碎浆工艺对旧杂志纸脱墨浆性能的影响

以旧杂志纸为原料,以脱墨浆白度和抗张指数为脱墨浆的主要性能指标,利用正交试验探究了旧杂志纸脱墨的最佳碎浆工艺。结果表明,最佳脱墨工艺条件为:碎浆浓度12%,碎浆时间40min,碎浆温度55℃。在该最佳工艺条件下,脱墨浆的白度可达77.0%ISO,抗张指数为40.0 N·m/g,可满足多种用途。     

旧报纸漆酶脱墨工艺的研究

对旧报纸漆酶脱墨工艺进行了研究.得出了最佳工艺条件:漆酶用量10 LAMU/g,介体(Violuric Acid)用量0.5%,碎浆时间30min,保温时间15 min,通氧气,温度55～60℃.在此条件下进行脱墨,所得脱墨浆白度与对照浆相比有所降低,但可漂性提高.漂白后浆白度达到52.4%ISO,与对照浆相比提高4.2%ISO.此时裂断长为2.16 km,撕裂指数为7.01mN·m2/g,与对照浆相比分别提高了20%和13%.     

办公废纸化学法脱墨工艺条件的研究

通过控制变量法研究办公室废纸脱墨工艺,探究温度、化学药品对纸张脱墨效果的影响,由白度及脱墨纸张的物性来表示;并确定脱墨的最佳温度,在最佳温度条件下,用浮选的脱墨方法来研究脱墨化学品的最佳用量。结果表明,采用较高的脱墨温度有利于办公室废纸的脱墨;氢氧化钠对办公室废纸的有效脱墨是必需的;硅酸钠可以明显促进油墨的脱出;过氧化氢的加入对脱墨浆的白度提高有较大贡献。办公废纸化学法脱墨的最佳工艺：温度60℃,硅酸钠3％（对绝干浆）,氢氧化钠1％（对绝干浆）,过氧化氢：1％（对绝干浆）,EDTA：0,4％（对绝干浆）,肥皂：0．5％（对绝干浆）。在最佳脱墨条件下脱墨纸浆的白度为81．37％、耐折度为8次、抗张指数为327．93N·m／g、耐破指数为1．563kP·m2、撕裂指数为6．246mN·m2／g。     

旧杂志纸脱墨工艺的优化

以旧杂志纸为原料,通过控制变量法进行单因素分析,研究碎浆浓度、时间及温度对脱墨效果的影响,并用正交实验优化了脱墨工艺条件。其最佳的脱墨工艺条件为:碎浆浓度12%,碎浆时间40 min,碎浆温度50℃;在该条件下,旧杂志纸脱墨浆的ERIC值、白度、抗张指数和耐破指数分别为123.72 mg·kg-1、77.19%、39.45 N·m·g-1和2.96kPa·m2·g-1。     

自制聚醚脱墨效果的研究

利用自制的系列聚醚对旧报纸进行脱墨实验,通过测定表面活性剂的表面张力及其与油墨的接触角和黏附功,探讨了聚醚结构和表面活性对脱墨浆白度的影响.研究发现,聚醚HLB值不宜过大,其相对分子质量对脱墨浆白度的影响不大,表面活性是影响脱墨效果的主要因素.当聚醚和油墨的接触角小于33°、黏附功在58 mN/m左右时,对旧报纸的脱墨效果较好,脱墨浆的白度值可提高6%～8%.     

纤维素酶脂肪酶处理旧新闻纸脱墨效果比较

纤维素酶和脂肪酶对ONP都有一定的脱墨作用,在相同工艺流程及各自的最佳脱墨条件下,脂肪酶处理ONP脱墨效果明显优于纤维素酶;脂肪酶比纤维素酶处理后脱墨浆白度高出1.82％ISO,残余油墨含量降低了3．7mm2／g,撕裂指数高1.1 mN·m2／g,断裂长高0.15 km,脱墨率高18％。     

高产木聚糖酶对废新闻纸脱墨的补偿工艺研究

为探讨实验室培养高产木聚糖酶(酶活1792.67 IU/mL)在废新闻纸脱墨中的环境适应能力,在木聚糖酶脱墨适宜工艺基础上进行了酶用量补偿研究。研究发现,酶脱墨适宜条件为:酶用量5.0IU/g、酶处理时间50min、反应温度45℃、反应pH值5.0,此时脱墨浆料白度可提高2.04%ISO,残余油墨面积降低了17324mm~2/m~2。通过增加酶用量的方式来补偿实际应用中由于低温、高碱环境对酶活造成的损失,研究结果表明在脱墨温度为20℃、pH值为7.0时的脱墨浆白度仍可提高1.94%ISO,残余油墨面积降低了17546mm~2/m~2,达到适宜脱墨工艺条件下的脱墨效果。     

复合酶用于废纸浆脱墨

以纤维素酶、酯酶等组成的复合酶对美废纸浆进行脱墨,得到了美废纸浆脱墨优化的工艺条件为:碎浆浓度12.5%,碎浆时间20min,碎浆温度35～40℃,pH8～9,吨纸复合酶用量200g和吨纸助剂用量800g。在此工艺条件下,#3美废纸浆经脱墨后纸浆白度达到43.5%,纸浆白度高于化学脱墨。     

新闻纸化学法脱墨工艺条件的研究

主要研究了新闻纸化学法脱墨过程中各个因素对脱墨效果的影响,根据结果优化出最佳工艺条件,得到白度和物理性能优良的纸浆,实验发现,一定的脱墨温度和脱墨药品不仅能够提高脱墨纸浆的白度,也能够提高脱墨纸浆的强度性能,表现为脱墨后的纸浆的耐折度、抗张指数、耐破指数、撕裂指数均有增加。实验得出废旧新闻纸脱墨的最佳工艺条件为：脱墨温度为60℃,NaOH用量为1．0％,H202用量为1．0％,Na2SiO,用量为3．0％,肥皂用量为0．5％,EDTA用量为0．4％。在最佳脱墨条件下脱墨纸浆的白度为56．2％、耐折度为18次、抗张指数为37．14N·m／g、耐破指数为2．08kP·m2、撕裂指数为9．7mN·m2／g。     

采用响应面法优化旧报纸的裂褶菌粗酶液脱墨

利用裂褶菌(Schizophyllum Commune)在限氮培养条件下产生的粗酶液对旧报纸进行脱墨,采用响应面法中的Box-Behnken实验设计,对影响脱墨的主要因素酶用量、温度和pH值进行优化,得到了用于预测脱墨浆有效残余油墨浓度(ERIC值)和白度值的数学模型。模型方差分析和响应面曲线分析表明,pH值对裂褶菌粗酶液脱墨效果的影响最为显著。优化结果显示,当酶用量0.20 IU/g、温度52.5℃和pH值6.5时,脱墨浆有效残余油墨浓度最低,为208.0 mg/kg;当酶用量0.24 IU/g、温度52.2℃和pH值6.5时,脱墨浆白度最高,为53.3%。验证实验证明了模型优化的准确性。     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.     

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%.