酸解羟丙基复合变性淀粉的制备及性能研究

本文以马铃薯淀粉为原料,以盐酸为酸解剖,环氧丙烷为醚化剂,无水硫酸钠为膨胀抑制剂,氢氧化钠为催化剂,对酸解羟丙基复合变性淀粉的制备和性能进行了研究。考察了环氧丙烷用量、无水硫酸钠用量、氢氧化钠用量、反应温度、反应时间对醚化反应的影响。采用流度计测定酸解淀粉的酸解度,分光光度计测定酸解羟丙基复合变性淀粉的取代度。试验结果表明,盐酸用量增大,酸解淀粉的黏度显著减小;增加环氧丙烷和氢氧化钠用量,升高反应温度和增加反应时间均有利于增大酸解羟丙基复合变性淀粉的取代度。     

酸解醚化复合变性淀粉浆料的性能研究

研究酸解-醚化复合变性淀粉浆料的上浆性能。测试了自行制备出的酸解-醚化复合变性淀粉浆料的浆液性能和浆膜性能,并通过上浆试验分析了其实际浆纱及织造效果。试验结果表明:所制备出的酸解-醚化复合变性淀粉浆料具备较好的物化性能,对涤棉具有较好的黏附性,浆膜断裂强度大,断裂伸长率、耐磨性和耐屈曲性均优于一般淀粉;该复合变性淀粉浆料可部分替代PVA进行浆纱生产,且不低于原有上浆效果。     

交联羧甲基复合变性淀粉合成研究

以玉米淀粉为原料,环氧氯丙烷为交联剂、氯乙酸为羧甲基化试剂,在碱催化条件下合成交联羧甲基复合变性淀粉。通过工艺条件优化及结果分析,筛选出较佳合成条件为:交联剂用量为淀粉量的0.1%,m(淀粉)∶m(氯乙酸)∶m(氢氧化钠)=1∶0.47∶0.35,醚化时间为3 h,醚化温度45℃。获得了取代度在0.4左右,黏度可高于15 000 mPa·s(4%水溶液)的交联羧甲基复合变性淀粉。     

一步法制备蜡质玉米复合变性淀粉工艺研究

以蜡质玉米淀粉为原料,环氧丙烷为醚化剂,三偏磷酸钠为交联剂,氢氧化钠为催化剂,无水硫酸钠为膨胀抑制剂,采用一步法湿法工艺制备了蜡质玉米复合变性淀粉。研究了环氧丙烷、三偏磷酸钠、氢氧化钠、无水硫酸钠用量对产品取代度和反应效率的影响,结果表明:交联羟丙基复合变性淀粉反应时膨胀抑制剂无水硫酸钠的适宜用量为13%,催化剂Na OH适宜用量为1.2%,醚化剂适宜用量为10%,反应时间为16 h,反应温度为45℃;三偏磷酸钠用量对产品取代度和反应效率影响较小;并制备了羟丙基复合变性淀粉,为蜡质玉米淀粉的应用和变性淀粉的开发提供了理论参考。     

低取代度羟丙基木薯淀粉的制备

羟丙基木薯淀粉为优良的食品用变性淀粉。本文研究用环氧丙烷制备羟丙基木薯淀粉的最佳反应条件,着重研究了淀粉乳浓度、环氧丙烷用量、反应温度和时间对醚化程度和反应效率的影响规律。结果表明:增高淀粉乳浓度能提高醚化程度和反应效率;增加环氧丙烷用量能加速醚化反应,提高取代度,但使反应效率降低;一定范围内升高反应温度,延长反应时间,醚化程度和反应效率随之增高。     

水相中羧甲基淀粉的制备研究

本文以玉米淀粉为原料，采用酸化-醚化复合变性的方法在水相中制备高取代度低粘度羧甲基淀粉（CMS）．棵讨了酸化时间、液固比、NaOH用量、ClH2COOH用量、醚化反应时间、反应温度对美甲基化过程的影响。研宛发现，对原淀粉进行酸化，可以在不增加其它反应试剂用量的基础上提高产物的取代度，但是酸化时间不应过长。同时得到了其它单因素变化时各自对产物取代度的变化趋势，为进一步优化反应条件提供了依据。     

羟丙基糯玉米淀粉POCl3 交联复合变性条件的研究

经羟丙基化和POCl3交联复合变性的糯玉米淀粉在国外已广泛的应用于多种食品体系，国内还未见有同类产品上市。本文以自制的羟丙基糯玉米淀粉为起始原料，对其进行POCl3交联复合变性，确定了最佳反应条件：POCl3用量为0．018％、反应pH值11．6、NaCl用量为1．2％、反应时间40min。     

复合变性对淀粉性质的影响研究

复合变性淀粉是近年来研制开发的一类新型变性淀粉,是将淀粉采用两种或两种以上的变性方法而获得的淀粉衍生物.与单一变性淀粉相比,表现出更优越的物理化学性能,从而将会大大拓宽变性淀粉的工业应用领域.本文概述了几种典型的复合变性淀粉,如氧化淀粉、酯化淀粉、醚化淀粉及接枝共聚型复合变性淀粉的国内外研究现状,并展望了该类变性淀粉的研究方向及其潜在的发展前景.     

交联作用对复合变性玉米淀粉的合成及热黏度的影响

本文以市售的玉米淀粉为原料,以环氧丙烷为醚化剂,以三偏磷酸钠为交联剂,以取代度和反应效率为评价指标研究交联作用对复合变性玉米淀粉的合成及热黏度的影响。结果表明交联剂用量、交联时间、交联温度和交联pH值是影响合成复合变性玉米淀粉的主要因素,交联一羟丙基复合变性玉米淀粉的热黏度随交联度的升高而增加。     

“醚化—氧化—酯化”多元变性淀粉的研制

以木薯淀粉为原料,采用"醚化-氧化-酯化"多元变性工艺技术制备高浓度淀粉胶黏剂。研究探讨了醚化剂用量、醚化反应温度、醚化反应时间、氧化剂用量、酯化剂用量、酯化反应温度、酯化反应时间等反应条件对淀粉糊液性能的影响。确定了最佳的工艺条件:醚化剂用量2%;醚化反应温度48-50℃;醚化反应时间1.5-2小时;氧化剂用量为3-5%;酯化剂用量3-4%;酯化反应温度38-40℃;酯化反应时间2.5-3小时。所得多元变性淀粉糊液低温流变性好、耐老化性能好、保水性能优,能满足造纸及纸制品行业高浓度胶粘剂应用的需要。     

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.     

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.     

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 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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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