枫槭叶酶解液美拉德反应及其挥发性成分分析

为了开发新型食用香精,以枫槭叶为原料对枫槭叶酶解后的酶解液在不同温度下进行美拉德反应,然后使用GC-MS分析美拉德反应样品的挥发性成分,采用主成分分析法对挥发性成分进行分析,探讨不同温度下美拉德反应样品的差异及特征成分.结果表明:枫槭叶酶解液与枫槭叶水提取物进行美拉德反应后相比,挥发性物质的种类数和含量都有所增加.GC...     

美拉德反应改善熟化马铃薯冻融酶解汁液风味

以熟化马铃薯冻融酶解汁液为原料,通过添加外源糖类进行美拉德反应,改善其风味。以感官评分和美拉德反应强度为指标,使用单因素结合正交设计法优化酶解汁液反应条件,比较反应前、后汁液中的香气成分、游离氨基酸含量及其体外抗氧化活性变化。结果表明：美拉德反应最优条件为：以木糖和果糖为复配外源糖,质量比1∶3,复配外源糖添加量3.0%,反应体系初始pH 6.0,110℃反应50 min。该条件下制备的马铃薯美拉德反应液挥发性物质种类显著增加,烃类物质、醇类物质含量减少甚至消失,生成较多的糠醛、二甲基丁醛、苯甲醛、苯乙醛等挥发性香气成分及吡嗪、吡啶等坚果香、烤肉香气杂环类化合物;游离氨基酸总含量减少22.52%,鲜味氨基酸和甜味氨基酸相对含量分别提高了2.88%和0.85%,苦味氨基酸相对含量降低了3.72%;美拉德反应汁液体外抗氧化活性增强,总还原力提高3.35倍,DPPH自由清除率和ABTS自由基清除率分别提高了55.82%和33.12%。添加外源木糖和果糖进行美拉德反应可改善马铃薯酶解液风味,增强体外抗氧化活性。     

对虾头酶解液Maillard反应中挥发性成分变化及影响因素

以南美白对虾虾头为原料,经中性酶酶解再经美拉德反应后,应用固相微萃取技术,对原料、酶解液、美拉德反应液中的挥发性物质进行GC-MS分析和比较,并研究反应温度、时间、pH、添加牛磺酸等因素对美拉德反应液挥发性成分的影响。结果表明,原料经酶解再到Maillard反应是一个醇类、醛类、酮类、酯类等物质相对含量减少,吡嗪类等物质生成的过程,且温度升高、反应时间延长、pH值升高及半胱氨酸盐酸盐的添加均能促进此趋势。     

河蚌酶解液美拉德反应前后风味成分的分析

重点研究了河蚌酶解液美拉德反应前后风味成分的变化。利用GC-MS联用法分析、鉴定河蚌肉酶解液和酶解液美拉德反应产物的挥发性风味成分,探讨美拉德反应对河蚌酶解液风味的影响。经NIST2005和Willey7数据库检索和文献对照,两个样品都检出50种成分,主要有醇类、醛类、酮类、酯类和含硫化合物等,他们的协同作用构成了河蚌酶解液及其美拉德反应产物的特征香气;其中河蚌酶解液中含有较多的醛类化合物,而美拉德反应之后则含有较多的醛类和酮类化合物,两样品中均检测出较少的烃类物质,归一化含量分别为2.21%和0.58%。结果表明,美拉德反应能够明显的改善河蚌肉酶解液的风味,所制备的美拉德反应产物具有较好的应用前景。     

美拉德反应改良牡蛎酶解液风味

以牡蛎酶解液为原料,通过美拉德反应对其香气、滋味进行改良。研究还原糖和氨基酸组合、反应温度、反应时间对美拉德反应产物感官的影响,优化美拉德反应条件,并对反应前后的挥发性风味物质进行研究。结果表明,美拉德反应最佳条件为木糖和精氨酸组合, 95%牡蛎酶解液, 2%木糖, 2%味精, 1%精氨酸,在100℃条件下反应90 min。牡蛎酶解液经美拉德反应后,醛类、酸类、含硫类挥发性物质含量明显减少,酯类、吡嗪类、呋喃类、醇类、吡咯类挥发性风味物质含量不同程度地增加,酶解液的风味得到明显改善。美拉德反应改良的牡蛎酶解液与传统蚝汁相比,在海鲜味、肉味、焦糖香上更有感官优势。     

