甜玉米汁中类胡萝卜素热降解与其挥发性成分的相关性分析

为探索类胡萝卜素热降解过程中产生的挥发性化合物与甜玉米汁风味品质的关系,采用液相色谱-质谱联用技术和顶空固相微萃取-气相色谱-质谱联用技术分析甜玉米汁中主要类胡萝卜素及挥发性成分的种类,研究热处理前后二者的含量变化,探讨挥发性成分与类胡萝卜素热降解的相关性。结果表明:新鲜甜玉米汁中共鉴定出12种主要类胡萝卜素,随着热处理温度的升高,全反式类胡萝卜素发生氧化降解和顺式异构化,含量逐渐降低,顺式类胡萝卜素含量先增加后减少。未加热和加热处理后甜玉米汁中检测出35种挥发性化合物,热处理后甜玉米汁中二甲基硫醚、1-辛烯-3-醇、甲基庚辛酮、β-紫罗兰酮、P-伞花烃等挥发性成分相对含量均有增加。相关性分析结果发现,β-紫罗兰酮、甲基庚辛酮、柠檬烯、苯甲醛、仲辛酮、P-伞花烃、甲苯、连三甲苯等香味物质与反式类胡萝卜素变化呈显著负相关,其中叶黄素和β-胡萝卜素的贡献最大。因此,类胡萝卜素热降解过程中产生的主要挥发性化合物对甜玉米汁风味的形成具有不可忽视的作用。     

南极磷虾头胸部和腹部挥发性风味成分对比

采用顶空固相微萃取-气相色谱-质谱联用技术分析南极磷虾头胸部、腹部和整虾的挥发性风味成分,结合感觉阈值,利用相对气味活度法评价挥发性风味成分对总体风味的影响程度。结果表明,南极磷虾头胸部的主体风味成分为（E,Z）-2,6-壬二烯醛、3-甲基丁醛、3-甲硫基丙醛、壬醛、苯乙醛、D-柠檬烯、（Z）-4-庚烯醛、二甲基硫醚、辛醛、苯甲醛;南极磷虾腹部主体风味成分为二甲基三硫醚、癸醛、壬醛、3-甲基丁醛、辛醛、二甲基硫醚、D-柠檬烯、（Z）-4-庚烯醛;整虾的主体风味成分则包括二甲基三硫醚、癸醛、（E,Z）-2,6-壬二烯醛、3-甲基丁醛、壬醛、3-甲硫基丙醛、辛醛等物质。     

超高压番茄汁体外消化中活性成分溶出研究

比较不同杀菌工艺对番茄汁中番茄红素和VC的体外消化溶出率的影响。生番茄经破碎制汁后,分别用超高压、热杀菌,考察生鲜汁、超高压杀菌汁、热杀菌汁的番茄红素和VC损失率和在体外消化中的溶出量变化。结果表明,超高压、热杀菌和生鲜番茄汁的初始番茄红素含量分别是12.83,11.69和12.84 mg/100 g,经体外消化(胃消化、肠消化各1 h)后番茄红素溶出量分别是8.08,8.76和6.55 mg/100 g;初始VC含量分别是36.59,24.83和36.43mg/100 g,经体外消化(胃消化、肠消化各1 h)后VC溶出量分别是31.21,17.97和29.95 mg/100 g。超高压汁的番茄红素和VC损失均低于热杀菌汁;热杀菌汁的VC损失严重。经体外消化后,超高压汁中VC溶出量远高于热杀菌汁,番茄红素溶出量接近于热杀菌汁。     

浑浊型生啤酒超高压风味保鲜工艺研究

为保证浑浊型生啤酒的生鲜风味、良好口感,以癸酸乙酯、双乙酰的含量为风味考察指标,采用正交试验优化出最佳浑浊型生啤酒超高压处理条件。结果表明:当压力300 MPa、保压时间15 min、温度25℃时,超高压浑浊型生啤酒的风味最佳。在此条件下,其癸酸乙酯含量为0.817 mg/L,接近未处理生啤酒的0.79 mg/L,显著低于经巴氏杀菌处理的3.76 mg/L;双乙酰含量为0.084 mg/L,较接近未处理生啤酒的0.079 mg/L,显著低于经巴氏杀菌处理的0.127 mg/L。说明,超高压处理可在满足浑浊型生啤酒杀菌效果的同时保留其生鲜风味。     

南极磷虾虾仁与4种海虾虾仁挥发性风味成分对比

以顶空固相微萃取-气质联用技术分析南极磷虾虾仁与4种海虾虾仁(中国明对虾、刀额新对虾、大管鞭虾和日本囊对虾)的挥发性风味成分,并以相对气味活度值法评价挥发性成分对总体风味的贡献程度。经鉴定,磷虾虾仁中相对含量较大的挥发性成分包括二甲基硫醚、苯乙烯、对二甲苯、乙苯、壬醛等。磷虾虾仁关键风味成分为二甲基三硫醚、癸醛、甲硫醇、壬醛、辛醛、二甲基硫醚和(Z)-4-庚烯醛;而1-辛烯-3-醇、乙苯、庚醛、苯甲醛、己醛和D-柠檬烯对总体风味有重要作用。4种海虾虾仁挥发性成分的种类及相对含量均与磷虾虾仁有显著差别,但关键风味成分同样由二甲基三硫醚、甲硫醇、癸醛等含硫化合物和醛类组成。关键风味成分的相似性和重要风味成分的多样性可能是磷虾虾仁与四种海虾虾仁挥发性风味相似但不相同的主因。     

