亚麻籽胶为壁材制备亚麻油微胶囊

选用亚麻籽胶为壁材,采用喷雾干燥法,对亚麻油进行微胶囊化。以微胶囊化效率和含油率为考察指标,考察制备亚麻油微胶囊的影响因素。结果表明:最佳喷雾干燥工艺条件:进风温度170℃,出风温度70℃,雾化器转速24000r/min,进料速度50.41mL/min;最佳微胶囊配方为:壁材与芯材比2:3(m/m)。在此工艺条件下,亚麻油的微胶囊化效率为95.32%,含油率59.48%。     

喷雾干燥法制备银杏油微胶囊的研究

以银杏中主要活性物质类黄酮的微胶囊化效率为考察指标,对银杏油进行微胶囊化处理,探讨喷雾干燥法制备银杏油微胶囊的工艺。结果表明,最佳微胶囊原料配方为：阿拉伯胶与β- 环糊精的比例为1:1(m/m),芯材与壁材的比例为1:3(m/m),料液浓度为25%(m/V),单甘脂为0.1%;最佳喷雾干燥工艺条件为：进料流量30ml/min,进风温度180℃,出风温度80℃。在此工艺条件下微胶囊化银杏油的效率可达到90.66%;制备的银杏油微胶囊为黄色或淡黄色细小颗粒,水分含量2.28%,密度0.82g/cm3,溶解度98.10%,黄酮含量5.73%,包埋效果良好。     

文冠果种仁油的微胶囊化及喷雾干燥条件研究

研究了不同壁材及壁材配比、固形物含量和芯材载量对文冠果种仁油微胶囊化效率的影响,并确定了采用喷雾干燥技术制备文冠果种仁油微胶囊产品的工艺条件。结果表明,文冠果种仁油的微胶囊化最佳配方为:壁材为明胶+蔗糖,二者质量比1∶5,固形物含量20%,芯材载量35%;喷雾干燥的最佳条件为:进风温度175℃,出风温度80℃,进料流量650 mL/h。在最佳工艺条件下获得的文冠果种仁油微胶囊产品感官品质较好,在保持低水分含量(仅为2.49%)的同时,兼具良好的溶解度和储存稳定性。     

响应面试验优化黑果枸杞花色苷微胶囊制备工艺及其稳定性分析

建立喷雾干燥法制备黑果枸杞花色苷微胶囊的方法,考察微囊化前后花色苷的稳定性。通过单因素试验,考察壁材中阿拉伯树胶质量分数、β-环糊精质量分数、芯壁比、进料流速、进风口温度、总固形物含量对黑果枸杞花色苷包埋效率的影响,采用Box-Behnken试验设计和响应面分析优化黑果枸杞花色苷微胶囊的包埋工艺。结果表明,黑果枸杞花色苷微胶囊的最佳制备工艺为:进料转速2 000 r/min、乳化时间10 min、出风口温度80℃、阿拉伯树胶质量分数1%、β-环糊精质量分数50%、进料流速330 mL/h的恒定条件下,选择芯壁比1:2.5(g/g)、进风口温度160℃、总固形物含量22%。黑果枸杞微胶囊包埋效率平均值可达91.01%。黑果枸杞花色苷微胶囊为类似圆球状的、平均粒径(9.16±1.02)μm的玫红色粉末,受光照、空气及温度的影响,明显比微胶囊化前稳定。     

番荔枝子油微胶囊化工艺

对番荔枝子油微胶囊化工艺进行研究。通过喷雾干燥法制备番荔枝子油微胶囊。在单因素试验基础上,采用正交试验法优化番荔枝子油微胶囊化工艺,确定了番荔枝子油微胶囊化工艺最佳条件:单甘酯添加量为1.6%,壁材与芯材比为2.0:1,进风温度为200℃,进料速度为4.0 mL/min。     

紫苏油粉末制备工艺研究

以脱皮、低温压榨紫苏油为芯材,利用乳化和喷雾干燥相结合的方法制备紫苏油粉末.确定的最佳制备工艺条件为:壁材大豆分离蛋白与麦芽糖糊精的比例1:1.2,乳化温度70 ℃,固形物含量25%,芯材壁材比40:100;均质压力50 MPa,均质2次;喷雾干燥进风温度168 ℃,出风温度85℃.该条件下制备的紫苏油粉末微胶囊化效率达95%,表面油含量为1%左右.     

木薯微孔淀粉微胶囊化罗非鱼油技术研究

以自制木薯微孔淀粉和罗非鱼皮胶原蛋白为复合壁材、罗非鱼鱼油为芯材,研究罗非鱼油喷雾干燥制备微胶囊的最佳工艺。结果表明,喷雾干燥用罗非鱼油乳化液的工艺条件为乳化温度55℃、乳化体系pH6.0、均质时间6min、芯材壁材配比1:1.5、罗非鱼皮胶原蛋白质量分数1.1%、乳化剂用量0.15%、固形物质量分数20%、进风温度180℃。依此条件生产的产品,鱼油包埋率达92.1%,微胶囊化效果较满意。     

怀远石榴籽油微胶囊的制备及稳定性研究

以怀远石榴籽油为芯材、麦芽糊精和大豆分离蛋白为复合壁材、大豆卵磷脂为乳化剂,采用喷雾干燥法制备石榴籽油微胶囊。在单因素试验基础上,通过正交试验对工艺条件进行优化。得到的最佳工艺条件为:复合壁材的质量分数10%,麦芽糊精与大豆分离蛋白的配比1∶2(质量比),乳化剂大豆卵磷脂的添加量2.0%,芯材与壁材的配比1∶1.5(质量比),喷雾干燥机进风温度185℃,出风温度75℃,进料速度25 mL/min。在最佳工艺条件下,石榴籽油的微胶囊包埋率可达81.9%。微胶囊化后的石榴籽油稳定性较好。     

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。     

甾醇酯微胶囊制备工艺研究

研究了喷雾干燥法制备微胶囊化甾醇酯的工艺。研究结果表明:微胶囊化甾醇酯的最优乳化条件为:复合乳化剂配比(单甘酯∶蔗糖酯)为1∶9;乳化剂用量0.75%;壁材用量20%;壁材比(变性淀粉∶麦芽糊精)为1∶5;芯材/壁材为0.5。喷雾干燥法制备甾醇酯微胶囊的最佳工艺参数为:进料温度50～60℃、均质压力50 MPa、进风温度180℃、出风温度80℃、喷雾压力180 KPa。在此工艺条件下微胶囊化效率可达77.8%。     

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.     

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.     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.