酶法制备蔗渣膳食纤维

利用蔗渣为原料,对蔗渣中膳食纤维的酶法制备工艺进行试验研究。通过单因素试验、正交试验和极差分析,得出最佳工艺条件。结果表明,在混合酶(α-淀粉酶与蛋白酶质量比为1∶3)用量0.3%、65℃处理90 min,脂肪酶用量0.4%、50℃处理60 min时,膳食纤维得率较高。该酶法工艺为蔗渣膳食纤维的制备提供参考。     

双酶法分离提取米糠膳食纤维的研究

米糠是稻谷加工的副产物之一,其中米糠膳食纤维含量高达35%~50%,是理想的膳食纤维来源。实验研究了双酶法分离提取米糠膳食纤维的最佳工艺条件,并对所提膳食纤维的基本成分进行了分析。根据正交实验结果表明,提取米糠膳食纤维时,除淀粉的最佳条件为:耐高温淀粉酶,酶解时间3.5 h,酶解温度75℃,酶用量20μL;除蛋白的最佳条件为:碱性蛋白酶,酶解时间2.5 h,酶解温度60℃,酶用量2%。在最优条件下分离提取得到的米糠膳食纤维:总膳食纤维、不溶性膳食纤维和可溶性膳食纤维纯度分别为87.26%、68.23%和3.99%。根据扫描电镜结果显示,不溶性和可溶性膳食纤维表面均具有明显的蜂窝状结构。     

化学法结合酶法提取牛蒡中的可溶性膳食纤维

本文以牛蒡为原料,先用化学方法处理得到牛蒡可溶性膳食纤维(SDF)和牛蒡渣,然后再用酶法处理前一步得到的牛蒡渣,进一步提取牛蒡可溶性膳食纤维。通过单因素试验及正交试验对化学法和酶法条件进行了优化。结果表明,化学法制备可溶性膳食纤维的较佳工艺条件是:温度100℃,反应时间20 min,pH10.0,物料比1∶15,在此条件下,牛蒡提取SDF得率为11.2%。使用复合多糖酶处理前一步得到的牛蒡渣,酶法提取可溶性膳食纤维的较佳条件为:复合多糖酶的用量8%、酶解温度40℃、酶解时间1h、pH 3.9、料液比为1∶18,在此条件下,SDF得率为4.82%。     

脱脂米糠制备膳食纤维工艺条件的优化

采用化学试剂—酶结合分离法,以脱脂米糠制备膳食纤维.分别考察α-淀粉酶用量、酶解时间、碱解浓度、碱解时间对膳食纤维提取率的影响,并采用四元二次回归通用旋转组合试验优化工艺参数.结果表明:在α-淀粉酶用量0.40％,酶解40min,碱解浓度4.00％,碱解时间45min的条件下,从脱脂米糠中提取膳食纤维的得率为39.30％.     

酶法制备紫红薯膳食纤维的工艺研究

为了确定酶法制备紫红薯膳食纤维的最优工艺参数,提高产品纯度,以膳食纤维的膨胀力为指标,采用单因素和正交优化试验对酶法制备紫红薯膳食纤维的工艺进行研究.结果表明,将紫红薯渣按1:10(质量比)用水调成浆,糊化后冷却至75℃,按干薯渣的0.5%加入混合酶[m(淀粉酶):m(糖化酶)=7:3],保温处理150min;灭酶后降温至60℃,按原料的0.2%加入木瓜蛋白酶处理60min.样品的酸性洗涤膳食纤维含量达75.46%.该法为紫红薯膳食纤维的制备提供试验依据.     

椰蓉膳食纤维的酶法提取与理化性质分析

探讨水解酶(α-淀粉酶、蛋白酶和糖化酶)的添加量和水解时间对椰蓉膳食纤维提取率的影响作用大小的基础上优化酶法提取椰蓉膳食纤维的工艺参数,进一步分类制备可溶性膳食纤维(Soluble Dietary Fiber,SDF)和不溶性膳食纤维(Insoluble Dietary Fiber,IDF),并研究其理化性质。结果表明,椰蓉膳食纤维的最佳酶法提取工艺为A_3B_2C_2D_2E_1F_2,即α-淀粉酶用量0.3%,酶解时间45 min,蛋白酶用量0.2%,酶解时间为45 min,糖化酶用量20μL/g,酶解时间为30 min,该条件下椰蓉膳食纤维的提取率高达为89.68%。制备所得的椰蓉IDF的溶胀性、持油力和持水力最高,分别达15.33 mL/g、6.51 g/g和12.71 g/g,可以作为一种潜在的功能性膳食纤维添加组分应用到食品工业中。     

挤压膨化辅助提取米糠可溶性膳食纤维及其特性研究

以新鲜米糠为原料,在单因素和正交试验基础上,通过分析不同挤压工艺和酶解条件对米糠中可溶性膳食纤维提取率的影响,优化挤压膨化辅助酶水解技术提取可溶性膳食纤维。同时采用扫描电子显微镜、差示扫描热量法等表征可溶性膳食纤维的结构及物化特性。试验结果表明,在挤压温度130℃、螺杆速度200 r/min、物料含水量20%,酶用量2.0%、酶解温度75℃、酶解时间90 min、p H 6.0的条件下,可溶性膳食纤维提取率为30.35%。米糠可溶性膳食纤维表面形态疏松,呈蜂窝颗粒状,内部由纤维素类物质形成支撑主体,热力学相对稳定。与未经挤压膨化处理提取的可溶性膳食纤维相比,挤压辅助提取的可溶性膳食纤维具有更高的持水力、结合水力、溶胀力、结合脂肪能力及丰富的空间网状结构,结构及物化特性均得到明显改善。     

响应面法优化超声辅助酶法提取米糠水溶性膳食纤维

以米糠为原料,采用超声辅助酶法提取米糠水溶性膳食纤维,探讨加酶量、超声时间、超声功率和料液比对得率的影响,以水溶性膳食纤维的得率为响应值,通过Box-Behnken实验设计进行超声辅助酶法提取米糠水溶性膳食纤维的工艺优化研究。结果表明:影响米糠水溶性膳食纤维得率的主次因素依次为加酶量、料液比、超声时间、超声功率,最佳提取工艺为酶终浓度5.3%、超声时间5min、超声功率415W、料液比1∶24(g/m L)。在此条件下,米糠水溶性膳食纤维得率最高,预测值为9.22%,验证实验得到的得率为9.36%。     

双酶法制备蓝莓果渣膳食纤维的工艺

以蓝莓加工过程中产生的副产品果渣为原料,膳食纤维的提取率为指标,通过单因素试验和正交试验,研究了双酶法制备膳食纤维的最佳工艺。试验结果表明,当α-淀粉酶添加量为0.3%,α-淀粉酶酶解温度为75℃,碱性蛋白酶添加量为0.3%,碱性蛋白酶酶解温度为45℃时,膳食纤维的提取率达到50.98%。     

响应面法优化米糠水溶性膳食纤维酶法提取工艺研究

对超声辅助混合酶法提取米糠水溶性膳食纤维(RSDF)的提取工艺进行了研究。考察了酶及其添加量、料液比、超声功率和超声时间等对RSDF得率的影响。经过单因素试验和central composite design中心复合响应面分析法,确定了RSDF的最佳提取工艺为:添加6%的木瓜蛋白酶,60℃水解1h并灭酶后,再添加1.5%木聚糖酶、料液比1∶25g/ml,55℃水浴超声(600 W)5min。在此条件下,米糠水溶性膳食纤维得率最高为25.10%。     

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