挤压膨化机结构参数对豆粕吸水指数影响的研究

研究了豆粕挤压膨化系统诸参数（物料舍水率、螺杆转速、机筒温度）对其吸水性指数的影响规律和挤压膨化系统最佳参数。试验结果表明，影响试验指标的主要因素是螺杆转速，试验因素主次排列为物料含水率、机筒温度、螺杆转速。其较优组合为物料含水率为17％、机筒温度为130℃、转速为305r／min。     

相关参数对单螺杆挤压机耗电量影响的研究

研究了豆粕挤压膨化系统的相关参数（物料含水率、螺杆转速、机筒温度、模头长径比L／D）对耗电量的影响规律和挤压膨化系统最佳参数。试验结果表明，影响试验指标的主要因素是螺杆转速，试验影响因素主次排列为螺杆转速、模头长径比、物料含水率和机筒温度。其最优组合为转速337r／min、模头长径比7、物料含水率35％、机筒温度140℃。     

改良挤压技术制备低蛋白质构米的研究

以粳米淀粉为原料,使用改良挤压技术制备低蛋白质构米,利用响应面分析法考察加工参数如物料含水率、螺杆转速和机筒温度的变化对低蛋白米质构特性的影响,并且以粳米的质构指标为参考指标,优化低蛋白质构米的制备工艺。结果表明,最优工艺参数为物料含水率35%,螺杆转速30r/min,机筒温度(糊化区温度)120℃,该工艺条件下,低蛋白质构米的硬度为(9 122±244)g,黏性为(-983±49)g.s,弹性为0.67±0.05,接近粳米的质构特性(硬度为(8 996±196)g,黏性为(-627±41)g.s,弹性为0.62±0.03)。同时,与粳米相比,其蛋白质含量非常低,为0.43%±0.01%,而且外观和色泽接近市售粳米,米粒完整,颜色均一,圆润光滑,轮廓分明,米质结构紧密。     

单螺杆挤压机加工工艺参数的优化

对豆粕挤压膨化系统诸参数(物料含水率、螺杆转速、机筒温度)对成本的影响规律和挤压膨化系统最佳参数进行了研究.结果表明,影响实验指标的主要因素是螺杆转速,实验因素主次排列为螺杆转速、机筒温度、物料含水率.其较优组合为:转速295r/min、机筒温度130℃、物料含水率27%.     

挤压膨化机结构参数对豆粕吸水指数影响的研究

研究了豆粕挤压膨化系统诸参数(物料含水率、螺杆转速、机筒温度)对其吸水性指数的影响规律和挤压膨化系统最佳参数。试验结果表明,影响试验指标的主要因素是螺杆转速,试验因素主次排列为物料含水率、机筒温度、螺杆转速。其较优组合为物料含水率为17%、机筒温度为130℃、转速为305r/min。     

结构参数对单螺杆挤压机生产率影响的研究

研究了豆粕挤压膨化系统诸参数(物料含水率、螺杆转速、机筒温度)对生产率的影响规律和挤压膨化系统最佳参数。试验结果表明，主次排列为：螺杆转速、机筒温度、物料含水率。物料含水率26％。影响试验指标的主要因素是螺杆转速，试验因素其较优组合为：转速335r/min、机筒温度123℃。     

结构参数对单螺杆挤压机生产率影响的研究

研究了豆粕挤压膨化系统诸参数 (物料含水率、螺杆转速、机筒温度 )对生产率的影响规律和挤压膨化系统最佳参数。试验结果表明 ,影响试验指标的主要因素是螺杆转速 ,试验因素主次排列为 :螺杆转速、机筒温度、物料含水率。其较优组合为 :转速 335r/min、机筒温度 12 3℃、物料含水率 2 6 %。     

降低挤压杂粮营养工程米黏附性的工艺优化

通过单因素试验和响应面分析确定挤压杂粮营养工程米黏附性的优化工艺参数。结果表明,螺杆转速32.6r/min、机筒温度分布109.3～119.3～129.3℃、物料加水质量分数为22.6%,在此优化条件下,挤压杂粮营养工程米黏附性的优化值为－ 375.278178g·s。验证实验表明,黏附性实验值与优化值接近,且优于市售普通大米(－ 394.678g·s),接近于市售魔芋挤压工程米(－ 346.487g·s),说明该优化结果可靠。通过感官评定,其综合食用品质接近市售普通优质大米,优于市售魔芋挤压工程米。     

相关参数对单螺杆挤压机耗电量影响的研究

研究了豆粕挤压膨化系统的相关参数(物料含水率、螺杆转速、机筒温度、模头长径比L/D)对耗电量的影响规律和挤压膨化系统最佳参数。试验结果表明,影响试验指标的主要因素是螺杆转速,试验影响因素主次排列为螺杆转速、模头长径比、物料含水率和机筒温度。其最优组合为转速337r/min、模头长径比7、物料含水率35%、机筒温度140℃。     

玉米蛋白粉挤压膨化工艺参数优化研究

以单螺杆挤压膨化机为试验设备对玉米蛋白粉进行膨化试验,运用二次通用旋转组合设计试验方法研究了玉米蛋白粉含水率、膨化机螺杆转速和机筒温度对加工后的玉米蛋白粉持水性的影响。结果表明:影响玉米蛋白粉持水性的主要因素是机筒温度,试验因素主次顺序依次为机筒温度、螺杆转速、物料含水率;较优组合为:物料含水率43%、螺杆转速334r/min、机筒温度157℃。     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.