制备工艺对柚皮精油产品香味特征及挥发性成分的影响

为阐明制备工艺对柚皮精油产品香味特征及挥发性成分的影响,采用冷磨法、同时蒸馏萃取(SDE)法、超声波辅助萃取法和微波辅助萃取法制备琯溪蜜柚精油,通过感官评价和气-质联用技术(GC-MS)分析它们的香味特征和挥发性成分差异。感官评价表明:冷磨法制备的柚皮精油香味最接近柚皮气味;微波辅助萃取法和超声波辅助萃取法制备的精油气味较接近柚皮香味并带有淡酸味;SDE法制备的柚皮精油味稍辛涩以及具有煮熟柚皮的气味。采用GC-MS技术从各工艺制备的柚皮精油中共检测出91种挥发性成分,鉴定其中的78种成分。虽然4种柚皮精油的主要成分均为d-柠檬烯(63.7%~75.1%)、β-月桂烯(17.2%~28.0%)、β-蒎烯(0.2%~1.3%)、原柚酮(0.6%~1.0%)、α-蒎烯(0.1%~0.3%)和沉香醇(0.1%~0.2%),但是它们的组成有一定的差异。其中,超声波和微波辅助萃取法制备的柚皮精油中酸类、酯类、醛类和高沸点物质(保留指数大于2 000)的含量高于其它工艺制备的精油;SDE法制备的精油中β-月桂烯和萜烯类及其氧化物的含量高于其它工艺制备的精油;冷磨法制备的精油中d-柠檬烯、β-蒎烯、α-蒎烯和醇类化合物的含量高于其它工艺制备的精油。该研究结果表明冷磨法制备的柚皮精油综合品质最好,为柚皮精油的开发利用提供了参考。     

基于气相色谱-质谱/脉冲火焰检测器和主成分分析对不同品种柚汁挥发性风味组分的分析

以5种不同品种柚(琯溪蜜柚、梁平柚、葡萄柚、胡柚、沙田柚)汁为研究对象,采用顶空固相微萃取-气相色谱-质谱/脉冲火焰检测器对柚汁中挥发性组分进行定性和定量分析,并利用气味活性值筛选特征风味组分和主成分分析法区分柚子品种。结果表明,不同品种柚汁中挥发性组分的种类和数量存在不同。在5种柚汁中共鉴定出86种挥发性组分,其中琯溪蜜柚、梁平柚、葡萄柚、胡柚、沙田柚汁中分别检测到34、39、39、32、32种挥发性组分;挥发性组分含量主要以萜烯类、醇类、醛类和酯类为主,挥发性硫化物类含量最低。在5种柚汁中特征风味组分(气味活性值≥1)数量不同：琯溪蜜柚(21)>沙田柚(18)>葡萄柚(16)=梁平柚(16)>胡柚(14);5种柚汁中最主要特征风味组分种类也呈现不同,即琯溪蜜柚(β-紫罗酮)、梁平柚(正己醛)、葡萄柚(柠檬烯)、胡柚(1-辛烯-3-醇)、沙田柚(3-羟基己酸乙酯)。此外,基于柚汁中所有挥发性组分的主成分分析可以明显区分5种不同柚汁品种。不同品种柚汁风味呈现不同,该研究可为加工过程中柚汁原料的选取和未来柚汁风味选育提供理论依据。     

巴氏灭菌对琯溪蜜柚汁挥发性成分及香味的影响

目的:分析琯溪蜜柚汁挥发性成分以及巴氏灭菌对琯溪蜜柚汁香味的影响。方法:采用固相微萃取(SPME)结合气相色谱-质谱联用(GC-MS)技术检测新鲜琯溪蜜柚汁及巴氏灭菌后的琯溪蜜柚汁的挥发性成分。结果:在新鲜琯溪蜜柚汁中共检出27种挥发性成分,主要成分是正己醇(173.27μg/L)和反式-3-己烯-1-醇(88.41μg/L)。巴氏灭菌处理使琯溪蜜柚汁中新生成两种成分,即反式-3-戊烯-2-酮和苯乙醛。正己醛、反式-2-己烯醛、庚醛、辛醛、正辛醇、正式氧化芳樟醇、反式氧化芳樟醇、芳樟醇和壬醛的含量显著增加,2-甲基丁酸乙酯的含量显著减小。巴氏灭菌后,主要成分变为正己醇(182.43μg/L)和正式氧化芳樟醇(140.40μg/L)。通过计算和比较香气活性值,发现新鲜琯溪蜜柚汁的香气主要由蘑菇气味、蒸煮味、青草味和花香味等构成。巴氏灭菌琯溪蜜柚汁的总香气强度增加,花香味、青草味和蒸煮味强度提高。这些结果为阐明加工工艺对柚汁风味的影响提供了第1手资料。     

