水酶法与热熔法提取大鲵油的精制工艺和品质比较研究

研究水酶法和热熔法提取大鲵油的精制工艺及品质差异。采用风味蛋白酶酶解和热熔提取的大鲵油经0. 2%质量分数80%的磷酸脱胶,1. 5%质量分数为6. 67%氢氧化钠溶液脱酸,4%复合脱色剂脱色,料液比1∶3质量分数2%的茶多酚-酵母复合液脱腥,再经115℃、真空度0. 08 MPa减压脱臭1 h,测定两种大鲵油的理化性质和脂肪酸组成。结果表明:水酶油和热熔油的提取率分别为75. 85%、75. 54%,脱色率分别为42. 83%、33. 61%,经茶多酚-酵母复合液脱腥后的水酶油腥味低于热熔油,精制水酶油符合我国水产行业精制鱼油的一级标准,精制热熔油符合水产行业精制鱼油的二级标准;水酶油中不饱和脂肪酸含量为76. 8%,EPA、DHA含量分别为3. 5%、4. 2%,高于热熔油的。水酶法提取大鲵油的品质优于热熔法制备的大鲵油。     

斑点叉尾(鱼回)鱼皮明胶的风味成分及其脱腥的研究

采用顶空固相微萃取和气质联用技术,分析了斑点叉尾(鱼回)鱼皮明胶的风味成分,比较了活性炭、β-环糊精和酵母3种脱腥剂对明胶的脱腥效果。结果表明:斑点叉尾(鱼回)鱼皮明胶的风味成分主要是一些含有羰基的饱和或不饱和的醛类和酮类;(鱼回)鱼皮明胶腥味最为相关的成分为正己醛、正庚醛、2,4-庚二烯醛、2,6-壬二烯醛。活性炭、β-环糊精和酵母都有一定的脱腥效果,其中活性炭脱腥效果最好。活性炭脱腥前醛、酮种类个数分别为13和6,脱腥后减少为5和4;活性炭脱腥前醛、酮含量为27.89%,脱腥后降至10.92%。尤其与腥味相关的正己醛、正庚醛、2,4-庚二烯醛、2,6-壬二烯醛等成分在脱腥后,均未被检出。     

红毛藻复合脱腥工艺的优化及其挥发性成分GC-MS分析

红毛藻是特色药食两用红藻资源,腥味是限制红毛藻深加工产品开发的关键因素之一。该文对红毛藻复合脱腥加热联用浸泡脱腥剂工艺进行优化,并应用气相色谱-质谱联用（gas chromatography-mass spectrometry,GC-MS）分析脱腥前后挥发性成分。结果表明,复合脱腥可显著降低红毛藻的腥味,最优脱腥工艺为加热温度70℃,加热时间4 h,醋酸浓度3%,醋酸处理时间2.0 h。脱腥前红毛藻含有醇类、烯烃、醛类、酮类、酯类、烷烃类和其它类共7大类46种挥发性成分,其中1-辛烯-3-醇、壬醛、2-壬烯醛、2,4-癸二烯醛和3,5-辛二烯-2-酮为腥味成分;复合脱腥后,挥发性成分由46种变为26种,醇类、醛类和酮类物质明显减少,烷烃类和其它类物质明显增多,上述腥味成分含量除壬醛由44.40μg/g降为37.89μg/g外,其它均降为0。     