速冻加工过程中慈姑挥发性风味成分分析

为探讨速冻加工对慈姑风味的影响,采用顶空固相微萃取与气相色谱-质谱联用技术,分析烫漂和速冻加工处理过程中慈姑挥发性风味化合物的组分及变化。结果表明：慈姑烫漂和速冻处理后分别检测到33 种和29 种挥发性风味化合物。烫漂慈姑中相对含量较高的为烯类、含硫类、醚类、醛类和醇类等,二甲基硫醚、壬醛、辛醛、己醛、D-柠檬烯、柠檬烯、石竹烯、庚醇、泪柏醚等对烫漂慈姑风味有较大贡献;速冻慈姑中相对含量较高的为烯类、醚类、醛类、醇类和含硫类等,二甲基硫醚、壬醛、辛醛、己醛、庚醛、石竹烯、戊醛、庚醇、苯甲醛、2-戊基呋喃、泪柏醚等对速冻慈姑有较大贡献。慈姑经速冻后降低了对慈姑产生负面影响的风味化合物相对含量,如二甲基硫醚;增加了对风味有较大贡献的化合物种类,有利于风味化合物的保存和改善。     

超高压处理对酱卤鸡腿品质及货架期的影响

为探究超高压处理对酱卤鸡腿品质及货架期的影响,实验设置超高压组处理条件为200、400、600 MPa分别处理10 min和15 min,二次热杀菌组处理条件为80℃/30 min。结果表明:超高压600 MPa/10 min和600 MPa/15 min组汁液损失高于二次热杀菌组;超高压处理中样品亮度值随压强增加先下降后略微上升,除200 MPa/10 min处理组外,二次热杀菌组亮度值和超高压处理组无显著差异;二次热杀菌处理后样品剪切力和黏度大于超高压组;2种杀菌方式处理后样品的硬度都有所减小。超高压处理组中烷烃类和醇类风味物质大于二次热杀菌组,酮类风味物质含量小于二次热杀菌组。超高压能抑制样品中腐败菌的生长,延长产品货架期30 d。超高压处理时间越长、压强越大,对腐败菌的抑制越明显,二次热杀菌效果和600 MPa超高压相当。     

UHT杀菌对绿茶饮料风味的影响研究

研究了UHT杀菌对绿茶饮料风味的影响，通过绿茶饮料在UHT杀菌前、后香气成分的定性．定量分析，说明UHT杀菌在杀死绿茶饮料中的有害及腐败微生物时．不仅可以极大程度地保留产品中的营养成分和风味成分，同时还增加了绿茶饮料的甜香成分．     

热烫对超高压杀菌泡菜风味成分的影响

为了探讨热烫护色对超高压杀菌泡菜风味的影响,将发酵成熟的泡菜置于沸腾泡菜水中热烫1.5 min,真空包装后于550 MPa超高压处理5 min,采用SPME-GC-MS测定泡菜香气成分的变化。结果表明,热烫处理对超高压泡菜的风味成分产生显著影响,与未热烫处理的成熟泡菜及高压杀菌泡菜相比,醇类分别增加43.3%及10.4%;酸类分别减少87.4%及69.1%;酯类分别减少75.9%及53.3%,而异硫氰酸酯类分别增加36.8%及8.3%;硫醚类及二硫化物分别减少43.9%及29.9%。从风味上看,热烫护色处理使超高压泡菜中具有清新风味的芳樟醇、α-松油醇、香茅醇、萜品烯、柠檬醛以及异硫氰酸酯类增加,而具有刺激、异香及脂香气的酸类、α-水芹烯、莰烯、二硫化物、某些烯烃类及其它挥发性化合物减少。总之,热烫使泡菜脂香及异味减少,清新气味增加,从而提高超高压泡菜的香味品质。     

海参蒸煮液营养饮料的研制及其风味分析

本文以海参蒸煮液为主要原料,大米汁为次要原料,并辅以柠檬、玫瑰和红枣,利用感官评价和响应面实验设计相结合的方法,研制出色泽均匀、风味独特的海参蒸煮液营养饮料,并通过GC-MS对该饮料的风味成分进行了鉴定。结果表明,该营养饮料中海参蒸煮液与大米汁的最佳体积比为2∶1,各辅料的最适添加量为柠檬汁0.20%,玫瑰汁15.86%,红枣汁12.40%。饮料中共检出32种挥发性成分,主要为烃类、酸类、吡嗪类及酯类,在所有挥发性成分中姥鲛烷、角鲨烯、十三酸和D-柠檬烯相对含量最高,赋予饮料一种偏向新鲜柠檬样香气的清甜香气。该海参蒸煮液营养饮料的研制能够为海参的综合加工利用提供一定的技术指导,对丰富海参制品的种类具有重要意义。     

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