预处理和强化对桉木常规KP浆氧脱木素的改善效果

研究了几种预处理和强化方法对桉木常规KP浆氧脱木素的改善效果.表明在一定条件下通过对氧脱木素过程进行强化或在氧脱木素前对浆料进行预处理,可以改善氧脱木素效果.与单纯的氧脱木素相比,氧脱木素时添加0.8%H2O2或6%甲醇(对浆料总液量的体积比)进行强化,氧脱木素程度可分别从44.9%增加到50.6%和49.4%,纸浆白度增加6.8%ISO和5.1%ISO,而纸浆粘度仅分别多降低2.35%和1.72%.在氧脱木素前用1.5%KMnO4预处理浆料,氧脱木素程度增加20.3%,白度提高12.6%ISO,而粘度仅下降2.8%.利用HNO3/NaNO3进行预处理时,HNO3/NaNO3用量有一最佳值,且宜采用短时间高温预处理的方式进行.使用过氧酸预处理桉木KP浆的适宜条件为过氧酸用量3%(H2SO5计)、温度60℃、时间30min、浆浓12%、pH5.0,在预处理前首先用0.5%DTPA进行螯合预处理.此外,若将HNO3/NaNO3或KMnO4预处理与H2O2强化氧漂相结合,可取得进一步降低氧漂浆卡伯值、提高纸浆白度和保持较高纸浆粘度的良好效果.     

桉木常规KP浆和RDH硫酸盐浆的氧脱木素

对桉木常规KP浆和RDH硫酸盐浆的氧脱木素进行了研究和对比.确定了氧脱木素的最佳条件,结果表明,常规KP浆和RDH硫酸盐浆在适宜的条件下经氧脱木素后,纸浆卡伯值分别降低58.2%和42.25%,纸浆白度分别增加了29.5%ISO和22.4%ISO,达到56.8%和63.0%.而纸浆的粘度变化不大.综合而言,氧脱木素对常规KP浆和RDH浆的卡伯值、白度和脱木素选择性的影响规律类似,但由于RDH浆的初始卡伯值和粘度较低,因而氧脱木素时可以采用相对温和的反应条件,且RDH氧漂浆的粘度也相对较低.     

桉木常规KP浆和RDH浆的氧脱木素研究(Ⅴ)--ClO2预处理对RDH浆氧脱木素的改善效果

研究了ClO2预处理对桉木RDH硫酸盐浆氧脱木素的影响。结果表明,在桉木RDH浆氧脱木素前,用少量ClO2,在低温下对浆料进行短时间的预处理,即可改善氧脱木素效果,降低氧漂浆的卡伯值,有效增加纸浆白度(如用0.3%ClO2,40℃下预处理5 min,脱木素程度增加10.6%,白度提高7.87个百分点),而预处理对纸浆黏度影响不大。     

桉木常规KP浆和RDH浆的氧脱木素研究(Ⅲ)--HNO3/NaNO3预处理对常规KP浆氧脱木素的影响

研究了HNO3/NaNO3预处理对桉木常规KP浆氧脱木素的改善效果.研究表明,在氧脱木素前,用HNO3/NaNO3对浆料进行预处理,可以有效改善后续氧脱木素段的脱木素效率,提高氧脱木素的选择性.但HNO3/NaNO3用量有一最佳值,且宜采用短时间高温预处理的方式进行.若将HNO3/NaNO3预处理与H2O2强化氧脱木素相结合,可取得进一步降低氧脱木素浆卡伯值、提高纸浆白度和保持较高纸浆粘度的良好效果.     

