芦笋老茎中提取芦丁的研究

以芦笋老茎为原料,采用超声波辅助提取和乙醇浸提两种方法,研究提取温度、超声功率、乙醇体积分数和料液比对芦丁提取的影响,通过单因素试验与正交试验优化芦丁提取工艺条件。结果表明:超声波辅助法对芦笋老茎中芦丁得率明显高于乙醇浸提法,超声功率90 W,乙醇体积分数60%,提取温度80℃,料液比1∶25(m∶V)为最佳提取工艺。该条件下芦丁得率为4.53%。     

响应面法优化超声提取芦笋总皂苷

利用响应面法对超声提取芦笋总皂苷的工艺进行优化。实验研究了超声条件下影响芦笋总皂苷得率的因素,包括乙醇浓度、料液比、超声时间、超声温度,并通过响应面法优化提取工艺。根据中心组合设计原理采用三因素三水平的响应面分析法,得出了超声提取芦笋总皂苷的最佳工艺条件为:料液比1∶15(W/V),乙醇浓度74%,超声时间54min,超声温度50℃,此时芦笋总皂苷得率为13.06%,接近于模型预测值13.18%。     

‘赤霞珠’葡萄皮渣中原花青素的提取工艺研究

研究乙醇浸提法和微波辅助浸提法提取“赤霞珠”葡萄皮渣原花青素的工艺。乙醇浸提法研究提取时间、提取温度、料液比、乙醇浓度四个因素对原花青素提取率的影响;微波辅助浸提法研究微波时间、乙醇浓度、料液比三个因素对原花青素提取率的影响。乙醇浸提法的最佳提取工艺为：提取时间55min,提取温度50℃,料液比1:8.5(g/ml),乙醇浓度55%,提取率为2.61%;微波辅助浸提法的最佳提取工艺为：微波功率320W,微波时间30s,乙醇浓度50%,料液比1:13(g/ml),50℃恒温水浴中浸提30min,提取率为3.99%。在最佳提取工艺条件下研究pH 值对原花青素提取率的影响。乙醇浸提法和微波辅助浸提法分别在pH4.5 和pH5 时,原花青素提取率最大,提取率分别为2.67% 和4.11%,表明酸提高了原花青素的提取率。     

芦笋老茎总皂甙提取工艺优化

以芦笋老茎为原料,研究提取温度、提取时间、乙醇浓度、料液比对芦笋皂甙提取的影响.通过Taguchi稳健试验设计,确定最佳提取工艺条件为:提取温度75℃,提取时间2.5 h,乙醇体积浓度90%,料液比1:15(W:V),提取次数为2次.     

芦笋总皂苷的提取纯化及抗氧化研究

以芦笋总皂苷的提取率为考察指标,香草醛-冰醋酸法测定芦笋总皂苷的含量,采用正交设计法,对乙醇浓度、提取温度、提取时间、料液比4个因素进行考察,优化芦笋总皂苷提取工艺参数。芦笋总皂苷的最优工艺为:乙醇浓度为90%,提取温度为80℃,料液比为1∶40(g/mL),提取时间为1 h。在此条件下芦笋总皂苷提取率为10.68%。利用HPD-100大孔树脂对芦笋总皂苷提取液进行纯化,分别使用水、20%、50%、80%、95%的乙醇进行梯度洗脱。结果表明在乙醇浓度为50%的第3个流分时,总皂苷含量最高为51.0%。抗氧化试验表明,芦笋总皂苷纯化前后清除DPPH自由基的IC_(50)分别为147.43、140.05μg/mL;清除ABTS+自由基的IC_(50)分别为212.76、169.70μg/mL。     

