微胶囊化甜橙油在高温下的释放

对采用β- 环糊精法和乳化喷雾干燥法所制备微胶囊化甜橙油在温度 10 0、12 0、14 0、16 0、180和 2 0 0℃下的释放进行了研究 ,利用Avrami’s公式分析了微胶囊化甜橙油在高温下的释放。结果表明 ,2种不同方法所制备的微胶囊化甜橙油由于其制备原理上的不同而使其在高温下的释放存在着一定的差异。     

柑橘萜油微胶囊的开发与制备

以β-环糊精+阿拉伯胶+玉米糖浆为壁材,采用喷雾干燥对柑橘萜油进行微胶囊化,通过正交试验,确定出包裹柑橘萜油的最佳工艺条件为:进风温度200℃,出风温度75℃,芯材∶壁材质量比为1∶50,β-环糊精∶阿拉伯胶∶玉米糖浆质量比为2∶3∶5。并测定了柑橘萜油微胶囊在溶液中的释放性能,为该微胶囊的应用提供了很好的理论指导。     

牡丹籽油微胶囊的制备及特性研究

研究以阿拉伯胶和β-环糊精为壁材,牡丹籽油为芯材,采用喷雾干燥法制备牡丹籽油微胶囊,并对其制备工艺及特性进行研究。结果表明:牡丹籽油微胶囊的最佳制备工艺条件为复合壁材阿拉伯胶与β-环糊精质量比1∶2、芯材与壁材质量比1∶2、乳化液总固形物含量20%;在最佳制备工艺条件下制得的牡丹籽油微胶囊产品颗粒圆整、大小分布均匀、囊壁表面平整光滑,包埋率可达86.32%;牡丹籽油微胶囊在常规的热加工处理过程中结构仍然完整,具有良好的热稳定性;牡丹籽油微胶囊化对牡丹籽油的主要功能成分α-亚麻酸的含量基本没有影响。     

喷雾干燥法制备微胶囊化甜橙油的研究

研究了喷雾干燥法制备微胶囊化甜橙油的工艺条件,以阿拉伯胶和麦芽糊精为壁材,通过正交实验得出了微胶囊化包埋甜橙油的最佳工艺条件,运用此工艺制备的微胶囊甜橙油包埋率可达90.25%,长期贮藏后经检测其易挥发性成分损失很小。     

超声波法制备八角茴香油-β-环糊精微胶囊及其表征分析

为提高八角茴香油的稳定性,采用超声波法制备八角茴香油-β-环糊精微胶囊。以包埋率为评价指标,通过正交试验优化制备工艺,并考察微胶囊的加热释放特性。结果表明,最佳制备工艺为八角茴香油与β-环糊精质量比1∶6(g/g)、超声时间40 min、超声温度50℃、超声功率198 W,在此条件下包埋率为94.21%,载药量为6.93%,平均粒径为2.53μm。超声温度和超声功率的变化对微胶囊包埋率的影响显著。红外光谱、差示扫描量热分析和热重分析证实了微胶囊的形成。释放特性表明,200℃条件下加热120 min,八角茴香油保留率仅剩4.60%,而相同温度和时间条件下,微胶囊中八角茴香油保留率为78.38%,是八角茴香油的17.04倍,八角茴香油被包埋后热稳定性提高。超声波法和饱和水溶液法制备微胶囊相比,载药量相差不大,但超声制备的微胶囊包埋率及收率比饱和水溶液法分别提高7.80%和4.98%;超声制备微胶囊包埋率、收率及载药量比研磨法分别提高14.68%、1.88%和1.85%。超声波法是制备高质量八角茴香油-β-环糊精微胶囊的简便可行方法,八角茴香油被包埋后稳定性提高,有望应用于食品保鲜领域。     

葡萄籽油微胶囊的制备及氧化稳定性研究

研究了葡萄籽油微胶囊的制备工艺及其氧化稳定性,以葡萄籽油为芯材,阿拉伯胶与麦芽糊精为壁材,在复合乳化剂的作用下进行乳化,以喷雾干燥法得到微胶囊产品并测定其氧化稳定性。研究表明阿拉伯胶与麦芽糊精重量比为3∶1,乳化剂浓度为10%,芯壁比为1∶2,温度为45℃,均质速度为12000r/min,乳化时间为12 min时制备得到稳定的葡萄籽油乳液,在进风温度180℃、出口温度80℃、进料速率5mL/min条件下喷雾干燥得到葡萄籽油微胶囊,葡萄籽油微胶囊化效率达到72.56%,60℃条件下贮藏葡萄籽油微胶囊的氧化速率明显降低,贮存性能和抗氧化性显著提高。     

猕猴桃籽油微胶囊的制备及稳定性研究

以猕猴桃籽油为芯材,玉米肽为壁材,吐温-20为乳化剂,采用喷雾干燥法制备微胶囊。优化得到最佳工艺条件为:芯材与壁材配比1∶2(质量比),固形物浓度(质量分数) 15%,喷雾干燥温度160℃,高速乳化剪切转速6 000 r/min。在最佳工艺条件下,猕猴桃籽油微胶囊包埋率为94. 06%。对微胶囊产品进行了理化性质、电镜、红外光谱分析和稳定性研究,表明产品具有良好的溶解性和贮存稳定性。     

GC-MS测定二次包埋法及β-环糊精制备葱油香精微胶囊热稳定性的比较研究

探讨了以葱油香精为芯材,用二次包埋法(复凝聚结合喷雾干燥法)和β-环糊精对其进行微胶囊化,分别在2种方法的最佳工艺条件下制备葱油香精微胶囊。扫描电子显微镜对比观察显示,二次包埋法包埋所得微胶囊产品比β-环糊精法所得产品更具有典型的微胶囊表面特性。GC-MS分析2种产品的热稳定性表明,经二次包埋法制得的微胶囊,高温处理下(200℃,3 min)能够提供葱油香精最大程度的保护。     

紫薯花青素微胶囊工艺的研究

以紫色甘薯为原料,通过紫薯花青素的提取、纯化、制粉等技术制备高纯度花青素粉末,利用微胶囊化技术制备紫薯花青素微胶囊。通过单因素试验和正交优化试验对影响紫薯花青素微胶囊包埋率及产率的因素如壁材的选择、壁材比、喷雾干燥进风口温度和喷雾干燥进料速度等进行优化,研究表明,紫薯花青素微胶囊化产品的最佳工艺条件:以β-环糊精+阿拉伯胶为壁材,壁材β-环糊精与阿拉伯胶比例为5︰3,喷雾干燥进风口温度为190℃,喷雾干燥进料速度为40 mL/min,此条件下紫薯花青素微胶囊的包埋率为91.84%。     

玉米黄色素的微胶囊化和稳定性研究

以超临界CO2流体萃取的玉米黄色素为芯材,辛烯基琥珀酸淀粉酯和β-环糊精为壁材,通过乳化、均质、喷雾干燥等工艺,制备了微胶囊玉米黄色素,并对产品的稳定性进行研究.结果表明,玉米黄色素微胶囊化最佳工艺条件为:辛烯基琥珀酸淀粉酯和β-环糊精比值为1:1、固形物含量为20%、芯壁比为1:10,产品包埋率达88.6%.玉米黄色素对光、热、pH和金属离子的稳定性明显增强.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.