胶原纤维在离子液体中的溶解特性研究

研究了胶原纤维在氯代1-烯丙基-3-甲基咪唑([AMIM]Cl)离子液体中的溶解浓度。通过红外光谱(FT-IR)分析,结果表明:胶原纤维在离子液体中具有良好的可溶性溶解,属于直接溶解。     

两种氯代咪唑离子液体的合成及光谱特性研究

以N-甲基咪唑、氯丁烷和氯丙烯为原料,合成了两种离子液体1-丁基-3-甲基氯代咪唑([BMIM]Cl)和1-烯丙基-3-甲基氯代咪唑([AMIM]CI)用硝酸银滴定法测定其纯度分别为[BMIM]Cl 91.6%,[AMIM]CI 94.5%;并对两种氯代咪唑离子液体进行了紫外和红外光谱分析厕种离子液体在200～700 nm间都只有一个紫外吸收峰.[AMIM]Cl的λmax=212.0 nm,[BMIM]Cl的λmax=223.0 nm.     

筛选离子液体制备醋酸酯淀粉的研究

对玉米淀粉在三种离子液体中的溶解性进行了比较分析,其中离子液体氯化-1-烯丙基-3-甲基咪唑盐可以有效地溶解玉米淀粉.以氯化-1-烯丙基-3-甲基咪唑盐为均相反应介质,在无外加催化剂的存在下一步合成了取代度范围较宽的淀粉醋酸酯.考察了反应时间和酰化试剂用量对酰化程度的影响,并对醋酸酯淀粉的结构进行了表征.     

棉织物的离子液体溶解法回收

采用2种咪唑氯盐类离子液体溶解回收棉织物,比较棉织物在2种离子液体中不同温度下的溶解度。研究溶解温度对溶解时间和再生纤维素聚合度的影响,表征不同溶解时间下再生纤维素膜的结构及性能。结果表明,该方法可有效地回收再利用棉织物,110℃下1-烯丙基-3-甲基咪唑氯盐溶解质量分数为4%的棉织物再生纤维素膜表面平整,结构致密,断裂强度和断裂伸长率分别为38.5 MPa和6%。随着溶解时间的延长,再生纤维素膜结晶度不断降低,热稳定性变差,力学性能也随之下降。     

脱脂棉在离子液体中的溶解性能研究

有效地合成了离子液体1-烯丙基-3-甲基咪唑氯代盐([Amim]Cl),并探讨了脱脂棉纤维素在该离子液体中的溶解性能。测定了原、再生纤维素的聚合度,结果表明溶解前后纤维素的聚合度发生了很大变化,随着溶解温度的提高、时间的延长,再生纤维素聚合度降低;采用红外光谱、X-射线衍射及热重分析等手段对脱脂棉纤维素在离子液体[Amim]Cl中溶解和再生前后的结构变化进行了分析。结果表明,脱脂棉纤维素可直接溶解于离子液体[Amim]Cl而不发生其它衍生化反应。再生纤维素较原纤维素结晶状态由纤维素I转变为纤维素Ⅱ,再生后纤维素热分解温度降低,热稳定性略有下降。     

离子液体预处理改善脱墨浆性能的研究

以N-甲基咪唑、氯丁烷和氯丙烯为原料合成两种离子液体1-丁基-3-甲基氯代咪唑([Bmim]Cl)和1-烯丙基-3-甲基氯代咪唑([Amim]Cl)预处理混合办公废纸(MOW),分析其对MOW脱墨效果和成纸物理性能的影响。结果表明:离子液体处理可以改善纤维的某些表面特征,在绝干条件下经过离子液体预处理的MOW,可使其脱墨效果更好,白度明显提高,纤维形态更加均匀,相近打浆度下抄纸,抗张、耐折、耐破等物理指标也有所提高。     

羊毛角蛋白溶液的离子液体法制备

以离子液体1-烯丙基-3-甲基咪唑氯盐（[Amim] Cl）为主溶剂,以巯基乙醇为辅助试剂,研究了羊毛纤维在该溶剂体系中的溶解行为。正交试验结果表明,在m羊毛∶（[Amim] Cl）：m(巯基乙醇)=1：8.5：1、温度120℃、时间为7.5 h的条件下,羊毛纤维可全部溶解。分析可知,离子液体[Amim] Cl 的强极性作用利于打开纤维内部的氢键,巯基乙醇可有效拆开二硫键,再辅以机械搅拌的剪切作用,可使纤维解体直至溶解。     

废旧棉纤维素膜的制备及其结构与性能表征

废旧棉纺织品具有成本低、产量大等特点,其主要化学成分是纤维素,是制备再生纤维素制品的绝佳原材料。文章以废旧棉T恤为原料、以1-烯丙基-3-甲基咪唑氯盐([AMIM]Cl)离子液体为溶剂,成功地制备了透明再生纤维素膜,并进一步探究了不同凝固浴(水和乙醇)对其结构与性能的影响。实验结果表明:溶解再生后的纤维素发生晶型转变,未溶解部分仍保留原晶型;凝固浴种类显著影响再生纤维素膜的结构和性能,乙醇凝固浴制备的膜材料拉伸强度高达62 MPa,有望应用于包装领域。本研究实现了低成本纤维素原料废旧棉织物的高值利用。     

烟蒂醋酸纤维在离子液体[AMIM]Cl中的溶解与回收

为了回收烟蒂的醋酸纤维(CA),用氯代1-烯丙基-3-甲基咪唑([AMIM]Cl)离子液进行了溶解和回收烟蒂CA试验。结果表明:①适宜的溶解温度137℃,溶解时间70min,在此条件下,20g[AMIM]Cl可溶解0.76gCA;②纯CA与回收品的FT-IR谱图一致;③[AMIM]Cl离子液体可以循环使用5次。     

马尾松树皮在离子液体中的溶解及组分分离研究

针对目前树皮组分难以有效利用的问题,以离子液体1-烯丙基-3-甲基咪唑氯盐（［Amim］Cl）为溶剂,对球磨后的马尾松（Pinus massoniana L.）树皮进行溶解,随后以NaOH溶液及乙醇为沉淀剂,对树皮中的纤维素、木质素和半纤维素组分进行分级分离。结果表明,球磨24 h后的马尾松树皮在100℃、溶解5 h的条件下,能够在离子液体中完全溶解;再生后树皮中纤维素的晶型由I型转变为II型,结晶度降低,但再生后树皮主要化学成分与原料相同。采用1% NaOH溶液及乙醇溶液处理溶解后的树皮可有效分离得到纤维素、木质素和半纤维素,分离后各组分的化学结构未发生明显改变。离子液体经5次循环再利用后,其回收率依旧可以保持90%以上。     

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