动物色素-龙虾壳红色素的超声强化提取工艺优化

研究了以龙虾壳为原料,用95%食用乙醇作溶剂,在超声场的介入下对龙虾壳红色素提取率的影响。试验结果表明:超声场的介入有利于龙虾壳红色素的提取;并通过均匀试验设计确定了最佳提取工艺条件:超声功率90%、超声时间75min、超声温度50℃,在此条件下龙虾壳红色素的提取率可达85%。对比试验结果显示:超声场介入的最佳提取工艺比传统提取工艺提高35%。     

槟榔红色素的提取工艺优化及稳定性研究

为探讨槟榔中红色素物质的性质,采用溶剂浸提的方法,对槟榔红色素的提取条件进行研究。结果表明：槟榔红色素采用体积分数70% 乙醇溶液提取效果较好,最佳提取工艺为料液比1:40(g/mL)、温度80℃、提取时间4h、pH7.0,该条件下槟榔红色素的提取率为9.82%。该色素在光照及酸性条件下,稳定性较好;碱性条件以及柠檬酸、葡萄糖、苯甲酸钠、山梨酸钾、碳酸氢钠等食品添加剂对其有增色作用。该色素的耐还原能力较好而抗氧化能力较差,当H2O2 体积分数为4.0% 时,其损失率达13.41%。金属离子Na+、K+、Ca2+、Mg2+ 对色素的影响不大,而Fe3+、Cu2+、Zn2+ 对红色素有明显的破坏作用。通过红色素提取物的特征颜色反应,初步判断该色素含有花色苷及黄酮类化合物。     

鸡血藤红色素提取工艺研究

研究鸡血藤红色素溶剂提取法的最佳提取工艺。以提取液在460nm波长处的吸光值为考察指标,在单因素实验基础上,进行正交实验,考察提取温度、提取时间、液料比、溶剂pH对色素提取效果的影响。结果表明:液料比是影响色素提取效果的主要因素;溶剂浸提法的最佳提取条件为提取温度60℃、时间120min、液料比30∶1、pH2的60%乙醇溶液,最佳提取次数为3次。在此工艺条件下,鸡血藤红色素提取率为96.7%。该提取工艺稳定,可用于鸡血藤红色素的提取。     

茗荷中食用红色素提取及稳定性研究

采用单因素分析和正交试验L16(45),确定了提取茗荷红色素的最佳工艺条件,并分析了茗荷红色素的稳定性.结果表明,最佳工艺条件为:料液比为1∶20,提取温度为50℃,提取剂的pH值为1,提取时间为120min.茗荷红色素的耐热性好,耐光性较差,在酸性条件、氧化剂和蔗糖、VC、淀粉和柠檬酸中稳定性较好;在还原剂、苯甲酸钠和山梨酸钾中稳定性较差;色素对金属离子的稳定性较高,Fe3 、Al3 、Ca2 对色素有增色效果,Cu2 使色素溶液变色,Mg2 、Na 和K 对色素无不良影响.     

油葵籽壳红色素酸化乙醇法提取工艺及其稳定性的研究

对油葵籽壳红色素的提取条件以及温度、pH、光照、常用食品添加剂、金属离子对油葵籽壳红色素稳定性的影响进行了系统研究。结果表明,料液比1:20(g/mL)、50℃恒温、30%乙醇(pH2.0)、浸提60min,采用三次浸提,提取得率可达96.76%。色素在pH值2～6,温度65℃以内比较稳定;光照能加快色素降解;K+和Ca2+对该色素无不良影响;而Cu2+、Al3+、Fe3+、Sn2+和Ph2+对该色素有较大影响;常用食品添加剂对色素稳定性无影响。因此,油葵籽壳红色素作为食用色素具有很好的开发价值。     

葵花壳红色素提取方法

通过对葵花壳红色素的提取、纯化方法以及稳定性实验研究,证实提取葵花壳红色素的可行性及其利用价值。以葵花壳为原料,采用超声波辅助溶剂法,即50%乙醇溶液(pH1～2)提取红色素,通过正交试验得最佳提取条件为超声温度55℃、料液比1:16(g/mL)、超声时间10min,经验证实验得葵花壳红色素的提取率为8.2%。葵花壳红色素的稳定性实验表明：加入不同浓度的氧化剂、还原剂、食品添加剂及不同环境光照处理,红色素的颜色、OD值变化较小,稳定性较好;但温度大于80℃及pH≥3条件下,红色素颜色和OD值变化较大,稳定性不好。将提取的粗品进行纯化试验,所得葵花壳红色素的提纯率为6.30%。     

醇溶法提取紫荆花色素及其稳定性研究

用95%的乙醇溶剂浸提法从紫荆花中提取红色素的最佳工艺条件为:提取时间0.8h,提取最佳pH为2,提取温度为85℃.通过减压蒸馏,所得紫荆花红色素产率为10.08%,乙醇回收率为78%.此红色素在520nm时的吸光值最大,NaC1对紫荆花红色素有增色作用,蔗糖对色素几乎无影响,H2O2溶液和金属离子对紫荆花色素有破坏作用,特别是Fe3+,Cu2+的加入使紫荆花红色素色泽出现异常.通过红外谱图对照分析,可知紫荆花红色素与玫瑰花色素同属于花色甙类化合物.     

花生衣红色素的提取及其稳定性研究

通过L9(34)正交试验确定花生衣红色素的最佳提取工艺,同时对其稳定性进行研究.结果表明:色素最佳提取工艺条件为:提取刺50%乙醇,浸提温度40℃,浸提时间80min,料液比1:25(g/mL).花生衣红色素的特征吸收峰为495 nm;该色素对pH、温度、光照、以及Vc、K+、Na+、Ca2+、Mg2+、Cu2+、Na2SO3稳定性较好,对柠檬酸、H2O2、Fe3+稳定性较差.     

紫甘薯天然红色素的提取及其稳定性研究

以紫甘薯为原料,分别研究了其天然红色素的提取方法、工艺以及该色素在不同环境条件下的稳定性。结果表明,紫甘薯天然红色素的最佳提取条件为:0.8%的柠檬酸溶液作提取剂、料液比为1:50、温度60℃、时间4h;提取后的天然紫甘薯红色素在酸性条件下较稳定,有着较好的耐热性和光稳定性,随着pH升高,稳定性下降;对抗坏血酸较敏感,使用时应尽量在低酸性环境下及避免高温和长时间的受热。     

辣椒中红色素的提取工艺研究

辣椒红色素是一种优质的天然红色素,在医药、食品、轻工业等行业具有广泛的应用价值。本文以干辣椒作为原料,研究了在色素提取过程中,采用碱液脱除辣素的方法以及在色素提取中对不同有机溶剂、不同提取条件和不同提取方法进行比较,探讨了影响色素得率和脱除辣素的工艺条件。通过感官鉴定的方法确定了除辣的最佳条件:用15%NaOH溶液在90℃下浸泡1.5h可基本上脱除辣椒粉中的辣素。确定了用乙酸乙酯浸提,超声法精提干红辣椒的最佳条件。第一步浸提:每次提取时间为3h,提取温度为30℃,提取辣椒所用的溶剂量为25ml/g,提取次数3次。第二步超声法:液固比(V/m)为12:1,超声时间为1h。色素的除辣效果明显,红色素的得率为:3.67%。     

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.     

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.     

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.     

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.