美拉德反应产物的制备及在混合油脂微胶囊中的应用

为解决目前油脂微胶囊在高载量条件下包埋效率低、储藏稳定性不佳、粉体流动性能差等问题,本研究以酪蛋白酸钠与低聚异麦芽糖为原料通过湿法制备美拉德反应产物,以其为壁材,通过高压均质和喷雾干燥法对以中链甘油酯为主要组分的混合油脂进行包埋,最后对混合油脂微胶囊理化指标进行分析。通过单因素实验确定了美拉德反应产物制备最佳工艺条件:酪蛋白酸钠浓度为7%(w/v),酪蛋白酸钠与低聚异麦芽糖的比例为1:3(w/w),反应时间为120 min,反应温度为80℃,pH为8.0。在乳化阶段,同时添加2%单甘油脂肪酸酯与1%蔗糖脂肪酸酯,采用40与18 MPa二次均质,制得油脂载量高达68%(w/w)混合油脂微胶囊,其表面油和包埋率分别为3.01%和95.66%,卡尔系数和豪斯比分别为7和1.08。扫描电镜观察混合油脂微胶囊内外结构光滑致密,对混合油脂有良好的保护作用。60℃下贮藏30 d后,混合油脂微胶囊过氧化值仅9.06 mmol/kg,油脂保留率达90.57%。表明美拉德反应产物能有效保护芯材成分,抗氧化性能较强,为工业生产提供一定的工业指导方案。     

ε-聚赖氨酸与葡聚糖美拉德反应初级阶段产物的乳化性研究

采用美拉德干热反应制备ε-聚赖氨酸-葡聚糖共价复合物并制备乳液,通过浊度、粒径及稳定性分析,研究了反应温度、湿度、时间、反应物混合比和pH对共价复合物乳化性及乳化稳定性的影响。褐变程度及接枝度结果表明,ε-聚赖氨酸和葡聚糖发生了美拉德反应。以乳化性改善为主要指标,ε-聚赖氨酸/葡聚糖质量比1∶15,在pH8.5,相对湿度为65%,60℃条件下,干热反应1～3d产物的乳化性及乳化稳定明显改善,反应1d复合物乳化性较好且褐变程度较小,接枝度约26.4%。以乳化稳定性改善为指标,ε-聚赖氨酸/葡聚糖质量比1∶10,反应1d最佳。     

亚麻籽炒籽过程美拉德反应底物变化及其模拟体系产物的抗氧化活性北大核心CSCD

为研究亚麻籽热榨过程中美拉德反应形成的物质类型及其抗氧化效果,以亚麻籽为原料,在120~200℃下炒籽10~30 min并提取亚麻籽油,考察不同炒籽条件下亚麻籽油的氧化稳定性,分析炒籽前后亚麻籽脱脂粉中还原糖和游离氨基酸含量变化,确定美拉德模拟体系的反应底物。以抗氧化活性为指标,对美拉德模拟反应条件进行优化,并考察美拉德反应产物(MRPs)对冷榨亚麻籽油氧化稳定性的影响。结果表明:在180℃条件下炒籽20 min制备的亚麻籽油氧化稳定性最好;美拉德模拟反应的最优条件为葡萄糖与赖氨酸物质的量比3∶1、反应温度180℃、反应时间105 min和葡萄糖与精氨酸物质的量比1∶1、反应温度180℃、反应时间105 min;两种MRPs对冷榨亚麻籽油过氧化值增长没有明显的抑制效果,而对p-茴香胺值的增长有一定的抑制作用。赖氨酸、精氨酸和葡萄糖的美拉德反应对提高热榨亚麻籽油的氧化稳定性起关键作用,其MRPs对冷榨亚麻籽油具有一定的抗氧化作用。     

沙棘油及其微胶囊制品过氧化值的测定与比较

研究建立了微胶囊沙棘油过氧化值的测定方法。测定了微胶囊沙棘油粉末产品的过氧化值为12.9meq/kg,比原料沙棘油的过氧化值上升了0.6meq/kg;同时考察了200d内产品过氧化值的变化。在200d内,沙棘油微胶囊粉末产品的过氧化值仅上升了2.9meq/kg,而同等保藏条件下,原料沙棘油过氧化值最高值已经超过55meq/kg,已完全氧化、酸化,说明了壁材成膜性良好,可以延长沙棘油产品的保质期。     

沙棘籽油微胶囊的制备及氧化稳定性评价

沙棘籽油是一种富含不饱和脂肪酸的功能性油脂,容易氧化变质。本文将添加天然抗氧化剂与微胶囊制备技术相结合,改善沙棘籽油的氧化稳定性,延长货架期。首先测定了沙棘籽油的组成成分,然后以沙棘籽油为芯材,添加经过筛选的天然抗氧化剂L-AP,以辛烯基琥珀酸淀粉钠,酪蛋白酸钠及麦芽糊精等为壁材制备沙棘油微胶囊,并通过65 ℃烘箱加速保藏实验评价其氧化稳定性。结果表明:沙棘籽油中不饱和脂肪酸含量占总脂肪酸的80.6%±2.10%;制备沙棘籽油微胶囊的最佳配方为辛烯基琥珀酸淀粉钠15%、酪蛋白酸钠5%、麦芽糊精5%、抗性糊精30%、甘蔗浓缩汁10%、沙棘籽油30%、异麦芽酮糖5%,并添加3 g/L三聚磷酸钠,包埋率高达91.8%±1.59%;65 ℃烘箱加速保藏实验结果表明,添加抗氧化剂并制备微胶囊能有效提高沙棘籽油的氧化稳定性。     

