响应面优化瓜蒌中葫芦素提取工艺及其抑菌作用

试验以瓜蒌为原料,利用超声波法提取瓜篓中葫芦素,在此基础上利用葫芦素进行抑菌试验。试验确定了提取瓜篓中葫芦素得率的最佳条件组合:甲醇体积分数70%,超声时间20 min,料液比1︰10 g/mL,超声功率90 W。在此条件下葫芦素的得率为1.846%。通过葫芦素对大肠杆菌和金黄色葡萄球菌的抑菌试验研究,确定了葫芦素对大肠杆菌和金黄色葡萄球菌均具有一定的抑制作用。     

不同方法提取甜荞麦麸皮总黄酮研究

为提高荞麦麸皮利用率,采用乙醇浸提法、超声波辅助提取法和微波加热提取法对提取甜荞麦麸皮黄酮类化合物工艺进行研究。实验结果表明,乙醇浸提法最佳工艺条件为:用50倍50%乙醇在70℃水浴中浸提2.5 h,浸提三次,总黄酮得率为2.4195%;超声波辅助提取法最佳工艺条件为:用60倍70%乙醇在70℃下超声波30 min,超声波提取三次,总黄酮得率为2.8953%;微波加热提取法最佳工艺条件为:用40倍50%乙醇在360 W功率下加热90 s,提取两次,总黄酮得率为2.7963%。比较三种方法结果,以超声波辅助提取法较优,更适于工业化生产。     

不同方法提取甜玉米芯多酚对比研究

以美国脆王甜玉米芯为原料,分别采用乙醇浸提、超声波辅助和微波辅助提取甜玉米芯多酚并选择最优方法通过单因素试验及L_9(3~4)正交试验设计,确定甜玉米芯多酚最佳提取条件。结果表明:超声波辅助提取法效果明显优于乙醇浸提法和微波辅助提取法,甜玉米芯多酚提取率为95.10%。单因素试验及正交设计表明当甜玉米芯多酚提取3次,提取温度40℃,超声时间为60min,超声功率300W,乙醇浓度70%,料液比1:25(g/mL)时,多酚提取率达到最高,为96.04%,多酚得率为16.24 mg/g。本试验为甜玉米芯多酚分离纯化的进一步研究提供试验依据。     

超声波辅助提取杜仲翅果桃叶珊瑚甙工艺优化

目的：研究超声波辅助提取杜仲翅果中桃叶珊瑚甙的较佳工艺条件,为杜仲翅果资源的综合开发利用提供参考。方法：在单因素试验的基础上,通过Box-Behnken试验设计确定乙醇体积分数、超声波功率、提取时间及液料比等因素的最佳工艺条件。结果：超声波辅助提取杜仲翅果中桃叶珊瑚甙的最佳提取工艺条件为乙醇体积分数72.1%、超声波功率300W,提取时间20.5min、液料比12.3:1(mL/g),在该条件下杜仲翅果桃叶珊瑚甙的实际提取率为5.91%。在试验范围内各因素对桃叶珊瑚甙得率影响大小依次为乙醇体积分数＞料液比＞提取时间。结论：超声波辅助提取法能够较好地提取杜仲翅果桃叶珊瑚甙。     

超声波法辅助提取金针菇菌根核苷酸的工艺优化

试验探讨了超声波辅助提取金针菇菌根核苷酸的最佳工艺条件。以核苷酸得率为指标,经过超声波辅助提取制得核苷酸提取液。通过单因素试验和响应面试验优化核苷酸的提取工艺条件。结果表明:超声波法提取金针菇菌根核苷酸的最优条件是液固比30:1、超声时间53 min、超声温度57℃和氢氧化钠浓度1.44%,在此工艺下核苷酸得率为1.47%。     

超声波辅助酶法提取银杏叶总内酯的工艺研究

目的:优化超声波辅助酶法提取银杏叶总内酯的工艺条件。方法:以银杏叶总内酯提取率为试验指标,通过单因素试验和正交试验,确定其最佳工艺条件。结果:超声波辅助酶法提取银杏叶总内酯的最佳工艺条件为:半纤维素酶的质量浓度为0.7%、酶解温度为50℃、酶解时间为90 min、超声功率为420 W、超声时间为10 min,在此条件下,银杏叶中总内酯提取率达到0.5354%。结论:超声波辅助酶法提取银杏叶总内酯的工艺简单,提取率高,可用于银杏叶总内酯的工业化生产。     

超声波辅助酶法提取洋葱多糖的工艺研究

为探究超声波辅助酶法提取洋葱多糖的最优工艺,试验在单因素试验的基础上,采用Box-Behnken中心组合设计响应面试验对超声波辅助酶法提取洋葱多糖的工艺进行优化,得到超声波辅助酶法提取洋葱多糖的最佳工艺条件:料液比为1︰30(g/m L),纤维素酶添加量0.3%,提取温度为50℃,提取p H 5.0,超声功率200 W,超声时间为30 min,在此提取条件下洋葱多糖的提取率可以达到11%左右。     

超声波辅助提取蚕蛹多糖工艺的优化

以脱脂蚕蛹粉为原料,通过超声波辅助提取,对蚕蛹多糖的提取工艺进行优化。以超声波提取时间、料液比、超声波功率为影响因素,考察对蚕蛹多糖的提取率的影响。在单因素试验基础上,利用Box-Behenken试验设计原理采用三因素三水平的响应面分析法对超声波辅助提取蚕蛹多糖的工艺条件进一步优化。试验结果表明,超声波辅助提取脱脂蚕蛹多糖的最佳工艺条件为:料液比1∶30(g/m L),功率550 W,提取时间65 min。在此条件下,提取蚕蛹多糖率达到94.36%。     

超声波辅助提取花生壳总黄酮工艺的优化

目的：确定超声波辅助提取花生壳总黄酮的工艺条件。方法：以花生壳总黄酮提取率为指标,以乙醇浓度、料液比、提取时间、提取温度为因素进行试验设计,对超声波辅助提取花生壳总黄酮的工艺进行优化研究。结果：超声波辅助提取花生壳总黄酮的最佳工艺条件是超声功率120W、频率40Kz条件下,乙醇浓度70%、料液比1：30、提取温度55℃、提取时间40min,此条件下花育16品种成熟花生壳的总黄酮提取率为1.98%,远高于目前相关文献报道的花生壳总黄酮提取率。结论：本试验结果可作为超声波辅助提取花生壳总黄酮工艺制定的依据。     

超声波辅助提取浒苔多糖的工艺研究

目的：优选超声波法辅助提取浒苔多糖的工艺条件。方法：在单因素试验的基础上,采用正交设计,对超声波辅助提取浒苔多糖的工艺条件进行优选。结果：优选的浒苔多糖超声波辅助提取工艺条件为超声波功率800W、超声处理时间45min、料液比1∶30,浒苔多糖的提取率为27.99%;超声处理的三因素中,处理时间影响最大（P〈0.01）,其次是超声波功率（P〈0.05）;超声波辅助提取法比单纯热水浸提法,浒苔多糖得率提高了2倍,提取时间缩短了60%。结论：超声波法辅助提取浒苔多糖具有操作简便、多糖提取率高、提取时间短的优点,在浒苔多糖产业化生产中有应用前景。     

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.     

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.     

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.