烟梗仿生物酶制浆与配抄工艺的研究

采用仿生物酶体系对烟梗原料预处理,制备烟梗化学机械浆。仿生物酶预处理烟梗原料的最佳条件:仿生物酶用量4.0mmol/kg,处理温度40℃,处理时间120min,最佳条件下制备的烟梗薄片的抗张指数和撕裂指数与空白样品相比,分别提高了24.53%和46.29%;处理的烟梗浆料与外加纤维配抄重组烟叶雪茄烟纸,其抗张强度为1.12kN/m,透气度为9.23μm/(Pa.s),伸长率为1.48%,达到了雪茄烟纸的物理指标要求;同时经感官评吸,与普通雪茄烟纸相比,评吸得分高2.25分,重组烟叶雪茄烟纸的杂气减少,刺激性降低,谐调性和香气量增加。     

烟草薄片型卷烟纸的制备及性能研究

以烟梗为原料制取的化学机械浆(CMP)与少最木浆纤维配抄烟草薄片原纸,经烟草萃取液涂布后制备烟草薄片型卷烟纸,并检测其相关物理性能和感官品质.根据烟草薄片型卷烟纸对抗张强度、透气度等物理指标的要求,通过优化打浆工艺,确定其最佳打浆度为:烟梗化机浆35°SR;未漂针叶本浆80°SR;漂白阔叶木浆40°SR;漂白麻浆70°SR;烟梗化机浆、未漂针叶木浆、漂白阔叶木浆、漂白麻浆的最佳配比为:75∶20∶2.5∶2.5,在此条件下,其抗张指数、透气度和伸长率分别为39.7 N·m/g,10.21μm/(Pa·s)和1.41％;经评吸实验感官评价,与普通雪茄烟纸相比,烟草薄片型卷烟纸的木质杂气减少,刺激性降低,品质得到提升.     

烟梗浆的漂白工艺研究

采用化学机械法对烟梗原料预制浆和后续漂白处理,得到漂白烟梗纸浆,同时对烟梗浆料的漂白工艺进行初步探讨,实验结果表明：①对烟梗薄片的物理力学性能,H2O2用量8％,反应温度80℃,反应时间120min是合适的;②对烟梗薄片的白度性能,H2O2用量8％,反应温度70℃,反应时间90min是合适的。     

烟秆CMP浆配抄包装用薄页纸的研究

通过对烟秆全杆的纤维形态、化学组成进行分析,从预浸渍时间、温度、药品用量3个方面探索了烟秆CMP浆的制浆工艺,检测了制浆得率、白度以及所抄纸张的抗张强度,获得了实验条件下较佳的工艺条件。在该工艺条件下所得烟秆CMP浆与漂白阔叶木浆进行配抄实验,结果表明,烟秆CMP可用于配抄包装用薄页纸,添加量为20%时,所抄纸张的抗张强度和伸长率接近卷烟包装用内衬原纸的要求。     

低定量造纸法再造烟叶基片浆料配比的优化

在对再造烟叶浆料进行纤维特性分析前提下,采用单因素实验方法,对再造烟叶浆料各组分配比进行研究。结果表明:在抄造(30±1)g/m2的低定量造纸法再造烟叶基片时,当轻质碳酸钙(PCC)填料用量为15%、木浆纤维用量为20%(即烟草浆∶木浆纤维∶PCC填料=65∶20∶15,其中烟草浆料中烟梗浆∶烟末浆为7∶3)时,再造烟叶基片的松厚度、抗张强度及透气度综合达到最优水平。     

杨木加工剩余物制漂白化机浆及配抄轻型纸的研究

以苏北地区的杨木加工剩余物为原料,选用我国自主研发的双螺杆磨浆机进行了漂白化学机械法制浆性能及配抄轻型纸的研究。研究结果表明：以杨木加工剩余物为原料,采用双螺杆磨浆制浆流程制得的纸浆具有优良的松厚性能、物理强度性能和光学性能。在H2O2用量为5.0%、NaOH用量为4.5%浸渍条件下,制得杨木加工剩余物漂白化机浆的白度可以达到78%ISO以上,加拿大游离度为100mlCSF时,纸浆的松厚度可以达到2.1cm^3/g以上,抗张强度可达38N·m/g以上。以该条件制得加拿大游离度为100mlCSF的杨木加工剩余物漂白化机浆,配以10%～20%的漂白针叶木浆,抄造的轻型纸质量指标可以达到轻工行业标准（QB/T2809-2006）中轻型纸的质量指标要求。     

造纸法烟草薄片打浆工艺和助留助滤剂的研究

首先对国内外烟草薄片成品的性能差异进行了分析比较,针对国内造纸法烟草薄片存在的质量问题,采用KRK磨浆机,进行烟草浆不同磨浆浓度条件下（4%、8%、18%、30%）的磨浆实验,并将由烟梗和碎烟制备的烟草浆与木浆配抄烟草基片,考察了磨浆浓度、添加不同助留助滤剂对烟草基片松厚度、干/湿抗张强度以及配抄浆料留着和滤水性的影响。结果表明：采用低浓（4%）磨浆、添加适量（0.6%左右）的壳聚糖抄造,所得烟草基片的综合质量较好,配抄浆料的留着和滤水性能好。     

变性淀粉在高速纸机上的应用试验

我们在实验室进行了多种变性淀粉的应用试验，获得了令人满意的结果。于是，我们先后在1760、2362及3940纸机上进行了生产性试验，试验的目的旨在纸机上验证手抄纸实验中变性淀粉的有效作用。由于篇幅关系，这里仅介绍在3940纸机上的试验情况。我厂3940纸机系飘片满流式流浆箱叠网复合压榨多缸纸机。产品为用漂白KP获苇浆。漂白KP马尾松木浆及H2O2漂白的马尾松磨石磨木浆配抄的52g／m2胶印书刊纸。使用滑石粉作填料，白色松香胶作施胶剂，硫酸铝作胶料沉淀剂。纸机车速为530～560m／min。1磷酸酯淀粉在3940纸机上的应用试验1．1试验条件…     

尾叶桉硫酸盐法制浆造纸性能探索

进行了尾叶桉木片硫酸盐法蒸煮,纸浆无元素氯漂白、打浆及配抄性能的探索,得出较合适的蒸煮条件为:用碱量(Na2O计)18%,硫化度25%,液比1∶4,升温1.75h, 保温2.5h,最高温度168℃(120℃小放气),成浆卡伯值为22.58,得率45.2%.漂白采用ODQP四段漂,成浆白度达87.2%ISO.经瓦利打浆机打浆55min可以打到35°SR.漂白桉木浆与甘化浆板配比为3∶7时,配抄70 g/m2的胶印书刊纸,可以达到A等的强度、白度和不透明度等指标的要求.     

产品天地

●四川南充红光纸厂用硫酸盐桑皮浆抄造出紧度、裂断长,撕裂度及外观质量较好的2号打字纸。(谢华) ●全棉杆漂白浆配抄胶印书刊纸由山东造纸工业研究所研究的全棉杆漂白浆代替进口木浆配抄胶印书刊纸项目今年4月通过省级鉴定。用20%的漂白全棉杆浆和80%漂白麦草浆配抄胶印书刊纸,成纸     

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.     

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.     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.