大豆油凹凸棒脱色及其返色的研究

采用凹凸棒作为吸附剂对大豆毛油进行脱色,以脱色率为指标,通过单因素试验和响应面分析对脱色条件进行优化,得到的最优脱色条件为脱色时间32min、脱色温度110℃、搅拌速率250r/min、脱色剂(凹凸棒)用量3%,此条件下,凹凸棒脱色大豆油的脱色率为71.83%。将凹凸棒脱色后的大豆油与普通脱色大豆油分别进行一定时间的105℃加热,对二者的色泽红值进行比较,结果显示,以凹凸棒作为吸附剂的脱色油脂较为稳定,不易返色。     

活性白土在单色光条件下对大豆油脱色特性的研究

以活性白土添加量为0.5％条件下,以VIS-450光与活性白土协同作用对大豆油进行脱色,以脱色率为指标,进行单因素实验,并采用响应面的方法进行分析,确定最佳的脱色条件为:电流强度21.3A,温度78.8℃,时间18.7 min,搅拌速度80r/min,得到大豆油的脱色率为97.8％.并且脱色后的油脂油色稳定,放置时间长,不易返色.     

米糠油脱胶和酸化凹凸棒土脱色工艺研究

采用正交实验研究了米糠毛油脱胶工艺,得到的酸法脱胶工艺最佳条件为磷酸添加量0.3%、脱胶温度70℃、加水量3%、反应时间40 min,此时米糠油脱胶率为87.7%。在此基础上,采用单因素实验考察了酸化凹凸棒土添加量、脱色温度、脱色时间对脱色率的影响。结果表明:在酸化凹凸棒土添加量5%、脱色温度110℃、脱色时间30 min条件下,米糠油脱色率达到96.6%。     

酱油渣油脂脱色工艺研究

近年来酱油渣油脂作为工业原料逐渐被大众重视起来。酱油渣油脂的颜色由于非常深而严重影响其作为原料油脂进一步加工。通过对酱油渣油脂脱色研究发现:普通脱色剂的脱色效果不理想,而改性凹凸棒土可以有效脱去酱油渣油脂的色素。通过单因素实验确定其最佳的脱色工艺条件是:搅拌速度为300r/min,改性凹凸棒土用量为油脂质量的75%,脱色时间60min,脱色温度90℃,油脂脱色率90%。在最佳脱色工艺条件下,脱色油脂的产率为65%。     

两段式脱色对大豆油脱色的影响

对油脂脱色工序进行研究,采用两段式脱色方法,即先用再生白土进行预脱色,再生白土添加量为0.7%,除去其中大部分热敏性物质,热敏物质脱除率达到96%;再进行第二步脱色选出最佳脱色条件:白土添加量1.2%,脱色时间30min,搅拌速度250r/min,脱色温度100℃,此条件下得出的脱色油颜色稳定不易返色。     

响应面试验优化油脂分段脱色工艺

利用多次吸附平衡可有效降低油脂的色泽原理,采用单因素试验探究分段脱色工艺对大豆油脱色效果的影响,然后通过响应面法获得最佳脱色工艺参数。在添加总量一定时,将活性白土分3 段进行添加,通过改变每段添加量比例,确定最佳吸附平衡的条件;在搅拌速率为150 r/min时,活性白土添加总量1.27%、脱色温度100 ℃、脱色总时间60 min,脱色油脂酸值为0.12 mg KOH/g,过氧化值为3.26 mmol/kg,色泽为黄18、红1.45,相对于常规脱色工艺活性白土用量减少9.29%,提高了油脂的精炼率。     

脱色吸附剂对大豆脱色油返酸返色的影响

为对油脂精炼脱色加工提供参考,以活性白土、凹凸棒土以及二者复配作为脱色剂对大豆中和油进行脱色,测定脱色油的酸值、色泽,并通过返酸返色试验探究脱色吸附剂对大豆脱色油返酸返色的影响。结果表明：脱色油酸值与活性白土添加量和复配脱色剂中活性白土质量分数呈正相关,与凹凸棒土添加量呈负相关;脱色剂添加量越多,脱色效果越明显,但在活性白土或凹凸棒土添加量超过3%时,脱色效果增加较少;随活性白土或凹凸棒土添加量的增多,脱色油返酸总体呈先降后升趋势;脱色油会有不同程度的返色,与活性白土相比,凹凸棒土脱色返色程度更高。综上,在脱色过程中,通过调整脱色剂添加量和配比可在一定程度上控制成品油的返酸返色程度。     

低反式脂肪酸含量大豆油脱色条件的优化

对大豆油脱色过程中反式脂肪酸含量进行研究,通过单因素试验与响应面分析,对影响脱色的主要工艺参数进行了优化.得到低反式脂肪酸大豆油脱色的最佳工艺参数为:脱色温度97℃,脱色时间30 min,脱色剂用量3.8%.在真空度0.095 MPa、搅拌速度220 r/min条件下,按最佳工艺参数脱色,得到大豆油反式亚油酸含量为1.18%,脱色率达到96.57%.     

菜籽油废白土预脱色—凹凸棒土复脱色的工艺研究

研究凹凸棒土对油脂脱色的效果及对油脂品质的影响,在单因素试验的基础上,采用正交优化试验法优化工艺条件,结果表明:影响凹凸棒土脱色效果的3个主要因素的主次关系为脱色时间活性炭添加量脱色剂用量;最佳工艺条件为预脱色15 min、复脱色15 min、废白土1.0%、凹凸棒土2.0%、活性炭0.1%时,综合脱色率为95.97%。     

响应面优化冷榨胡萝卜籽油吸附脱色工艺

本实验通过单因素和响应面法,研究了不同活性白土添加量、脱色时间和脱色温度对冷榨胡萝卜籽油脱色率的影响.研究表明:冷榨胡萝卜籽油吸附脱色的最佳工艺条件为活性白土添加量4％、脱色时间33 min、脱色温度62℃,在此条件下脱色率为68.33％,与理论脱色率68.49％接近,脱色后油脂澄清透亮,脱色效果良好.     

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.     

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