大豆油酶法脱胶和硅胶吸附脱皂效果研究

利用PLA1脱除大豆毛油中的磷脂,再用硅胶吸附脱除大豆油中的残磷和残皂。以酶法脱胶后含磷量、硅胶吸附脱皂后的含磷量和含皂量为评价指标,研究酶法脱胶及硅胶吸附脱皂对大豆油脱胶脱皂效果的影响。结果表明：在大豆油pH 5.5～6、去离子水添加量3%、反应时间6～8 h的脱胶条件下,酶法脱胶效果随PLA1添加量的增加而提高,PLA1添加量分别为50、75、100 mg/kg时,脱胶大豆油中含磷量分别从566.36、538.02、562.76 mg/kg降至44.67、18.99、17.01 mg/kg,再添加油质量0.1%的SORBSIL R92硅胶,大豆油含磷量分别降至41.21、16.35、15.42 mg/kg,含皂量分别从37、23、14 mg/kg降至14、8、5 mg/kg。酶法脱胶后大豆油酸值和过氧化值有所升高,3个油样的酸值（KOH）平均升高0.63 mg/g,过氧化值平均升高0.007 g/100 g。硅胶吸附脱皂也造成大豆油酸值和过氧化值有所升高。     

响应面法优化无水脱皂工艺的研究

研究了废白土脱除大豆油中皂脚的方法,并利用响应面对其工艺进行优化实验。将大豆脱胶油加碱后油置于离心脱皂机中脱除大部分皂脚,再加入废白土作为吸附剂吸附残皂,通过单因素实验和响应面优化确定了无水脱皂的最佳工艺条件为：废白土的添加量0．5％,吸附的最佳温度100℃,脱皂时间53min,脱酸油水分含量0．4％,搅拌速度93r／min,在最佳条件下脱皂,油中含皂量为25．3mg／kg。     

废白土脱除碱炼脱酸大豆油中残皂工艺条件的研究

以废白土为吸附剂,对碱炼脱酸大豆油中残皂的脱除进行了研究。在单因素实验的基础上进行响应面优化实验设计,确定了脱皂的最佳工艺条件为:吸附温度82℃,废白土添加量0.5%,吸附时间20 min。在最佳条件下,脱皂大豆油中的残皂量为29.09 mg/kg,脱皂率达91.81%,且短时期(3 d)内存放的废白土脱皂率大于85%。     

油脂碱炼过程中无水脱皂工艺改造

在原600 t/d碱炼工艺中将常规水洗脱皂工艺调整成无水脱皂工艺,增加2台过滤机,减少1台水洗离心机,采用两次脱色工艺,添加硅藻土0.1% ～0.2%,脱去脱皂油中的磷脂和皂类,取消水洗,可减少废水排放40 kg/t,白土用量增加1.23 kg/t,减少用电0.93 kW·h/t,精炼油得率提高约0.1%,减少加工费8.99元/t.白土脱色后油中残磷量1～3 mg/kg,残皂量为0.     

新型磷脂酶用于米糠油酶法脱胶的研究

探讨了反应时间、柠檬酸添加量、酸碱配比、水洗和脱色等条件对米糠油酶法脱胶油含磷量的影响,得到以下优化条件:反应时间5 h,柠檬酸添加量0.06%,柠檬酸:NaOH为1:0.4,8 000r/min混合速度,3%白土脱色,在优化条件下酶法脱胶可使脱胶油含磷量降低至25 mg/kg左右,经过3%白土吸附脱色含磷量可降低至7 mg/kg以下,可以满足物理精炼的要求.另外,水洗可小幅度降低脱胶油含磷量;和其他植物油酶法脱胶相比,米糠油酶法脱胶对酸碱配比的要求相对较低.     

