淀粉酶对二次纤维的改性研究

淀粉酶是一种生物催化剂,酶的专一性决定其不会对纤维自身的强度造成不利的影响.用淀粉酶处理二次纤维,能水解纤维表面吸附的淀粉,增加纤维均匀分散的程度,有利于提高纸料的滤水速度、成纸强度.研究发现:当α-淀粉酶的用量为25IU/g绝干浆时,对二次纤维(OCC)的改性达到了最佳效果,成纸的环压指数为7.961 N·m/g,抗张指数为3.12N·m/g,挺度为1384mN·m.     

酶处理对废纸纤维的影响

含纤维素酶和半纤维素酶的酶制剂明显影响了实验室条件下废纸再制未漂针叶木硫酸盐浆的滤水性能和强度性能。采用中心组分设计法对浆料和其纤维组分的自变量、反应时间和酶用量进行了分析。统计数据分析表明滤水性能有明显的改善。酶处理对浆料物理性能的影响是;抗张指数和表观密度增加,撕裂指数和光散射系数下降。     

生物酶对二次纤维的改性作用研究

利用纤维素酶、半纤维素酶及复合纤维素酶对混合废纸浆进行了处理，比较了它们在优化条件下，不同酶及酶用量对浆料的作用效果，重点考察了酶处理对废纸浆滤水性能和抄造的纸张强度性质的影响。     

CPAM/膨润土双元体系在瓦楞原纸生产中的应用

利用动态滤水仪模拟瓦楞原纸乍产的湿部过程,研究了阳离子聚丙烯酰胺(CPAM)/膨润土双元体系对浆料留着、滤水及纸张性能的影响.结果表明,当CPAM用量低于0.02%(各化学品用量均对绝干浆量)时,CPAM/膨润土双元体系的助留助滤效果与CPAM单元体系的相当;当CPAM用量0.04%,膨润土用量0.2%时,CPAM/膨润土双元体系的助留助滤效果最好;在CPAM/膨润土双元体系中,CPAM宜在高速剪切前加入,而膨润土应在高速剪切后加入.一定范围内增加CPAM用量,可提高成纸的裂断长,但环压指数有所下降;当CPAM用量超过0.04%后,成纸的环压指数则随CPAM用量的增加而缓慢提高.     

PAE/NCC二元体系对纸张的增强作用

研究了聚酰胺多胺环氧氯丙烷/纳米晶体纤维素（PAE/NCC）二元体系对不同浆料所抄造纸张的增强效果,讨论了PAE/NCC二元体系中NCC的最佳用量及加入方式。研究结果表明，先PAE后NCC的添加方式对纸张的增强效果好于PAE与NCC先混合后添加的方式 ；PAE用量为1.0%、NCC用量为0.6%、采用先PAE后NCC的添加方式时，对针、阔叶木混合浆纸张，与原纸相比，干抗张指数增加了42.9%，湿抗张指数增加了13.3倍，撕裂指数增加了24.3%，耐折度增加了89.7%；对阔叶木浆所抄纸张，干抗张指数增加了74.7%，湿抗张指数增加了18.8倍，撕裂指数增加了28.7%，耐破指数增加了115%，耐折度增加了5倍。     

纤维素酶/天冬氨酸体系改善混合办公废纸强度性能的研究

针对办公废纸回用过程中出现的纤维品质下降、成纸强度低等问题,研究了纤维素酶/天冬氨酸体系处理混合办公废纸(MOW)后纸张的强度性能。结果表明,采用纤维素酶/天冬氨酸体系处理MOW可以明显提高纸张的强度性能,优化的工艺条件为:纤维素酶用量14. 74 U/g、天冬氨酸用量2. 19%、反应温度49°C、反应时间56 min。与未处理的空白样相比,最优酶促体系处理下MOW的纤维保水值升高36个百分点,纤维结晶度指数下降37. 58%,羧基含量提高32. 84%;纸张抗张指数与耐破指数分别提高了16. 05%和14. 39%。     

新型改性高岭土体系增强剂的研究

对高岭土进行了表面改性,检验了改性后的高岭土对纸张的增强效果.该增强剂对提高纸张的环压、耐破以及抗张性能具有很好的效果.当用量为0.8%时,环压指数可提高13.1%,耐破指数可提高25.4%.并尝试用高岭土刚性体/柔性链条/纤维三相体系理论对其进行解释.     

羧甲基羟乙基瓜尔胶在造纸中的初步应用

对羧甲基羟乙基瓜尔胶(CMHEG)在阔叶木漂白化学机械浆中的增强性能、助留助滤性能和纸张白度进行了研究。实验结果表明:当CMHEG用量为0.6%时,纸张获得较好的增强效果,相比原纸抗张指数提高21.3%,耐破指数提高38.1%,撕裂指数提高22.2%。该用量下,CMHEG对纸料的助留助滤有一定改善,而对纸张白度影响较小,其取代度对纸张的增强和助留助滤性能产生一定影响。     

生物酶预处理对废纸箱二次纤维打浆性能的应用研究

就生物酶预处理对废纸箱二次纤维打浆性能的影响进行了研究.结果表明,磨浆可显著提高废纸箱二次纤维的打浆度和机械强度;生物酶A用量为0.25％质量分数时与空白样相比,抗张指数、裂断长、耐破指数、撕裂指数以及环压指数等物理指标均有所提高,分别提高4.8％、4.4％、9.1％、3.3％和2.3％;生物酶B在酶用量为0.05％质量分数时,可在不影响纸张机械强度的情况下,改善纸浆的滤水性.     

CPAM-膨润土双元体系在新型硅酸钙加填纸上的应用

比较分析了CPAM-膨润土双元微粒助留体系对新型硅酸钙(FACS)和研磨碳酸钙(Gcc)加填浆料的留着、滤水及纸张性能的影响.实验结果表明,CPAM-膨润土双元体系应用于FACS加填纸中时,CPAM需求量高于GCC加填的;膨润土用量为0.1％时,CPAM用量的增加,能改善FACS加填纸料的留着性能,但对其滤水性能却有不利影响;CPAM用量为0.08％时,随着膨润土用量的增加,FACS加填纸料Zeta电位的下降比GCC加填的更快;膨润土的用量低于0.2％时,膨润土用量的增加对纸料的首程留着率和滤水性能都有利.CPAM用量为o.08％、膨润土用量为0.1％时,FACS加填纸白度与GCC加填纸张相当,但是不透明度比GCC加填纸高;FACS加填纸的抗张指数比GCC加填纸低11.2％,撕裂指数比GCC加填纸低21.0％;FACS加填纸张的松厚度比GCC加填纸高41.7％.加填纸张的扫描电镜对比发现,FACS能够较好地填充在纤维之间的缝隙中,可以看到纤维与填料之间有较好的交织.     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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 Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.