酶法结合高压法制备甘薯回生抗性淀粉

本试验以甘薯淀粉为原料,采用酶解-压热法制备RS3型抗性淀粉,研究了淀粉乳浓度、压热时间、压热温度、α-淀粉酶、预糊化时间、pH值以及冷藏时间和温度对抗性淀粉制备产率的影响。结果表明：甘薯回生抗性淀粉最佳制备条件为：甘薯淀粉乳浓度为10%;α-淀粉酶加量为120U/ml;预糊化时间为30min;最佳压热温度为120℃,压热处理时间为30min;老化温度为4℃,时间为12 h。采用此工艺制备甘薯回生抗性淀粉,其制备产率可达到7.365%。     

玉米抗性淀粉的制备及其物理特性的研究

试验以普通玉米淀粉为原料,系统研究了121℃压热条件下淀粉浓度、压热时间、冷却方式及老化方式、老化时间对抗性淀粉得率的影响,确定最佳的试验方案.结果表明:在压热温度为121℃的条件下,淀粉浓度30%,压热时间30 min,采用室温下自然冷却的方式,4℃回生12 h,抗性淀粉得率为10.31%.并采用X-衍射、紫外光谱法研究了抗性淀粉常见的物理特性.     

压热法制备荞麦抗性淀粉工艺优化

研究了压热法制备荞麦抗性淀粉的工艺参数。比较了不同淀粉乳浓度、热处理温度、热处理时间、淀粉乳pH值对荞麦抗性淀粉得率的影响。采用三因素二次回归旋转正交组合设计,优化荞麦抗性淀粉制备参数,建立了各因子与荞麦抗性淀粉得率关系的数学回归模型,确定了最佳的制备条件:淀粉乳浓度为59.41%,压热处理温度为123.33℃,压热时间60.79min,荞麦抗性淀粉的产率理论最高值可达16.6053%。     

碱性蛋白酶水解脱除蛋白的橡子淀粉分离工艺条件优化

为优化碱性蛋白酶水解蛋白的橡子淀粉提取工艺条件,选择酶解时间、温度、pH值、酶用量等因素进行单因素试验和正交试验,确定了适宜的橡子淀粉提取工艺条件。结果表明,碱性蛋白酶水解去除蛋白的pH值和酶解温度对橡子淀粉中总淀粉含量的影响较大,影响程度依次为pH值〉酶解温度〉酶解时间〉酶用量;碱性蛋白酶水解去除蛋白的适宜工艺条件为pH值为11、酶解温度为45℃、酶解时间为140 min、酶用量为600 U/g。结合1%双氧水漂白处理12 h后,橡子淀粉中的蛋白未检出。     

蕨根抗性淀粉的制备工艺研究

压热法制备蕨根抗性淀粉的过程中,淀粉乳质量分数、压热温度、pH、压热时间和老化时间对蕨根抗性淀粉质量分数有不同程度的影响.通过三因素二次正交旋转组合设计,得出淀粉乳质量分数、pH、压热时间对蕨根抗性淀粉质量分数的影响大小次序为:淀粉乳质量分数>pH>压热时间.压热法制备蕨根抗性淀粉的最佳工艺条件为:淀粉乳质量分数28.7%,pH7.8,121℃压热处理38 min,4℃老化24 h,得到的蕨根抗性淀粉质量分数为10.94%.     

纤维素酶-压热法制备马铃薯抗性淀粉工艺参数优化

为了提高抗性淀粉的得率,并获得抗性淀粉制备方法的最佳工艺参数,该试验以马铃薯淀粉为原料,抗性淀粉得率为评价指标,采用纤维素酶-压热法制备马铃薯抗性淀粉。研究淀粉乳浓度、酶添加量、酶解时间、压热温度、压热时间5个因素对马铃薯抗性淀粉得率的影响,在单因素试验的基础上,通过正交试验优化得出马铃薯抗性淀粉的最佳制备工艺条件,即淀粉乳含量25%、淀粉乳pH 5.0、酶用量30 U/mL、酶解时间50 min、压热温度125 ℃、压热时间30 min、老化温度4 ℃、老化时间18 h,在此条件下抗性淀粉的得率为30.33%。     

压热法制备甘薯抗性淀粉的工艺优化

利用压热法结合响应面分析法,优化甘薯抗性淀粉的制备工艺。以甘薯全粉为原料,研究全粉乳质量分数、pH、压热温度、压热时间、冷藏时间对甘薯抗性淀粉得率的影响。结果表明,响应面分析法得到甘薯抗性淀粉的最佳制备工艺条件为:全粉乳质量分数25.50%、pH7.30、压热温度120 ℃、压热时间31.20 min、冷藏时间24 h。在此条件下,甘薯抗性淀粉的得率为9.41%,与理论值较为接近,响应面模型与实际情况拟合良好,为获得甘薯抗性淀粉的工业化生产提供了参考。     

酶解-压热法制备淮山药抗性淀粉

以淮山药淀粉为原料,通过正交试验研究酶解-压热法制备抗性淀粉的最佳工艺参教.在压热法的最佳工艺基础上,通过使用普鲁蓝酶处理淀粉,使产率大大提高,该法所得的产率最高可达16.47%左右.确定压热处理最佳工艺条件为淀粉乳浓度25%,pH值8.0,121℃压热处理40 min,冷藏老化时间为36 h.确定制备抗性淀粉的最佳酶作用参数为加酶量4 U/g干淀粉,作用温度55℃,作用时间8 h.     

以机械活化玉米淀粉为原料酶法制备低DE值麦芽糊精

以机械活化玉米淀粉为原料制备低DE（Dextrose Equivalent）值麦芽糊精,通过单因素实验研究了机械活化时间、反应时间、反应温度、酶添加量、底物浓度、pH对产品DE值的影响,并在此基础上进行了正交实验。结果表明,经机械活化预处理后的淀粉酶解反应活性明显提高,酶解速度加快,酶解时间大大缩短,而原淀粉在相同条件下几乎不与酶作用。正交实验确定了制备工艺的最佳条件为：酶添加量3u·g-1淀粉干基,pH6.5,水解温度45℃,底物浓度10%,水解时间4min,按此条件所得的麦芽糊精DE值为2.35%。并用红外光谱和X-射线衍射对麦芽糊精进行了分析。     

双酶法水解橡子淀粉工艺研究

为掌握中温α-淀粉酶和糖化酶联合水解橡子淀粉的工艺条件,该研究在单因素试验的基础上,运用正交试验设计方法对橡子中的淀粉水解工艺进行了研究和优化。结果表明,橡子淀粉最佳液化工艺条件为中温α-淀粉酶添加量30 U/g,液化温度70 ℃,CaCl2添加量0.3%,液化pH 7.5,液化时间120 min,葡萄糖当量（DE）值为27.79%;最佳糖化工艺条件为糖化酶添加量300 U/g,糖化温度50 ℃,糖化pH 4.5,糖化时间120 min,DE值为48.13%。     

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