超声波处理对苦荞麦萌发、芽苗还原糖和总黄酮含量及抗氧化活性的影响

采用超声波预处理苦荞麦种子,研究超声波的功率、时间和温度对苦荞麦种子萌发率及麦苗还原糖、总黄酮含量和对DPPH自由基清除能力的影响。结果表明:超声波的功率、时间和温度对种子的初始萌发率影响显著。在超声波功率280 W、温度20℃、时间35min处理条件下,苦荞麦种子的初始萌发率和最终萌发率分别达88.00%和100%。在超声波功率240 W、温度15℃、时间35min处理条件下,苦荞麦芽苗(4d)中还原糖含量最高达11.24g/100g,分别比种子和对照增加303.99%和40.03%。而在超声波功率280 W、温度30℃、时间30min处理条件下,苦荞麦芽苗(6d)中总黄酮的含量达9.46 g/100 g,分别比种子和对照增加228.07%和69.71%,该条件下芽苗对DPPH自由基的清除率达86.47%。     

超声波辅助提取蜈蚣藻多糖的工艺优化研究

对蜈蚣藻中可溶性粗多糖的提取工艺进行研究。采用单因素试验和L9(33)正交试验研究温度、超声处理时间、提取次数和超声波功率对多糖提取率的影响。结果表明,超声波功率是影响蜈蚣藻多糖提取的主要因素,其次是提取时间,再次是提取温度;最佳工艺为超声波提取温度70℃、超声处理时间15min、超声波功率为450W、提取3次;多糖提取率为62.75%,总糖含量为81%。     

超声波协同纤维素酶提取山药多糖的工艺及组分测定研究

选用食用山药为原料,采用超声波协同纤维素酶酶解法分别研究了超声波功率、提取温度、提取时间、酶量对多糖提取量的影响;并且通过正交试验得出山药多糖提取最佳工艺。结果表明：各因素对山药多糖提取量影响的主次顺序为：时间、功率、温度,其最佳提取参数是：在固液比为1g：15ml,酶量为2%,pH为4.72的条件下：提取温度为50℃,提取时间为100min,功率为：450W。在此工艺条件下,多糖提取量为24.8mg/g。所得多糖通过薄层层析法,可知其由木糖、葡糖糖、半乳糖所组成。     

超声波辅助法提取米糠多糖的工艺研究

研究超声波辅助提取米糠多糖中温度、时间、加水量、超声功率对多糖提取率的影响,通过单因素实验和正交实验发现,温度对多糖提取率的影响最大,功率对多糖提取结果的影响最小,超声波辅助提取米糠多糖的最佳工艺条件为:温度80℃、时间70min、加水量20倍、功率200W,此时米糠多糖的提取率为1.75%,比热水法的提高了66.98%。     

柑橘皮渣超声波辅助酶解工艺的建立及其优化

以柑橘皮渣为原料,首先通过单因素实验研究果胶酶、纤维素酶和淀粉酶等混合酶添加量和配比、酶解时间、温度和pH值以及超声波功率等因素对皮渣中碳源酶解效率的影响。以此为基础,采用响应曲面法中Box-Behnken设计研究不同酶解参数组合(混合酶量—超声波功率—酶解温度—酶解时间组合)对柑橘皮渣酶解后还原糖含量的影响并建立四元二次方程模型以进行参数优化。结果显示,当混合酶量为0.54 mg/g、超声波功率为385 W、酶解温度和时间分别为49.2℃和4.3 h时,柑橘皮渣酶解滤液中还原糖含量最高为58.91 g/L,模型回归系数高(R~2=0.9213)且预测精确(相对误差为2.23%)。因此,此优化结果可为利用柑橘皮渣开发高效发酵型碳源提供数据支撑。     

超声波法提取苦竹叶多糖的工艺研究

以苦竹叶多糖的含量为指标,对超声波功率、溶剂量、提取时间三个影响超声波法提取苦竹叶多糖含量的因素进行考察。结果表明,在三个因素中溶剂量对提取含量的影响最大,超声波功率次之,提取时间对结果的影响最小。超声波功率、溶剂量和提取时间对苦竹叶多糖提取的影响均具有显著性意义（P〈0.05）。超声波法提取苦竹叶多糖的最佳工艺条件为：超声波功率50W,35倍量水,提取30min;提取含量为14.084mg·g-1。     