微胶囊化罂粟籽油鲜味粉的制备及理化分析

以自制的鲜味米渣深度水解蛋白粉（20%）和鱼肉水解蛋白粉（13.8%）为壁材,罂粟籽油为芯材,制备了罂粟籽油微胶囊鲜味粉。产品感官指标优良,包埋率达到99.2%,罂粟籽油微胶囊鲜味粉芯材过氧化值为4.53meq/kg,酸价0.50mgKOH/g,符合食用油的卫生要求。     

烘烤对亚麻籽油理化品质、化学组成和抗氧化活性的影响

亚麻籽油因较高的营养价值而受到消费者的青睐,然而,热加工对亚麻籽油品质的影响仍有待阐明。利用热空气对亚麻籽进行烘烤,研究不同烘烤条件对亚麻籽油理化品质（酸价、过氧化值、色泽）、化学组成（共轭二烯、共轭三烯、类胡萝卜素、生育酚、总酚、美拉德反应产物、脂肪酸组成）以及氧化稳定指数、DPPH、ABTS的影响。结果表明：随着烘烤程度增加,亚麻籽油酸价从0.12 mg KOH/100 g增加至1.79 mg KOH/100 g;过氧化值、共轭二烯先增加后减少;类胡萝卜素、总酚、美拉德反应产物、共轭三烯、氧化稳定指数、DPPH以及ABTS均增加,α-亚麻酸含量随烘烤程度增加略微减少。适度烘烤明显改善了亚麻籽油的品质。本研究结果为亚麻籽及亚麻籽油加工提供数据支撑。     

超声协同美拉德反应对酪蛋白乳化性和凝胶性的影响

讨论了超声波协同美拉德反应对酪蛋白美拉德反应及酪蛋白功能特性的影响。酪蛋白在不同功率超声处理后,与葡萄糖在湿热(95°C)条件下反应2.5 h。结果表明,在超声预处理条件下,反应的褐变程度变化不显著(P≥0.05);中间产物和接枝度显著提高(P0.05),450 W协同美拉德反应处理后中间产物含量和接枝度较未经超声预处理的分别提高了12.05%和29.28%;与未经超声波预处理酪蛋白相比,450 W协同美拉德反应处理酪蛋白的凝胶强度和持水性分别提高了1.16倍和1.39倍;扫描电镜结果表明,超声波协同美拉德反应处理酪蛋白所成凝胶结构较未经超声波预处理的更加均匀紧密,孔径更小;450 W协同美拉德反应处理酪蛋白的乳化活性和乳化稳定性分别提高了62.99%和83.63%;SDS-PAGE图谱表明,超声波协同美拉德反应处理后,酪蛋白分子质量增加,酪蛋白与葡萄糖发生了共价交联。以上结果表明超声波预处理可在一定程度上改善美拉德反应及其产物的特性。     

亚麻籽二酯油乳液制备工艺优化及其微胶囊理化性质分析

为提高亚麻籽二酯油的稳定性和利用率,以抗性糊精和酪蛋白酸钠为复合壁材,单硬脂酸甘油酯(MG)和柠檬酸脂肪酸甘油酯(CITREM)为复合乳化剂,制备亚麻籽二酯油乳液,并进一步采用喷雾干燥法制备亚麻籽二酯油微胶囊。通过单因素实验考察固形物含量、MG与CITREM质量比、乳化剂添加量(以芯材质量计)和载油量对亚麻籽二酯油乳液粒径大小以及稳定性的影响,采用Box-Behnken设计响应面实验优化亚麻籽二酯油乳液的制备工艺,并采用钨丝灯扫描电子显微镜、傅里叶变换红外光谱仪、热重分析仪和体外模拟消化模型等对亚麻籽二酯油微胶囊的性质进行了分析。结果表明：亚麻籽二酯油乳液最佳制备工艺条件为固形物含量50%、MG与CITREM质量比5∶4、乳化剂添加量2.5%、载油量50%,在此条件下亚麻籽二酯油乳液粒径为267.40 nm,亚麻籽二酯油微胶囊包埋率为97.85%;亚麻籽二酯油微胶囊结构完整,整体呈球形,外部无明显损伤,且具有良好的热稳定性和溶解性;亚麻籽二酯油微胶囊在体外模拟胃肠道消化过程中芯材释放率达到84.59%。综上,微胶囊化有利于提高亚麻籽二酯油的稳定性,扩大其应用范围。     

美拉德反应制备兔肉香精工艺及微胶囊化研究

以兔肉为原料,对美拉德反应制备兔肉香精及其微胶囊化工艺进行了研究。通过响应面分析法确定美拉德反应制备兔肉香精的最佳工艺条件,即酶解液含水量为66.2%,pH为7.8,热反应温度为119.0℃,热反应时间为68.2 min。通过正交试验确定兔肉香精微胶囊化的最佳条件为:壁材浓度为11.5%,芯壁质量比为1∶5,均质压力为33MPa,进/出风温度为130℃/63℃。     

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