大鲵肝茶叶水提液脱腥过程中挥发性有机物的动态变化

目的：探讨茶叶水提液对大鲵肝的脱腥效果。方法：采用感官腥味值结合气相—离子迁移色谱(GC-IMS)分析经茶叶水提液处理不同时间(0,5,10,15,20 min)大鲵肝中挥发性成分的变化。结果：与未脱腥组相比,经茶叶水提液脱腥处理5 min后大鲵肝脏腥味值显著下降(P＜0.05),处理10 min后腥味值基本稳定。不同脱腥时间下大鲵肝样品中共鉴定出32种挥发性有机物,包括10种醇类、8种醛类、5种酯类、5种酮类、3种烯烃类和1种醚类。经脱腥处理后,大鲵肝中醇、烯烃、醚、酯类物质相对含量下降,酮类和醛类物质相对含量增加。通过正交偏最小二乘法判别分析(OPLS-DA)结合变量投影重要性(VIP)筛选出10种潜在特征标志物(VIP＞1),包括4种酮类、2种醇类、2种醛类、1种烯类和1种醚类。随着脱腥时间的延长,蘑菇醇、2-丁酮二聚体、异戊醇单体、2-丁酮单体相对含量呈降低趋势,而正己醛单体、异戊醛单体、丙酮相对含量呈增加趋势。结论：茶叶水提液处理5~10 min能够明显降低大鲵肝腥味,通过GC-IMS技术结合多元统计分析可以对脱腥过程中大鲵肝挥发性有机物进行区分。     

响应面法优化海鲈鱼片脱腥工艺

以海鲈鱼(Lateolabrax japonicas)为研究对象,以从天然产物中筛选的薄荷香精、酵母提取物为脱腥剂,采用单因素实验,分析在(15±2)℃的条件下,料液比、脱腥液浓度、脱腥时间对海鲈鱼片的腥味及感官品质的影响,再通过响应面法对海鲈鱼脱腥工艺参数进行优化。结果表明,酵母提取物与薄荷香精能较好地降低海鲈鱼片的腥味;优化的脱腥工艺为:在(15±2)℃条件下,将刚宰杀好的海鲈鱼片放入脱腥液中,料液比为1∶3(g∶m L),脱腥液中酵母提取物的质量浓度和薄荷香精体积分数分别为1. 0 g/L和0. 01%,脱腥浸泡42 min。感官评价显示,处理后鱼片无腥味,且对鱼片的色泽、质地、新鲜度均无影响。经GC-MS分析得出海鲈鱼片脱腥后风味物质种类基本不变,而己醛、2-己烯醛、庚醛、E-2-壬烯醛、癸醛、3,5-辛二烯-2-酮等腥味物质含量明显降低。     

GC-MS法分析养殖大黄鱼脱腥前后挥发性成分的变化

采用静态顶空进样和气-质联用技术初步鉴定了养殖大黄鱼的挥发性成分组成,结果表明:醛类、酮类和胺类是其主要的腥味成分.通过脱腥处理和风味感官分析,确定了养殖大黄鱼关键性腥味物质为2,4,7-癸三烯醛、4-庚烯醛、2,6-壬二烯醛.经过生物脱腥后这些成分基本被脱除.     

泥鳅不同脱腥方法比较及腥味物质分析

以泥鳅为原料,分别采用乌龙茶、面包酵母发酵和酵母细胞液对其进行脱腥处理,以硫代巴比妥酸（thiobarbituric acid,TBA）值、三甲胺（trimethylamine,TMA）值和感官评价值为评价指标,判断其脱腥效果,筛选出较好的脱腥方法及条件,最后通过气相色谱-质谱联用仪（gas chromatography-mass spectrometry,GC-MS）进行验证并判定泥鳅特殊腥味物质。结果表明：脱腥效果从高到低依次为酵母细胞液法、乌龙茶法、面包酵母发酵法。酵母细胞液法脱腥的适宜条件为25 ℃、1.5 h、pH 6.5;乌龙茶法脱腥的适宜条件为：乌龙茶茶叶质量分数3%、25 ℃、3 h;面包酵母法脱腥适宜条件为35 ℃、0.5 h、pH 6.5。由GC-MS分析结果可知,泥鳅原样及乌龙茶法、酵母法、酵母细胞液法脱腥处理后泥鳅挥发性风味物质分别检测出68、55、55、51 种,醛类物质相对含量分别为73.71%、40.17%、42.66%、39.76%,验证结果与TBA值、TMA值和腥味值的评价结果相一致。泥鳅腥味物质可能是己醛、壬醛、辛醛、E-2-辛烯醛、E-2-壬烯醛、E-2,4-癸二烯醛、庚醛、2,3-辛二酮等。     