富含柚皮精油的琯溪蜜柚果脯生产工艺研究

柚子是我国重要的柑橘类水果,琯溪蜜柚是一种大规模种植的特色柚类水果.柚皮富含精油,具有清新的香气及多种保健功能.该研究以苦味物质含量及感官评价为指标对盐水浸煮去除琯溪蜜柚柚皮苦味的工艺进行优化,以弹性为指标优化柚皮果脯糖液配方,并采用顶空固相微萃取结合气相色谱质谱联用仪(Headspace-solid phase mi...     

琯溪蜜柚花不同生长期挥发油累积规律及挥发性成分变化

目的：探索琯溪蜜柚[Citrus grandis (L.) Osbeck. Cv. ‘Guanximiyou’]花不同生长期的挥发油累计规律及挥发性成分变化规律。方法：采用五点采样法在琯溪蜜柚初花期、盛花期及末花期采集开放状态的花朵,利用蒸汽回流提取的方法测定挥发油得率;采用五点采样法在琯溪蜜柚初花期及盛花期采集3种开放程度不同的花朵,运用顶空GC-MS技术分别进行挥发性成分测定,以此探索其挥发性成分的变化规律。结果：柚花挥发油得率最高的时期为初花期,得率为0.18%,最低的时期为末花期,得率为0.03%。经GC-MS分析得知：初花期Ⅰ级花含有16种挥发性成分,主要成分为烯类化合物,以单萜烯类为主,主要成分为β-蒎烯(55.84%)、β-罗勒烯(20.98%)和桧烯(15.45%),Ⅱ级花含有18种挥发性成分,主要化合物为烯类化合物,以单萜烯类为主,主要成分为β-蒎烯(56.31%)、桧烯(17.95%)和β-罗勒烯(17.52%),Ⅲ级花含有13种挥发性成分,主要化合物为单萜醇类化合物,主要成分为芳樟醇(61.94%)、β-蒎烯(18.66%)和β-罗勒烯(6.91%);盛花期Ⅰ级花含有13种挥发性成分,主要化合物为单萜醇类化合物,主要成分为芳樟醇(71.35%)、β-蒎烯(18.81%)和β-罗勒烯(4.35%),Ⅱ级花含有12种挥发性成分,主要化合物为单萜醇类化合物,主要成分为芳樟醇(88.08%)、β-蒎烯(5.94%)和β-罗勒烯(1.75%),Ⅲ级花含有11种挥发性成分,主要化合物为单萜醇类化合物,主要成分为芳樟醇(89.51%)、β-蒎烯(4.58%)和邻氨基苯甲酸甲酯(2.73%)。结论：柚花挥发油含量在初花期最高,其次是盛花期;PCA主成分分析可知,不同生长期及同一生长期不同开放程度的花,挥发性成分均存在一定差异,为相关产业的发展提供一定的理论依据。     

不同品种柚子海绵层可溶性膳食纤维对酸奶储藏期品质的影响

目的 为探究不同柚子海绵层可溶性膳食纤维 (SDF) 对酸奶品质的影响。方法 以6种柚子 (西柚,琯溪蜜柚,文旦柚,坪山柚,梁平柚,沙田柚) 海绵层SDF和奶粉为主要原料制备柚子海绵层SDF酸奶,未添加柚子海绵层SDF的酸奶为对照组,解析储藏过程中酸奶理化指标和微生物指标的变化规律。结果 储藏15天后,琯溪蜜柚海绵层SDF (GSDF) 酸奶的乳杆菌活菌数 (9.34*10^7 CFU/mL) 和可滴定酸度最高 (107.3 °T),西柚海绵层SDF (XSDF) 酸奶的持水力 (67.8 g/g) 和嗜热链球菌活菌数最高。坪山柚海绵层SDF (PSDF) 酸奶的黏度比其他样品组更高,且其蛋白质下降程度最低。此外,添加柚子海绵层可溶性膳食纤维对酸奶的颜色也有较大影响,梁平柚 ( LSDF) 与沙田柚 (SSDF) 海绵层SDF酸奶色泽影响较小,其他柚子海绵层SDF对酸奶的色泽变化影响较大。结论 添加PSDF,XSDF和GSDF能提高酸奶的黏度,有益活菌数,持水力,是良好的功能性添加剂。     

