双歧杆菌微胶囊喷雾干燥工艺的影响因素研究

选择明胶为壁材,以两歧双歧杆菌(Bifidobacterium bifidus)Bbm为实验菌株,采用喷雾干燥的方法制成徽胶囊。研究了喷雾干燥过程中的固形物浓度、进样流量、进风温度、出口温度对微胶囊产率及菌体存活率的影响,确定最佳操作工艺参数为:固形物浓度为3%,进样流量为360 mL/h,进风温度为105℃,出口温度为54～57℃,微胶囊产率为65.7%,活菌存活率为53.5%,活菌数超过1×10~(10)cfu/g。     

真空冷冻干燥与喷雾干燥长双歧杆菌的工艺比较研究

为有效延长双歧杆菌的保存期和耐受性,利用真空冷冻干燥及喷雾干燥法制备活性菌粉。研究两种干燥方法的工艺参数,并对干燥得到的活性菌粉性能进行比较。真空冷冻干燥法制备的长双歧杆菌活性菌粉的活菌数为7.98×109CFU/g、存活率90.9%、含水量3.8%,4℃保藏90d后活菌数为2.5×108CFU/g,菌粉的水溶性好;喷雾干燥法制备的活性菌粉的活菌数为4.4×109CFU/g、存活率82.2%、包埋率71.9%、含水量5.6%,4℃保藏90d后活菌数为4×108CFU/g,菌粉在水中的溶解时间较长。真空冷冻干燥成本较高、操作时间长、菌粉的保藏期较短;而喷雾干燥工艺简单、生产成本低、工作效率高,包埋的菌粉保藏期较长。     

分子包埋喷雾干燥制备酸浆籽油微胶囊的研究

以玉米醇溶蛋白与β-环糊精为复合壁材,采用分子包埋法对酸浆籽油进行喷雾干燥制备微胶囊。在单因素试验的基础上,设计响应面法优化试验,探讨制备微胶囊的最佳工艺参数。结果表明,最佳工艺条件为壁材浓度比1∶18(g/mL)、包埋温度60℃、包埋时间90 min;喷雾干燥条件为进口温度170℃、进料量10 mL/min,酸浆籽油微胶囊包埋率达到88.1%。     

正交试验优化番茄红素微胶囊化工艺

以水溶性大豆多糖为壁材,对喷雾干燥法番茄红素的微胶囊化工艺条件进行优化。通过单因素试验和正交试验考察壁材质量浓度、芯材壁材比、乳化剂含量、喷雾干燥进风口温度、出风口温度对番茄红素微胶囊效率的影响作用,同时用扫描电子显微镜法(SEM)对产品进行了形态观察。结果表明：最优工艺为壁材质量浓度0.28g/mL、芯材壁材比1:7、乳化剂质量分数2%、喷雾干燥进风口温度160℃、出风口温度88℃,所得微胶囊效率为91.8%,此番茄红素微胶囊产品膜结构致密完整。水溶性大豆多糖为壁材喷雾干燥法对番茄红素红素进行微胶囊包埋具有可行性。     

麦醇溶蛋白制备微胶囊化玉米胚芽粉末油脂

以麦醇溶蛋白为微胶囊壁材、玉米胚芽油为芯材,通过响应面分析方法研究乳化剂、油/壁材(V/V)的最佳配比;然后通过正交实验确定喷雾干燥工艺适宜的参数来制备玉米胚芽粉末油脂。结果表明,乳化剂、油/壁材的最佳配比为蔗糖酯1.39%,单甘酯0.11%,油/壁材(V/V)10.49%;喷雾干燥适宜的工艺参数为进风温度165℃、出风温度70℃、进料温度60℃。玉米胚芽粉末油脂的贮藏性得以改善,麦醇溶蛋白作为微胶囊壁材是可行的。     

BP神经网络结合遗传算法优化玫瑰茄火龙果固体饮料工艺条件

以火龙果与玫瑰茄干花提取液为芯材,麦芽糊精、可溶性淀粉、阿拉伯胶为壁材,采用喷雾干燥法制备固体饮料。首先使用单因素实验确定提取液用量和壁材使用量,采用正交设计实验探讨进料温度、进料速度、风机速度3个工艺参数对玫瑰茄火龙果固体饮料喷雾干燥效果的影响;在正交实验的基础上,通过BP神经网络确定预测模型后结合遗传算法对喷雾干燥工艺参数进行寻优,获得火龙果玫瑰茄固体饮料的最佳工艺。喷雾干燥最佳工艺条件为玫瑰茄火龙果提取液质量浓度600 g/L,进风温度131℃,进料速度22 mL/min,风机速度3. 1m3/min,在此条件下得到的玫瑰茄火龙果固体饮料的出粉率为47. 85%,相比正交实验的优化结果 47. 12%,提高了0. 73%。BP神经网络结合遗传算法优化喷雾干燥工艺制备玫瑰茄火龙果固体饮料是可行的,可为农产品的深加工工艺优化提供参考。     

醋酸菌喷雾干燥工艺的研究

研究了醋酸菌喷雾干燥工艺。结果表明,当进风温度为107.7℃、进样速度为11.09mL/min、壁材β-环糊精与阿拉伯胶之比为8.7:1.3、壁材浓度为7.59%时,醋酸菌存活率为23.1%,醋酸菌的活菌数为3.8×109cfu/g。     

苦荞黄酮微胶囊的制备

采用喷雾干燥技术,以阿拉伯胶、β-环状糊精、明胶等为壁材,对苦荞黄酮进行微胶囊化.结果表明:选阿拉伯胶、β-环状糊精(1:1)、明胶(1%)、单甘酯(0.3%)作为苦荞黄酮微胶囊的壁材,可以达到较好的微胶囊效果,并确定芯材与壁材最佳配比为0.1g/g;最佳喷雾干燥工艺条件为:进料固形物浓度为20%,最佳进风温度为180℃,均质压力为30 MPa,产品微胶囊得率及微胶囊化率均可达90%以上.     

V_A棕榈酸酯微胶囊的制备及性能研究

以聚天冬氨酸和明胶为壁材,采用单凝聚结合喷雾干燥法制备VA棕榈酸酯微囊。结果表明,最佳原料配比为:壁材浓度为0.1g/mL;芯材与壁材质量比为1∶4;壁材配比为m(明胶)∶m(聚天冬氨酸)=1∶1;乳化剂用量为1.5%;乙醇与水的体积比为1∶2。最佳微胶囊化工艺参数为:喷雾干燥进口温度为160℃,出口温度为70℃,乳化温度为38℃。经过7d的高温(60℃)加速氧化试验,微囊中VA棕榈酸酯的含量为初始含量的84.3%,较好地增加了VA棕榈酸酯的稳定性。     

粉末化蜂蜜的研制

本研究采用喷雾干燥法来制备粉米化蜂蜜,选用麦芽糊精作为辅料降低蜂蜜的黏度.通过正交试验优化出最佳喷雾干燥工艺参数为进风口温度165℃.进料速率15 mL/min,出风口温度100℃下进行喷雾干燥,最佳配方为蜂蜜与麦芽糊粕质量比为1∶1.2.蜂蜜粉末的容量是0.828±0.005g/ml枷,休止角为26.61±0.09°.     

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.     

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.     

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.