五味子红色素超声波辅助提取工艺优化

目的:通过单因素和正交试验研究五味子红色素最优提取工艺。方法:采用超声波辅助提取法,以红色素提取率为指标,测定红色素的吸光度。pH为3的乙醇为提取溶剂,在单因素试验基础上,以乙醇浓度、料液比、超声时间、超声温度因素进行正交试验。结果:影响五味子红色素提取率的主要因素为料液比,其次为乙醇浓度和超声时间,最后为超声温度。最佳提取工艺为:pH 3的75%乙醇,料液比1∶50g/mL,超声时间30min,超声温度40℃。对比两种提取方法,超声波辅助提取法比浸提法所用温度低,且缩短了提取时间,提高了色素提取率。结论:该方法提取率高,简单易行,最佳工艺条件下提取率可达到1.5520%。     

番茄植株总黄酮提取工艺优化

以番茄植株为植物材料,研究乙醇浸提法提取其总黄酮的最佳工艺条件。以番茄植株总黄酮的提取量为考察指标,通过单因素试验和正交试验研究乙醇浓度、浸提时间、料液比和浸提温度对番茄植株总黄酮提取量的影响程度及最佳提取工艺条件。结果表明,上述四因素对番茄植株总黄酮提取量影响的大小顺序依次为乙醇浓度浸提温度料液比浸提时间;最佳提取工艺条件为:60%乙醇,料液比30 m L/g,70℃条件下,浸提1.5 h;最高提取量为0.408 mg/g。     

超声提取云南甜荞籽粒总黄酮工艺研究

以云南甜荞籽粒为研究对象,采用超声辅助醇提法提取荞麦总黄酮,并对工艺条件进行优化,为云南荞麦黄酮功能性成分的工业化提取提供科学依据。通过单因素试验,以总黄酮得率为考察指标,分别考察超声时间、温度、功率、乙醇浓度、料液比对荞麦总黄酮的影响,确定各因素的适宜水平。在此基础上,通过正交试验,确定云南甜荞籽粒中总黄酮提取的最佳工艺条件。结果表明:超声辅助醇提法对云南甜荞籽粒总黄酮具有良好的提取效果;超声提取甜荞籽粒总黄酮的最佳工艺条件为乙醇浓度80%、超声温度70℃、料液比1∶50(g/mL)、超声时间30min、超声功率150W;各因素的影响主次为乙醇浓度>料液比>超声温度。该条件下,荞麦总黄酮的得率为0.562%,是不经超声处理的乙醇浸提法的1.45倍。     

纤维素酶-乙醇结合法提取人参总皂苷提取工艺的研究

利用纤维素酶-乙醇结合法提取人参总皂苷。通过单因素试验考察提取体系pH、纤维素酶添加量、乙醇浓度、酶解温度、料液比、提取时间和提取次数对人参总皂苷提取率的影响。利用正交试验设计得到最优提取条件:提取温度为50℃、提取次数为2次,pH为5.0、乙醇浓度为40%,酶添加量为1.5%、固液比为1∶12、提取时间为2h。在最优条件下,纤维素酶-乙醇结合法提取人参总皂苷的得率为2.73%。对比试验证明,纤维素酶-乙醇结合法提取的人参总皂苷提取率高于参考条件下回流提取法和浸提法。结果证明纤维素酶-乙醇结合法可以得到较高的人参总皂苷提取率。     

川楝果实中川楝素不同提取方法的研究

为了获得川楝素最佳提取方法,以川楝果实为材料,采用高效液相色谱法检测,通过正交实验,分别研究溶剂浸提法、索氏提取法和超声波法提取川楝素的最佳提取条件。结果表明:溶剂浸提法的最佳提取工艺条件为:乙醇浓度70%,液料比8:1(mL/g),提取时间20min,提取次数3次,川楝素得率0.482%;索氏提取法提取川楝素的最佳工艺条件为:乙醇浓度70%,液料比15:1,提取时间4h,川楝素得率0.599%;超声波法提取川楝素的最佳工艺条件为:乙醇浓度80%,液料比12:1(mL/g),提取时间35min,超声功率450W,川楝素得率0.580%。三种提取方法进行比较,索氏提取法川楝素得率最高,为川楝素的最佳提取方法。     

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.