超声波辅助复合酶法提取芦荟多糖的研究

利用超声波辅助复合酶法提取芦荟多糖,并对比有无超声波辅助下复合酶法提取所得芦荟多糖的提取率。选取超声波功率、提取时间、提取温度、复合酶添加量进行单因素和正交试验,以芦荟多糖的提取率为指标进行优化。确定芦荟多糖的最佳提取工艺为：超声波功率100W,提取时间50min,提取温度50℃,复合酶添加量为2%（纤维素酶与果胶酶配比为3∶1）。此条件下,芦荟多糖的提取率为8.42%,较单纯的复合酶法提取率提高41.3%,且提取的芦荟多糖具有较强的抗氧化能力。     

响应面法优化超声波协同酶法提取杜仲叶多糖工艺

为提高杜仲叶多糖的提取效率,研究杜仲叶多糖的超声波协同酶法提取工艺。以多糖得率为指标,首先考察复合酶添加量、pH、提取温度、超声波功率、液料比和提取时间等因素对多糖得率的影响,再通过Plackett-Burman设计筛选出影响显著因素,并对显著因素进行最陡爬坡实验,最后采用Box-Behnken实验优化提取工艺。结果表明,复合酶添加量、pH与超声波功率为影响显著因素(P<0.05),其重要性依次为pH > 超声波功率 > 复合酶添加量。最佳提取工艺参数为:复合酶添加量3.7%、pH4.0、超声波功率100 W、提取温度45 ℃、液料比20:1 mL/g和提取时间15 min。在此条件下多糖得率实验值为4.79%±0.02%,与理论值4.87%接近。研究结果说明,与传统提取工艺相比,超声波协同酶法提取工艺能快速高效地提取杜仲叶多糖,大大降低提取成本,对杜仲叶多糖的工业化生产具有重要意义。     

响应面法优化笋头多糖微波-超声波辅助提取工艺

本文以福建毛竹笋笋头为原材料,在单因素实验的基础上,结合响应面分析法对微波-超声波联合辅助传统水提笋头多糖的工艺参数进行优化。结果表明,微波-超声波联合辅助传统水提笋头多糖的最优工艺参数为料液比1:30 g/mL、水浴温度95℃、水浴时间2.0 h、超声波功率600 W、微波功率300 W、微波-超声波时间3.0 min。在此条件下笋头多糖得率为10.05%,对比传统热水浸提法笋头多糖得率提高了32.06%。经检测,笋头多糖的总糖、蛋白质和糖醛酸含量分别为74.87%、4.05%和1.89%。该方法能显著提高笋头多糖得率,可为竹笋的综合利用和笋多糖产品的进一步开发提供一定参考。     

山茱萸籽粕亚临界水降解动力学及多糖性质研究

本实验以山茱萸籽粕为原料,进行山茱萸籽粕亚临界水降解研究,测定不同降解温度、降解时间下液态产物的还原糖含量,采用Saeman模型模拟分析,建立降解动力学方程,得到降解动力学参数,并对降解物进行理化性质的分析。结果表明,Saeman模型能较好反映山茱萸籽粕亚临界水降解的过程,初步降解的反应活化能E_a1为29.47 kJ/mol、还原糖降解活化能E_a2为22.21 kJ/mol、指前因子K₁₀为101.49 min-1、K₂₀为20.28 min-1,在降解温度160 ℃、降解时间20 min条件下,能得到产量较高的还原糖。单糖组成分析表明,山茱萸籽多糖主要由葡萄糖、木糖、半乳糖、半乳糖醛酸组成,其总糖含量高达78.82%;扫描电镜和红外光谱结构分析结果表明,多糖结构呈表面光滑,无规则颗粒状,粒径大小不一的球状结构物,为吡喃型糖苷环骨架;抗氧化活性分析结果表明,山茱萸籽多糖具有较好的自由基清除能力,在质量浓度为1.0 mg/mL时,对DPPH自由基、羟自由基和ABTS自由基清除率分别为85.61%、63.40%、76.20%。本试验结果为山茱萸籽多糖的进一步分离纯化和理化特性、形态结构的分析提供了参考。     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press