究不同部位羊油品质特性的差异,以羊肠油、羊肚油和羊腰油为研究对象,分别从挥发性风味物质、理化性质、脂肪酸组成等方面进行分析。结果表明,顶空固相微萃取结合GC-MS共鉴定出87种挥发性成分,包括醛类、酸类、醇类、酯类、酮类、烷烃类和其他类化合物,羊腰油和羊肚油挥发性风味物质总含量(6 922.38、6 536.72μg/kg)显著高于羊肠油(4 046.92μg/kg),利用正交偏最小二乘判别分析可以从挥发性成分上较好区分羊肠油、羊肚油、羊腰油。基于不同部位羊油的25种共有挥发性成分,结合气味阈值得到10个共有的关键性风味物质,分别为庚醛、辛醛、壬醛、癸醛、2-十一烯醛、(E)-2-辛烯醛、(E)-2-壬烯醛、(E)-2-癸烯醛、(E,E)-2,4-癸二烯醛、2-十一酮。羊腰油的熔点、硬度和饱和脂肪酸含量最高,分别为44.2℃、379.6 g、54.29%,与羊肚油和羊肠油差异显著。分析不同部位羊油的品质特点,为羊油的合理利用提供了科学依据和理论基础。     

排骨挥发性成分的分离与鉴定

采用同时蒸馏萃取(SDE)和气-质联用(GC-MS)技术,对3种排骨样品的挥发性风味成分进行提取、定性和定量分析。将其结果通过计算机联机检索,结合保留指数,确定化合物的种类。采用面积归一化法确定相对含量,采用内标法确定挥发性成分在样品中的含量。结果表明,共鉴定出32种化合物,从排骨样品A中检测出29种挥发性成分,从排骨样品B检测出20种挥发性成分,从排骨样品C中检测出29种挥发性成分。3种样品共有的挥发性成分有17种,排骨肉样品与肉骨混合样品共有的挥发性成分有27种,排骨骨样品与肉骨混合样品共有的挥发性成分有19种。醛类化合物的含量最高,其中,含量最高的为(E,E)-2,4-癸二烯醛(A:12.133%,0.119μg/g;B:12.757%,0.183μg/g;C:12.003%,0.088μg/g)和十六醛(A:15.913%,0.156μg/g;B:8.224%,0.118μg/g;C:9.384%,0.069μg/g)。     

GC/MS同时检测聚碳酸酯材料中酚类化合物

建立了快速检测聚碳酸酯塑料包装材料中2-叔丁基苯酚、4-叔丁基苯酚及2,4-二叔丁基苯酚等酚类化合物的气相色谱质谱联用法。样品经正己烷超声萃取离心、浓缩后进行GC/MS测定,外标法定量。结果表明,2-叔丁基苯酚、4-叔丁基苯酚及2,4-二叔丁基苯酚均分别在0.1~100 mg/L范围内线性关系良好;定量限(以信噪比≥10计)为1 mg/kg;在4个加标水平下3种酚类化合物的加标回收率为82.23%~92.31%,相对标准偏差为2.13%~4.76%(n=6)。该方法具有优异的灵敏度和稳定性,满足对聚碳酸酯塑料包装材料中2-叔丁基苯酚、4-叔丁基苯酚及2,4-二叔丁基苯酚等酚类化合物的分析检测和准确定量。     