虾蟹漂烫汁酶解液美拉德反应工艺优化及其挥发性物质分析

本文以虾蟹漂烫汁酶解粉末为原料,以感官评价和褐变指数为指标,利用单因素和正交实验,优化美拉德反应工艺,并利用电子鼻和固相微萃取-气质联用技术分析反应前后挥发性物质的变化规律。实验结果表明,美拉德反应的最佳参数为:以虾蟹漂烫汁酶解液为基准,分别添加木糖4%,精氨酸3%,pH7.5,反应时间50 min,反应温度90℃,所得反应产物的感官评分为8.23分,褐变指数为0.7283。在此条件下,电子鼻分析结果表明,美拉德反应后,产品增加了烧烤味和海鲜风味;固相微萃取-气质联用技术分析结果表明,美拉德反应后,产品的胺类、烷烃类、醇类、醛类和酚类等挥发性风味成分明显减少,吡嗪类、有机酸类、酮类及硫化物等挥发性风味成分明显增加。本研究成果可为虾蟹漂烫汁的高价值开发和大规模生产提供理论依据和技术支持。     

美拉德反应型蟹味香精制备条件优化及挥发性风味成分分析

以花蟹酶解液为原料,通过均匀设计实验法,结合感官评价方法,优化美拉德反应型蟹味香精的最佳配方及制备条件,并采用固相微萃取气质联用技术(SPME-GC-MS)研究反应前后的挥发性风味物质组成。研究结果表明,美拉德反应最佳参数为:以花蟹酶解液为基准,分别添加葡萄糖6.7%,木糖2.0%,甘氨酸0.6%,精氨酸2.2%,牛磺酸0.1%,硫胺素1.4%;反应温度101℃,时间33 min,p H7.5。所得反应产物呈均一的红褐色,且香气浓郁,特征风味明显,鲜味醇厚。从花蟹酶解液和反应产物中分别检测出24种和43种风味成分,反应产物中含有酮类8.82%、醛类30.87%、呋喃类18.83%、吡嗪类20.04%、醇类6.35%及一些其他的挥发性风味物质。2,3-丁二酮、3-甲硫基丙醛、2-甲基吡嗪、1-辛烯-3-醇等化合物风味阈值较低,对整体香气具有重要的贡献作用。     

羊肉酶解液美拉德反应工艺优化及其对挥发性风味物质的影响

文章以羊肉酶解液为原料,以A_420nm和感官评分为指标,优化美拉德反应羊肉香精的最佳条件,并采用气相色谱-离子迁移谱联用技术(gas chromatography-ion mobility spectrometry, GC-IMS)研究美拉德反应产物的挥发性风味物质变化。试验结果表明,美拉德反应的最佳添加参数：以羊肉酶解液为基准,反应温度115℃,反应时间120 min,初始pH值8,葡萄糖添加量1.4 g, L-半胱氨酸添加量0.8 g。所得反应产物呈红褐色,具有羊肉特有香气、海鲜风味及烧烤风味。从美拉德反应产物EMH-MRP-A和EMH-MRP-B中共检测出62余种挥发性风味物质,定性的有41余种挥发性风味物质,其中包括醛类17种、酮类10种、烯类4种、醇类3种、呋喃类3种、噻唑类2种、吡嗪类2种、吡啶类1种。2-呋喃甲硫醇、正壬醛、辛酸乙酯、3-甲基丁醛等化合物风味阈值较低,对整体香气具有重要的贡献作用。     

基于豆粕酶解液和脂肪控制氧化技术制备猪肉味香精的研究

以豆粕酶解液为原料,采用气质联用法(GC-MS)、电子鼻法和感官评价法,确定脂肪控制氧化技术制备肉味香精的工艺条件,并分析氧化脂肪对挥发性香气成分的影响。结果表明:肉味香精的最佳工艺条件:脂肪氧化温度130℃,氧化时间2 h,氧化脂肪的添加量5 g/100 mL酶解液;GC-MS和电子鼻分析结果可知,氧化脂肪能有效调控美拉德反应,生成较低量的含硫化合物、糠醛等美拉德反应的典型挥发性香气成分,同时生成大量的醇类、醛类等脂肪降解产物、美拉德反应产物和脂肪氧化降解的相互作用的产物。     

不同方法提取费约果叶片香气成分的比较研究

分别采用索氏抽提法、超声波辅助溶剂萃取法和顶空固相微萃取法对费约果叶片中所含香气成分进行提取,经GC-MS进行分析,结合谱库检索技术,采用峰面积归一化法进行定性和定量分析。结果表明,索氏抽提法所得香气物质中鉴定出挥发性成分20种,占总挥发性成分的70.357%,且以烷烃为主,超声波辅助溶剂萃取法所得香气物质中鉴定出挥发性成分17种,占总挥发性成分的65.222%,且以酯类为主,顶空固相微萃取法所得香气物质中鉴定出挥发性成分最多,有42种,占总挥发性成分的76.899%,且以萜烯类为主。由此可见,在费约果叶片香气成分分析中顶空固相微萃取法能得到最多的香气组分,索氏抽提法次之,超声波辅助溶剂萃取法得到的香气物质最少。     

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.     

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