响应面试验优化玉米油冷冻吸附法脱皂工艺

对玉米油冷冻吸附法脱皂工艺进行研究,考察脱胶脱酸玉米油含皂量、含水量、硅藻土添加量、搅拌速率和养晶时间对冷冻吸附法脱皂后清油中残皂量的影响。通过单因素试验和响应面优化确定冷冻吸附脱皂的最佳工艺条件为：含皂量321 mg/kg、含水量0.4%、硅藻土添加量0.4%、搅拌速率12 r/min、养晶时间27 h。在此条件下,清油中的残皂量为23.1 mg/kg,脱皂率为92.8%。对冷冻吸附法脱皂工艺和常规水洗工艺的清油品质进行对比,结果表明,这两种方法脱皂的效果相当,但冷冻吸附脱皂不经过水洗过程,无废水排放,符合节能环保的工艺要求,并且利用冷冻吸附法脱皂能够完成前脱蜡的目的,简化了加工工艺。     

无水脱皂工艺在油脂精炼中的应用

分析脱皂离心机出油含皂和吸附剂用量对无水脱皂工艺的影响,确定合适的无水脱皂工艺参数,同时对无水脱皂工艺和常规水洗工艺的中和油品质进行了对比。结果表明,无水脱皂工艺在含皂300 mg/kg左右,吸附剂添加量为0.10%时可以顺利进行;无水脱皂工艺中和油品质优于常规水洗工艺,无水脱皂工艺的节能减排效益显著。     

专用硅胶在油脂精炼生产中的应用研究

利用专用硅胶对油脂进行吸附脱胶、吸附脱皂、吸附脱色及脱除氯离子,通过对工艺条件和脱除效果的研究,评价其在油脂精炼生产中应用的可行性。结果表明:利用SORBSILR92硅胶对浓香花生油进行吸附脱胶,在硅胶添加量0. 5%、吸附温度80℃、吸附时间15 min条件下,磷脂脱除率为96. 2%,且脱胶油色泽清亮、风味保留好;利用SORBSILR92硅胶对碱炼脱酸后的大豆油进行脱皂处理,可使大豆油含皂量从130. 7 mg/kg降至未检出,与水洗脱皂相比,不仅能明显降低含皂量,还实现了脱皂过程的废水零排放,减少了脱皂过程的油脂损耗;利用SORBSILR40F在优化条件下对大豆油脱色(先向待脱色油中添加0. 08%的SORBSILR40F硅胶,吸附反应后再添加1. 57%的活性白土)后,其含磷量明显低于单纯活性白土脱色油,并且脱臭油的色泽、氧化稳定性也优于单纯活性白土脱色脱臭油;利用SORBISILR40F硅胶和SORBSILR92硅胶在100℃、20 min条件下对大豆油进行吸附处理,大豆油中氯离子含量分别降低28. 47%和18. 98%,这对防范和降低油脂脱臭过程3-氯丙醇酯和缩水甘油酯的形成是有利的。综上,专用硅胶SORBSILR92和SORBSILR40F在油脂精炼工艺技术的改进发展方面具有很好的应用前景。     

响应面试验优化玉米油二次脱皂新工艺

利用玉米油含蜡特性,即在低温脱蜡过程中,皂粒以晶核状态吸附蜡质结晶脱蜡,同时完成了一次脱皂。在脱色过程中,加入活性白土脱色,同时残余的微量皂被活性白土进一步吸附,达到了二次脱皂的效果。考察了碱炼油中含皂量、碱炼油中含水量、养晶时间和活性白土添加量对二次脱皂后脱色油中残皂量的影响。通过单因素试验和响应面优化试验确定玉米油精炼脱皂的最优工艺条件为:碱炼油中含皂量300 mg/kg,碱炼油中含水量0.4%,养晶时间24 h,活性白土添加量0.5%。在最优工艺条件下进行脱皂,得到脱色油中残皂量为0.19 mg/kg,脱皂率为99.9%。新工艺脱皂效果更好,而且不经过水洗过程,无废水排放,符合节能环保的工艺要求,而且简化了加工工艺。     

油脂脱酸过程中碱炼效果优化研究

油脂脱酸处理过程一般采用氢氧化钠溶液进行处理,在去除原料油中游离脂肪酸和磷脂的同时,也会形成产生大量的皂,如果皂不能被有效脱除,会增大油脂后续的加工难度。本文通过对油脂脱酸过程中碱炼的实验条件的研究和优化,确定了在碱反应温度为75℃、碱反应时间为20 min、水洗温度为92℃、水洗水添加量为8%、柠檬酸添加量为0.04%时,可以有效的将脱酸油的含磷量控制在5 mg/kg左右,含皂量控制在30 mg/kg内,为油脂后续的精炼打下良好的基础。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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