枸杞粉喷雾干燥工艺优化研究

采用喷雾干燥法制备枸杞粉,研究麦芽糊精添加量对喷雾干燥工艺中粘壁情况及枸杞粉集粉率、水分含量和流动性的影响。在单因素实验的基础上,以枸杞粉集粉率为响应值,利用响应面法优化进料浓度、进风温度和雾化器转速,同时考察了最优工艺下枸杞粉的集粉率、水分含量和流动性。结果表明:枸杞粉喷雾干燥最优工艺参数为麦芽糊精添加量25%,进料浓度22%,进风温度150℃和雾化器转速270r/s,在最优喷雾干燥工艺参数下得到枸杞粉集粉率为47.55%,水分含量为4.11%和流动性为9.2cm。该研究结果为枸杞粉喷雾干燥工艺的完善提供了一定的参考。     

无籽刺梨粉喷雾干燥工艺优化

为改善刺梨粉喷雾干燥效果,优化喷雾干燥工艺,研究进风温度、进料流量、进料浓度、麦芽糊精添加量对喷雾干燥的影响,分析喷雾干燥条件对刺梨粉产率、含水率和VC含量的影响,并采用正交试验优化喷雾干燥条件。结果表明,进风温度190℃,进料流量6 mL/min,进料浓度25%,麦芽糊精添加量40%条件下,刺梨粉产率57.51%,VC 3 901 mg/100 g,含水率3.86%。研究结果可用于指导高质量无籽刺梨粉的生产,为无籽刺梨综合利用提供参考。     

谷朊粉酶解小肽液的喷雾干燥工艺参数的研究

采用正交试验研究筛选了谷朊粉酶解小肽液的喷雾干燥工艺参数,试验结果表明,其最佳工艺参数为:喷雾干燥系统进口温度120℃、料液温度50℃、料液流速0.10 ml/s,所得谷朊粉小肽粉产品产率为84.73%,产品水分为7.31%.     

椰浆粉喷雾干燥工艺

研究酪蛋白酸钠和麦芽糊精对椰浆粉喷雾干燥的技术可行性。采用激光粒度仪测定椰浆乳液粒径,乳液高度法测定乳液的稳定性,根据椰浆粉得率和水分选择喷雾干燥工艺操作参数,根据椰浆粉得率和感官评分确定其配方。结果显示:喷雾干燥工艺的操作参数为进风温度150℃和蠕动泵转速45 r/min;椰浆粉(脂肪含量50%, 100 g椰浆)配方为3.2 g酪蛋白酸钠和19.8 g麦芽糊精(DE 15～18)。成品松散、流动性好,乳白色有光泽,浓郁椰香味,脂肪、蛋白质和水分含量分别为50.4%, 9.8%和1.3%。此次研究可为喷雾干燥制备椰浆粉提供参考。     

草莓速溶粉喷雾干燥工艺的研究

探究草莓速溶粉的最佳喷雾干燥工艺条件,以草莓为原料,进行草莓速溶粉喷雾干燥工艺优化研究。以草莓速溶粉出粉率为指标,对进样流量、β-环糊精添加量、可溶性固形物含量和进风温度4个因素根据Box-Behnken中心组合试验设计原理进行响应面分析。结果表明:进料流量850 mL/h、β-环糊精添加量0.7%、可固形物含量16%、进风温度180℃、出粉率达到44.27%此条件下喷雾干燥效果最佳。     

青木瓜粉干燥工艺研究

对青木瓜(即番木瓜)粉的干燥工艺进行研究。通过不同干燥方法的应用,生产出质量较好的青木瓜粉,优化青木瓜粉的生产工艺参数。结果表明:在不同的干燥方法干燥应用过程中,喷雾干燥生产的青木瓜粉在口感、水溶性、流动性、粉体颜色等指标较好;青木瓜粉在喷雾干燥生产过程中工艺参数为:进口温度180℃,出口温度90℃;青木瓜粉配方为青木瓜4kg、柠檬酸2g、麦芽糊精30%(青木瓜浆白利糖度的30%)。采用喷雾干燥法生产的青木瓜粉水分为3.91%,木瓜蛋白酶活性达到4100U/g。     

黑莓粉喷雾干燥工艺实验研究

研究了喷雾干燥法生产黑莓粉的加工工艺,对影响喷雾干燥效果和黑莓粉产品品质的因素进行了考察。通过对黑莓粉喷雾干燥出粉率和水分含量影响最大的几个主要指标的单因素实验,选取了几个主要影响因素进行正交实验设计,对黑莓粉喷雾干燥工艺参数优化,结果表明:入料流量是主要的影响因素,其次是入料温度、入料浓度和进风温度。最佳工艺参数为入料浓度40%,入料流量60mL/min,入料温度50℃,进风温度200℃时,在此条件下所得产品出粉率最高,为16.5%,所得产品品质良好。     

包埋技术在速溶紫薯粉饮料生产中的应用

利用微胶囊包埋技术制备速溶紫薯粉,并确定了工艺条件。通过喷雾干燥制取速溶紫薯粉,采用单因素对比试验以及正交试验最终确定喷雾干燥的适宜工艺条件:包埋剂β-环状糊精添加量为总质量的0.25%;喷雾干燥工艺条件为:风速1 m3/min、进料量4 L/h、进口温度为130℃。     

速溶紫薯粉加工的助干剂与喷雾干燥工艺优化

以新鲜紫薯为原料,采用正交试验设计对喷雾干燥助干剂及喷雾干燥工艺参数进行优化,研究了3种助干剂及其添加量对紫薯粉出粉率的影响,3种喷雾干燥条件对紫薯粉的综合影响。助干剂结果表明,当麦芽糊精添加量为60%、β-环糊精添加量为12%、CMC添加量为0.8%时,紫薯粉得率最高;喷雾干燥结果表明,当进口热风温度为180℃、进料量为50 m L/min、喷雾流量为700 L/h时,生产的紫薯粉综合评分最高,所得产品为紫色并有浓郁的紫薯香味。该研究以紫薯为原料采取助干剂与喷雾干燥工艺优化相结合可有效加工速溶紫薯粉。     

青木瓜粉干燥工艺研究

对青木瓜(即番木瓜)粉的干燥工艺进行研究。通过不同干燥方法的应用,生产出质量较好的青木瓜粉,优化青木瓜粉的生产工艺参数。结果表明:在不同的干燥方法干燥应用过程中,喷雾干燥生产的青木瓜粉在口感、水溶性、流动性、粉体颜色等指标较好;青木瓜粉在喷雾干燥生产过程中工艺参数为:进口温度180℃,出口温度90℃;青木瓜粉配方为青木瓜4kg、柠檬酸2g、麦芽糊精30%(青木瓜浆白利糖度的30%)。采用喷雾干燥法生产的青木瓜粉水分为3.91%,木瓜蛋白酶活性达到4100U/g。     

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.