发酵法脱腥对豪猪肝挥发性风味的影响

采用顶空固相微萃取和气质联用技术(gas chromatography-mass spectrometer,GC-MS),分析了豪猪肝的挥发性风味成分,采用酵母对豪猪肝进行发酵脱腥处理,以感官评分和电子舌主成分分析为评价指标,通过正交实验优化了发酵脱腥工艺条件,并对发酵前后的风味成分进行比较。优化得到酵母发酵脱腥工艺条件:酵母的添加量为1.2%,发酵温度为35℃,发酵时间为45 min。GC-MS分析结果表明,发酵后,豪猪肝的醛类、酮类等主要挥发性风味物质的种类和含量均大幅度减小,其中主要呈味物质正己醛、2-辛烯醛、2-庚烯醛、1-辛烯-3-酮、1-辛烯-3-醇和2-正戊基呋喃的含量也不同程度地减小,所以酵母发酵法能较好地减少或去除豪猪肝的腥味物质。     

基于GC-IMS和SPME-GC-MS分析柠檬汁对太平洋牡蛎（Crassostrea gigas）酶解液风味的改善作用

目的:探究柠檬汁对牡蛎脂质氧化的抑制作用与改善牡蛎酶解液风味的效果,明确牡蛎酶解液风味改善前后的特征香气差异。方法:采用柠檬汁参与牡蛎水解过程对牡蛎（太平洋牡蛎）不良风味进行改善,利用感官评价、气相色谱-离子迁移谱（GC-IMS）与固相微萃取-气相色谱-质谱（SPME-GC-MS）等技术分析牡蛎酶解液风味改善前后的挥发性化合物,并结合感觉阈值和相对气味活度值（ROVA）对其进行特征性香气分析。结果:GC-IMS技术对牡蛎匀浆液、牡蛎酶解液及柠檬汁脱腥后的牡蛎酶解液中共鉴定出40种挥发性化合物,其中,经柠檬汁脱腥后牡蛎酶解液中新生成了7种具有花香、果香等愉快风味特点的挥发性化合物,它们是:蒎烯、苯甲醇、氧化芳樟醇、十二醛、2-庚酮、2-甲氧基苯酚、乙酸丁酯;减少了6种具有鱼腥味等不愉快特征风味的挥发性化合物含量,分别为（E,E）-2,4-辛二烯醛、庚醛、壬醛、（E）-2-辛烯醛、辛醛、1-辛烯-3醇。SPME-GC-MS技术及ROAV法鉴定分析结果显示,经柠檬汁脱腥处理后烯烃类物质的相对含量由8.37%上升为42.84%,主要增加了月桂烯、D-柠檬烯等柠檬汁的特征挥发性风味成分,1-辛烯-3醇不再作为关键风味成分,具有鱼腥味特点的庚醛和（E）-2-辛烯醛的ROAV值下降,整体不良风味减弱。结论:柠檬汁参与牡蛎水解过程可有效减少牡蛎酶解液的腥味及异味,该方法高效、便捷、安全,可为扩大牡蛎酶解液的应用及推动产业脱腥技术的发展提供有益参考。     

牡蛎酶解过程的成分变化及脱腥初步研究

对牡蛎原浆液、酶解液及其浓缩液的基本营养成分进行分析比较,分别采用了活性炭吸附、β-环状糊精包埋法和酵母发酵法对牡蛎酶解液进行脱腥,研究了温度,时间,pH和脱腥剂用量等对脱腥效果的影响. 结果表明:牡蛎蛋白质、水分含量分别为9. 46%和81. 42%:酶解后,蛋白质和水分含量分别为7. 36%和83. 18%;酶解液浓缩后,蛋白质含量高达52. 55%. 活性炭脱腥效果最优:用量为0. 5%,在pH7. 0、30℃条件下吸附0. 5 h,酶解液基本无腥味,蛋白质回收率可达84. 65%. 促进牡蛎酶解液的推广应用.     

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