不同树龄梁平柚果皮精油挥发性成分的差异分析

为探索重庆梁平地区不同树龄的梁平柚果皮精油挥发性成分组成和含量的差异性,采用顶空固相微萃取法结合气相色谱-质谱联用分析鉴定5个不同树龄梁平柚皮精油,并利用偏最小二乘法判别分析和凝聚层级聚类分析对其挥发性成分进行统计分析并找出特征挥发性成分。结果表明:5个不同树龄梁平柚皮精油共分离鉴定出72种挥发性化学成分,其中d-柠檬烯、β-月桂烯、圆柚酮等8种成分相对含量较高(>1%),共占总挥发性成分的83.40%~87.61%;HCA分析法将5个不同树龄段梁平柚皮精油聚类为3类,结合PLS-DA分析结果得出E-2-已烯-1-醇、大根香叶烯B、L-薄荷醇等21个挥发性成分为3类精油的特征性挥发物质。研究结果同时发现不同树龄段梁平柚果皮精油挥发性成分的组成具有一定差异性,呈现出不同的香型特征,这为梁平柚果皮精油差异化开发应用提供了理论参考。     

基于GC-MS和GC-O联用法分析佛手精油关键香气成分

研究佛手精油的挥发性物质和关键香气成分。佛手经水蒸气蒸馏法提取精油,利用气相色谱-质谱(gas chromatography-mass spectrometer,GC-MS)结合气相色谱-嗅闻(gas chromatography-olfactometry,GC-O)技术对挥发性物质和香气成分进行分析。GC-MS-O检测出36种挥发性物质,主要成分为D-柠檬烯(34.69%)、γ-松油烯(20.42%)、β-甜没药烯(4.59%)。采用稀释法和强度法分析发现D-α-蒎烯、D-柠檬烯、β-芳樟醇、别罗勒烯、4-松油醇、α-佛手柑烯具有较大的香气强度;D-α-蒎烯、β-蒎烯、β-罗勒烯、橙花乙酸酯、α-佛手柑烯具有较大风味稀释因子。综合分析认为D-α-蒎烯和α-佛手柑烯是佛手精油的关键特征香味成分。     

琯溪蜜柚蒸馏酒香气特征及风味成分分析

研究由琯溪蜜柚汁所制成的蒸馏酒的品质特征,运用感官检验、气相色谱-质谱（gas chromatographymass spectrometry,GC-MS）联用仪、气相色谱火焰离子化检测-嗅闻（gas chromatography-flame ionization detectorolfactory,GC-FID-O）联用分析琯溪蜜柚蒸馏酒的主要香气轮廓及风味成分。感官分析结果表明,琯溪蜜柚蒸馏酒的主体香气是果香和柑橘香。GC-MS结果共鉴定出40 种挥发性物质,其中醇类8 种,酯类14 种,萜烯类10 种,其他8 种。通过制定标准曲线进行定量分析,发现含量较多的挥发性成分为癸酸乙酯（744.73 μg/L）、己酸乙酯（524.74 μg/L）和月桂酸乙酯（193.42 μg/L）。GC-FID-O分析显示：戊酸乙酯、D-柠檬烯、己酸乙酯是琯溪蜜柚蒸馏酒香气轮廓的主要贡献成分。本实验可为研究琯溪蜜柚蒸馏酒及其他柑橘果酒的香气质量提供参考依据。     

AEDA结合OAVs分析两种薰衣草精油中特征性香气成分

采用气相色谱-质谱联用技术(GC-MS)对两种薰衣草精油(兰花、白花)中的挥发性成分进行分析鉴定,鉴定出78种挥发性成分。通过香气提取物稀释分析法(AEDA)结合气相色谱-嗅闻技术(GC-O)对两种精油进行分析,鉴定出31种香气化合物,其中关键香气的物质有8种(FD≥64),分别是β-罗勒烯、芳樟醇、乙酸芳樟酯、香叶醇、橙花醇、薰衣草醇、乙酸香叶酯和β-月桂烯。在此基础上通过香气活性值(OAV)鉴定出22种特征化合物(OAV1),其中关键香气物质13种(OAV10)。两者共同鉴定出6种关键风味化合物,分别是芳樟醇、β-罗勒烯、香叶醇、乙酸芳樟酯、β-月桂烯和乙酸香叶酯。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

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%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press