过氧酸预处理对杨木硫酸盐浆氧脱木素的影响

在适宜的条件下，杨木硫酸盐浆经过氧酸Pxa预处理，氧漂后脱木素程度增加，浆的白度及脱木素的选择性提高，而对粘度的影响不大。混合过氧酸（Pxa）预处理的效果好于过氧乙酸。氧漂后的浆料经短程序无氯漂白，可制得高白度纸浆（经DEpP程序，ISO白度达85．7％），并对各种浆的物理性能进行了分析。     

桉木常规KP浆和RDH浆的氧脱木素研究(Ⅰ)--常规KP浆和RDH浆的氧脱木素效果

对桉木常规KP浆和RDH硫酸盐浆的氧脱木素进行了研究和对比，确定了氧脱木素的最佳条件。结果表明，常规KP浆和RDH硫酸盐浆在适宜的条件下经氧脱木素后，纸浆卡伯值分别降低58．2％和42．25％，纸浆白度分别增加了29．5％ISO和22．4％ISO，达到56．8％ISO和63．O％ISO，而纸浆的粘度变化不大。综合而言，氧脱木素对常规KP浆和RDH浆的卡伯值、白度和脱木素选择性的影响规律类似，但由于RDH浆的初始卡伯值和粘度较低，因而氧脱木素时可以采用相对温和的反应条件，且RDH氧漂浆的粘度也相对较低。     

硫酸盐苇浆氧脱木素的研究

将硫酸盐苇浆分别用硫酸和六偏磷酸钠预处理,再进行一段和两段氧脱木素,测定了纸浆中金属离子的含量,以及纸浆的卡伯值、粘度和白度。结果表明,用硫酸和六偏磷酸钠预处理都能有效的去除硫酸盐苇浆中的过渡金属离子,并且六偏磷酸钠预处理能很好的保留利于氧脱木素的镁离子。与一段氧脱木素相比,两段氧脱木素更有利于木素的脱除,预处理后的硫酸盐苇浆经两段氧脱木素后,卡伯值降低了60％左右,白度增加了40％以上。并且经六偏磷酸钠预处理后的纸浆具有更好的氧脱木素选择性,两段氧脱木素后纸浆的白度达到59．7％,有利于TCF漂白的实现。     

桉木常规KP浆和RDH浆的氧脱木素研究(Ⅱ) --预处理和强化对常规KP浆氧脱木素的改善效果

研究了预处理和强化对桉木常规KP浆氧脱木素效果的影响。结果表明，在氧脱木素时添加H2O2和甲醇进行强化，或在氧脱木素前采用KMnO4对浆料进行预处理，对氧脱木素都有良好的改善效果。与单纯的氧脱木素相比，使用0．8％H2O2、6％甲醇(对浆料总液量的体积百分比)和1．5％KMnO4．浆料脱木素程度分别增加了5．7％、4．5％和20．3％，纸浆白度分别增加6．8％ISO、5．1％ISO和12．6％ISO，而纸浆粘度仅分别多降低2．35％、1．72％和2．8％。采用KMnO4预处理与H2O2强化相结合，可以更有效地改善氧脱木素效率，进一步提高纸浆白度。     

桉木常规KP浆和RDH浆的氧脱木素研究(Ⅵ)--预处理和强化对RDH浆氧脱木素的改善效果

研究了HNO3/NaNO3预处理、KMnO4预处理和H2O2强化对桉木RDH硫酸盐浆氧脱木素的改善效果,并与常规KP浆进行了对比。结果表明,少量H2O2对RDH浆氧脱木素具有良好的强化效果,较佳的H2O2用量为0.8%。在制备低卡伯值纸浆时,采用RDH蒸煮与H2O2强化的氧脱木素相结合的制浆方法比采用常规KP蒸煮与H2O2强化的氧脱木素相结合的方法更有利于保护纸浆的黏度。在氧脱木素前对RDH浆进行HNO3/NaNO3或KMnO4预处理也有利于改善氧脱木素的效果,提高残余木素的脱除程度,其中KMnO4预处理还可以较明显地提高纸浆白度。但相对而言,这两种预处理方式更适合于用来改善常规KP浆这类残余木素含量较高纸浆的氧脱木素。     

双氧水强化两段氧脱木素的应用

对洗筛后未漂细浆进行了H_2O_2强化氧脱木素研究,并对氧脱木素后纸浆采用XH工艺漂白。研究和生产结果均表明,在氧脱木素过程中添加质量分数27.5%的双氧水折百加入量为1.0%～1.5%,可以有效降低氧脱木素后纸浆硬度,同时提高了纸浆白度,脱木素浆再经XH漂白后,漂白浆白度达到81%ISO以上,完全能够生产抄造文化用纸所需的80%ISO以上高白度纸浆。     

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.