硬脂酸酶解淀粉的吸附性能研究

目的 研究酶解酯化改性后玉米淀粉的吸附性能。方法 以玉米淀粉为原料, 超声乳化后用脱支酶酶解淀粉, 再用硬脂酸进行疏水改性得硬脂酸酶解淀粉。利用红外、X射线衍射对酶解淀粉及硬脂酸酶解淀粉进行结构表征, 并对其吸油性、吸附性进行测试。结果 酶解后淀粉的化学结构及结晶结构没有变化, 只是结晶比例增加, 硬脂酸酶解淀粉的衍射峰强度和位置发生变化; 与玉米原淀粉相比, 酶解淀粉及硬脂酸酶解淀粉的吸油率及对亚甲基蓝的吸附性提高, 且随着硬脂酸用量的增加, 硬脂酸酶解淀粉的吸油率增大; 当硬脂酸用量为5%时, 对亚甲基蓝的吸附率最高。结论 酶解和硬脂酸酯化处理可有效提高淀粉的吸附性能。     

制备交联疏水化双改性淀粉工艺参数的优化研究

为提高淀粉材料的力学性能和耐水性能,以六偏磷酸钠为交联剂,有机硅烷偶联剂KH-570为疏水化改性剂,通过正交试验和四因素二次旋转正交组合试验设计,对玉米淀粉交联疏水化双改性工艺参数进行优化。结果表明：淀粉交联改性的最佳工艺参数为pH值11,六偏磷酸钠的用量1．5％,温度40℃,时间2h;淀粉疏水偶联化改性最佳工艺参数为乙醇浓度95．70％,KH-570用量1．68％（占淀粉干基）,稀释度2．81％,反应时间29．61min。改性淀粉吸水率最小为16．23％。     

基于疏水改性淀粉的亲水性修饰及其乳化性研究

用环氧丙烷作为醚化剂对玉米淀粉进行醚化处理后,再采用硬脂酸作为酯化剂进行酯化反应,使淀粉分子上面同时接入亲水性的羟丙基和疏水性的烷基,避免单纯酯化改性只接入疏水性基团,导致亲水性降低,从而导致在水包油体系中淀粉的乳化性差的缺陷。本文对制备疏水性玉米淀粉的醚化亲水性修饰工艺进行了研究,结果表明:反应体系的醚化温度为40℃,醚化pH值为12,醚化反应时间为14小时,环氧丙烷的添加量为淀粉干基重量的8.5%时,经过亲水性修饰的硬脂酸淀粉酯的凝沉稳定性最高,经过在此条件下进行验证试验制备的该产品的乳化性达到73%,乳化稳定性达到70%,比未经过修饰的硬脂酸淀粉酯的乳化性能显著提高。该工艺是一种有效提高疏水性淀粉乳化性能的新技术,具有重要的推广应用意义。     

高压均质制备玉米淀粉-脂质复合物及其性质研究

研究一种利用高压均质技术制备玉米淀粉-脂质复合物的工艺,并对其热特性质进行研究。以玉米淀粉和脂肪酸为原料,对工艺中脂肪酸种类及添加量、高压均质压力、高压均质次数和糊化预处理温度等因素进行单因素试验,在此基础上进行正交优化。试验确定脂肪酸种类为硬脂酸,得到最佳制备工艺条件为:硬脂酸添加量0.5%,高压均质压力100 MPa,高压均质次数3次,糊化预处理温度95℃。玉米淀粉-脂质复合物的复合指数达72%。     

“HC—3”对不同纸浆的增强作用

一、前言“HC—3”草木浆专用增强剂是由杭州化工研究所磐安造纸淀粉工业公司生产的最新型造纸用助剂。“HC—3”是玉米淀粉的改性产品，由于其分子链上引入阴、阳、非离子等不同电荷基团。通过取代基间的相互协调作用与纸浆纤维结合在一起，并提高了纤维结合力，使得纸张强度性能得到改善。同时，由于淀粉微粒吸附松香、细小纤维等微细组份，一起沉积在纸页上，提高了纤维的留着率。本试验通过实验室小试，采用“HC—3”增强剂，添加于本厂日常生产用的未漂针叶木硫酸盐（Kp）化学浆，阔叶木烧碱法（Ap）半化学浆，废纸再生浆及三者混…     

