异丙醇提取稻米油动力学特性

采用溶剂浸出法从米糠中提取油脂,以提油率为指标,对不同工艺条件下稻米油提取过程进行动力学分析,研究溶剂、料液比、提取温度以及辅助处理方法对米糠提油率的影响。结果表明：稻米油提取过程符合菲克第二定律,且该动力学方程能较为准确地模拟溶剂法提取稻米油的过程;提取条件不同时,提油率及提取速率差异较明显。相比无水乙醇和正己烷,异丙醇作为提取溶剂时,米糠总提油率Me和传质系数k均较高。适当地增加溶剂用量、提高提取温度以及动态处理均有助于提高总提油率和传质系数。动态处理增大了油脂扩散的传质驱动力,以异丙醇为溶剂,在提取温度为50 ℃、料液比为1∶7.5、动态处理的条件下,米糠提油率达到90.12%,比静态处理提高了0.54 倍,最大有效扩散系数达到5.172 6×10―12 m2/s。     

乙酸乙酯逆流萃取米糠蜡的研究

以米糠油加工所得副产物米糠蜡糊为原料,进行乙酸乙酯间歇式逆流萃取米糠蜡的研究。得到的最佳萃取条件为:溶剂比3∶1,萃取温度75℃,萃取时间30 min,冷却温度20℃,冷却时间2 h,逆流萃取3次。此工艺所得米糠蜡得率可达70%,纯度为99.0%,熔点76℃。     

有机溶剂法提取米糠油工艺的研究

以市售米糠为原料优化米糠油提取工艺,考察提取过程中的不同有机溶剂、提取温度、提取时间、液料比和干燥时间等因素对米糠油提取率的影响。在单因素试验的基础上,选定提取温度、提取时间、液料比进行响应面分析试验,建立二次回归方程,通过响应面分析得到提取米糠油的优化组合条件。结果表明：以混合溶剂（正己烷/环己烷=4∶1,V/V）为提取溶剂,提取温度70 ℃、提取时间2.0 h、液料比为20∶1（mL∶g）时,米糠油提取率为79.81%。     

超临界二氧化碳萃取米糠油的生产工艺研究

以米糠为原料,对超临界二氧化碳萃取米糠油进行了研究。结果表明,超临界二氧化碳萃取米糠油的较优工艺务件为:萃取压力30MPa,萃取温度42℃,CO2流量为60kg/h,萃取时间60min。在最佳萃取条件下,米糠中脂肪的抽提率达到85.53%(脂肪),米糠毛油中的脂肪含量达94%,而不饱和脂肪酸占总脂肪的71%以上。精炼后的米糠油理化参数均达到国家标准。     

微波辅助萃取米糠油的工艺优化

通过微波辅助提取米糠油。通过单因素试验考察了溶剂种类、微波功率、萃取温度、萃取时间和料液(米糠与溶剂)比对米糠油提取率的影响,并通过正交试验确定了最佳提取工艺参数。结果表明:萃取温度65℃,微波功率600 W,微波处理时间100 s,料液比1∶5,米糠油提取率为19.16%。微波辅助提取法具有提取时间短、效率高、毛油质量好等优点。     

乙醇萃取米糠油脱酸脱蜡工艺研究

为探索高酸值米糠油的脱酸、脱蜡方法,以食用乙醇为萃取剂,对米糠油采用萃取的方法达到脱酸、脱蜡的目的.研究表明其优化工艺是:用95％的乙醇与米糠毛油按2.5∶1体积质量比、连续萃取2次,结果是:米糠油得率为87.59％,产品的酸值为1.21 mgKOH/g,谷维素保留率为87.10％,得到米糠毛油重8.93％的游离脂肪酸和3.48％的蜡,乙醇回收率为90.05％,溶耗酸值比为0.56.用乙醇萃取米糠油脱酸脱蜡工艺相比化学脱酸和物理脱酸工艺,设备投资少,谷维素保留率高,米糠油得率较高,回收了副产品游离脂肪酸和蜡.不足之处是消耗的乙醇较多,产品的酸值达不到一级油标准.     

高酸值米糠油同步脱酸脱蜡工艺

以95%乙醇为萃取剂,采用溶剂法对高酸值米糠原油进行同步脱酸脱蜡,以脱酸率、脱蜡率为指标,通过单因素试验和正交试验优化高酸值米糠油同步脱酸脱蜡工艺条件。结果表明：高酸值米糠油脱酸脱蜡最佳工艺条件为卵磷脂添加量0.15%（以95%乙醇质量计）、萃取时间40 min、萃取温度60 ℃、料液比1∶ 2.5、萃取次数4次,在最佳工艺条件下米糠油的脱酸率和脱蜡率分别为99.45%和99.86%,精炼得率为65.67%,谷维素、植物甾醇和维生素E保留率分别为87.88%、9764%和95.15%。     

柠檬黄素在淀粉凝胶内的扩散特性研究

测定了在4℃和35℃条件下柠檬黄素在3种浓度的小麦﹑小米淀粉凝胶内的扩散系数。结果表明,在相同条件下,与小麦淀粉凝胶相比,柠檬黄在小米淀粉凝胶内的扩散较慢。扩散系数随着凝胶浓度的减小而增大,随着温度升高而升高。与改变浓度相比,降低温度更能有效地降低柠檬黄在淀粉凝胶内的扩散速度。     

莴笋渗透脱水有效扩散系数研究

以葡萄糖溶液浓度(10%～40%)和温度(35～65℃)为影响因素,研究了莴笋渗透脱水的动力学过程。分别使用Azuara模型和Fick第二扩散定律计算出了平衡时刻的失水率、固形物增加率以及相应的水分和固形物有效扩散系数。设计了均匀实验,通过曲面拟合的方法得到了水分、固形物有效扩散系数与因素的回归方程。结果表明:失水率随着葡萄糖溶液浓度增加而增大,但随着温度的升高而降低;固形物增加率随着溶液浓度和温度的增加而增加。Azuara模型可用来预测失水率和固形物增加率,通过曲面拟合得到的有效扩散系数回归方程拟合性较高。有效扩散系数反映了失水率和固形物增加率达到平衡时刻的快慢程度。     

植物甾醇对油脂中VA体外模拟控制性释放的影响

以植物甾醇为有机凝胶剂来制备人造奶油产品,研究体外模拟消化模型中不同质量分数(%)的植物甾醇(0%~7%)对VA释放速率的影响,并通过测定扩散系数及侵蚀常数来解释其动力学机制。试验结果显示,VA释放速率随植物甾醇质量百分数升高而降低,体外模拟消化2 h时甾醇质量分数7%的奶油中VA的释放率比空白组降低26%;Rritger-Peppas方程拟合结果表明当甾醇质量百分数为0%~5%时,VA扩散为非Fick扩散;VA浓度和甾醇质量百分数是扩散的主要驱动力,扩散系数随甾醇质量百分数的升高而减小;另外,侵蚀速率随甾醇质量百分数的升高而降低,当甾醇质量百分数为7%时,奶油侵蚀常数比空白组小3倍;随着储存时间延长,储存温度降低,侵蚀常数逐渐减小;当人造奶油中添加单双硬脂酸甘油酯时侵蚀常数约为分子蒸馏单甘脂的2倍。     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.