不同生长年限滇黄精的挥发性成分及香气特征分析

为比较分析不同生长年限滇黄精挥发性成分及香气特征,采用顶空固相微萃取-气相色谱-质谱联用技术对滇黄精样品挥发性成分进行定性和定量分析,结合相对气味活性值（Relative Odor Activity Value,ROAV）构建香气雷达图,比较其挥发性香气物质差异,并用正交偏最小二乘判别法（Orthogonal Partial Least Squares Discrimination Analysis,OPLS-DA）和随机森林（Random Forest,RF）筛选出标志差异性香气物质。结果表明,从不同生长年限滇黄精样品中共鉴定挥发性成分67种,主要包括酯类（18.39%~63.98%）16种、烷烃类（2.22%~20.85%）15种、醛类（18.31%~35.45%）9种、烯烃类（0.46%~2.33%）8种、醇类（2.50%~6.21%）5种和酮类（0.39%~1.31%）4种。ROAV和香气雷达图表明(E,E)-2,4-壬二烯醛、庚酸乙酯、正己醛对滇黄精香气贡献较大,2年生青草香较突出,3、4、5年生脂肪味较突出,而6年生果香和花香更强烈。OPLS-DA和RF结果表明2-丁基-2-辛烯醛、己酸乙酯、辛酸乙酯、庚酸乙酯、正己醛和(E,E)-2,4-壬二烯醛为标志性风味物质。该研究结果揭示了不同生长年限滇黄精的挥发性成分及香气特征差异,为其综合开发利用提供数据支撑。     

基于肉鸡性别的鸡汤挥发性物质主成分分析

利用固相微萃取—气相色谱—质谱(SPME—GC—MS)联用内标法,研究基于肉鸡性别差异的传统鸡汤挥发性物质,并分别进行主成分分析。结果显示:两种鸡汤共检测出挥发性物质78种,其中母鸡肉汤和公鸡肉汤分别为76,67种,含量分别为1 369.84,1 029.61μg/100 m L,主要为醛类、酮类、醇类、烷烃类、酸类和酯类,两者共同含有的挥发性物质为65种。母鸡肉汤和公鸡肉汤中反式-2-己烯醛、(E,E)-2,4-庚二烯醛、十三醛、2-庚酮、正己醇等13种风味物质的含量差异显著(P0.05)。两种鸡汤经主成分分析都得到两种主成分物质,且累计贡献率达100%,但种类和含量差别较大。     

控制热氧化冷榨芝麻油的脂肪酸组成及挥发性

本文采用气相色谱（GC）和固相微萃取-气相色谱-质谱联用（SPME-GC-MS）方法分析了控制热氧化前后冷榨芝麻油的脂肪酸组成和挥发性成分的变化情况。通过相对气味活度值（ROAV）评价各风味物质对芝麻油整体香气的贡献,并结合聚类分析确定控制热氧化后冷榨芝麻油中的关键风味物质。结果显示,样品中的脂肪酸主要有7种,包括3种饱和脂肪酸和4种不饱和脂肪酸,热氧化后冷榨芝麻油中的亚油酸及总不饱和脂肪酸的含量显著降低;柠檬烯和罗勒烯等烃类是冷榨芝麻油中的主要挥发性成分,其含量占风味物质总量的74.6%;热氧化后样品中的挥发性成分增加了10种,总峰面积是冷榨芝麻油风味物质总峰面积的2.68倍,3-甲基丁醛、癸醛、(E,E)-2,4-壬二烯醛、(E,E)-2,4-癸二烯醛等醛类含量高达67.9%,是热氧化样品的主要挥发性成分,其中亚油酸的氧化产物(E,E)-2,4-癸二烯醛是热氧化冷榨芝麻油中最重要的风味物质。     

顶空固相微萃取-气相色谱-质谱联用法分析美藤果油中的挥发性成分

采用顶空固相微萃取法提取美藤果油中的挥发性成分,并通过气相色谱-质谱联用技术对其进行分析鉴定,采用峰面积归一化法确定各成分的相对含量。结果表明:美藤果油中共鉴定出46种挥发性成分,占挥发性成分总量的86.73%,主要有(2E,4E)-2,4-庚二烯醛、(2E,4Z)-2,4-庚二烯醛、乙酰基环己烯、(E,E)-3,5-辛二烯-2-酮、3,5-辛二烯-2-酮、反式-2-戊烯、正己醛、(E)-2-庚烯醛等,以醛类、酮类和烃类化合物为主,并含有少量的醇类和呋喃类化合物。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.