纸浆特性对阳离子淀粉吸附作用的影响

通过对阔叶木和针叶木这2种不同浆种性质的研究表明,阔叶木比针叶木更容易吸附阳离子淀粉;研究还表明,纤维表面的性质是影响纤维对阳离子淀粉吸附效率的主要因素。     

硬脂酸淀粉酯的酶促合成及其乳化稳定性

硬脂酸淀粉酯是通过淀粉酯化而得到的乳化剂,它是由淀粉及其衍生物与硬脂酸、硬脂酸甲酯、硬脂酸酰氯或硬脂酸酸酐反应得到的酯化产品.硬脂酸淀粉酯由于疏水性有机碳链的引入,淀粉的疏水性增加,使之具备了亲油和亲水的双亲性质,可广泛应用于日用化学、食品、纺织化工,生物降解材料、医药等工业.目前合成硬脂酸淀粉酯所用方法主要是水媒法、溶剂法、熔融法等.本实验采用脂肪酶LipozymeTL IM为催化剂,马铃薯淀粉与硬脂酸为反应底物、焦磷酸钠为辅助剂,合成硬脂酸淀粉酯.在脂肪酶添加量为淀粉质量10%的条件下,考察了底物比,辅助剂用量,反应时间,反应温度对酯化效果的影响,确定了酶法合成硬脂酸淀粉酯的最佳条件:淀粉6.0g,硬脂酸20.0g,焦磷酸钠1.5g,反应时间42h,反应温度65℃,制得取代度为0.036的淀粉酯产品.所得淀粉酯具有良好的乳化能力.     

离子交换型纤维素纤维非织造材料的制备及其蛋白质吸附性能北大核心

通过对纤维素纤维非织造材料进行表面羧基化改性,制备得到具有离子交换功能的非织造材料基蛋白质吸附介质。研究了改性工艺参数对形貌结构、化学性质及力学性能的影响;并以溶菌酶为模板蛋白质,探究不同改性剂用量及改性温度条件下获得的非织造材料的蛋白质吸附性能。结果表明,当采用8%柠檬酸,以110℃热处理后,所得羧基化非织造材料具有良好的亲水性,对蛋白质的最高吸附量可达420 mg/g,且吸附过程符合Langmuir等温吸附模型和准二级动力学模型,是一种高效、环保的蛋白质吸附材料。     

PEI改性纸基材料的制备及其对水体主要污染物的去除

以麦草高得率浆为原料,戊二醛和聚乙烯亚胺为改性试剂,通过造纸工艺制得低成本、高湿强、具有优异吸附性能和油水分离性能的多功能纸基材料。改性纸基材料表面引入了大量氨基,含量可达3.33 mmol/g;其内部纤维间形成了共价键交联网络结构,湿抗张指数达到干抗张指数的29%。吸附实验研究表明,该纸基材料对吸附质的吸附动力学和热力学分别较好地拟合了准二级方程和Langmuir模型,其对刚果红和Pb²⁺的实际吸附容量分别为89.26和190.1 mg/g;理论最大吸附容量分别为91.04和232.4 mg/g。聚乙烯亚胺改性纸基材料对大豆油和正己烷的水下油接触角分别为152.5°和151.7°,具有水下超疏油性;此外,其对水包油乳液（平均粒径50 μm）的分离效率达到99.4%,膜通量达到12560 L/（m²·h）。     

柠檬烯—玉米淀粉复合膜的制备及性能研究

采用流延成膜法,利用玉米淀粉、柠檬烯及甘油制备一种新型可降解复合包装膜——柠檬烯—玉米淀粉复合膜。通过测试复合膜的力学性能、水蒸气透过率、吸水率等指标来分析复合膜的综合性能。结果表明,相比纯玉米淀粉膜,柠檬烯的加入使复合膜的透光率降低,力学性能和阻湿性能均得到改善,尤其是大大提高了复合膜的断裂伸长率。在玉米淀粉添加量20g,甘油添加量6g、柠檬烯添加量1.6g时断裂伸长率最高,为42.92%,且拉伸强度最高,为15.02MPa。该复合包装膜预期能够用作新型食品包装材料。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.