水酶法提取米糠油的试验研究（网络首发、推荐阅读）

水酶法提取油脂工艺的技术关键是酶解及乳状液破乳。研究水酶法提取米糠油工艺,结果表明,膨化米糠粉碎过40目筛,按1∶7.5（w/v）料液比加入超纯水,pH值9.0、57 ℃添加2%的碱性蛋白酶（Alcalase 2.4 L）酶解150 min,离心后调节乳状液pH值至7.0,60 ℃下搅拌60 min破乳,此工艺可获得84.1%以上米糠提油率;水酶法提取米糠毛油的品质特别是生物活性物质的含量,明显优于传统溶剂法提取米糠毛油;糖酶无法提高挤压米糠的提油率,碱性条件更利于米糠油脂提取;碱性条件及CaCl2处理,无助于水酶法提取米糠油乳状液的破乳;20%~30%乙醇处理,可提高乳状液的破乳率。研究创制的水酶法提取米糠油工艺,可促进水酶法制油工艺在植物油脂行业的推广与应用,实现米糠高值化利用。     

生物酶法提取葡萄籽油的工艺研究

生物酶法提取植物油脂是一种新型的油脂加工方法，它既可提高油脂的提取率，又可获得品质较优的植物油脂。以葡萄籽为原料分别加入纤维素酶和中性蛋白酶进行酶解，通过试验分别得出两种酶提取葡萄籽油的最佳工艺参数：纤维素酶提取葡萄籽油的最佳工艺参数为：酶解温度为45℃、酶解时间为1．5h、酶解pH值为4．5、酶用量为3000U／g葡萄籽，油脂提取率为84．1％；中性蛋白酶提取葡萄籽油的最佳工艺参数为：酶解温度为55℃、酶解时间为2．0h、酶用量为2000U／g葡萄籽，油脂提取率为80．3％。对两种酶解提油工艺进行比较可知：中性蛋白酶提油工艺所需成本较低，提取率较高，适合于葡萄籽油的提取。     

酶解三相分离法提取米糠油的研究

本文提出酶解预处理方法,以提高三相分离法从稳定化米糠提取米糠油的提油率。对纤维素酶、中性蛋白酶和木瓜蛋白酶三种酶的试验结果显示,中性蛋白酶对米糠提油率的影响最明显,能使提油率从74.65%提高到93.39%。以提油率为指标,对中性蛋白酶的酶解参数进行考察,各参数影响程度依次为温度>pH值>酶用量>反应时间。最佳酶解温度为50℃,最佳pH值为6.5。     

水酶法同时提取核桃仁油脂及水解蛋白的工艺研究

本试验主要研究了水酶法提取核桃油的酶解工艺。试验首先对α-淀粉酶、中性蛋白酶、以及淀粉酶与中性蛋白酶组成的复合酶的酶解效果进行了比较,确定中性蛋白酶的酶解效果最佳。在确定中性蛋白酶的作用下,研究了酶解温度、pH、酶的添加量、固液比对油脂提取率的影响。最后通过正交试验得出水酶法提取核桃油脂的最佳工艺条件为:酶解温度60℃,蛋白酶添加量为1.5%(m/m),酶解pH为6.0,料液比1∶4,核桃的油脂提取率可达到34.0%,各因素对油脂提取率的影响主次顺序为:固液比酶解pH酶解温度酶的添加量。在油脂提取的最佳工艺条件下,核桃水解蛋白的提取率可达12.37%。     

酶法提取黑加仑籽油

对于酶法提取黑加仑籽油进行了初步探讨。经对比实验筛选出从黑加仑籽中提油的3种酶:复合纤维素酶、果胶酶和中性蛋白酶。通过正交实验分别对3种酶的酶解条件进行优化,得到的结果为,果胶酶:添加量0.5%,pH 6,酶解时间4 h,料液比1∶5,酶解温度50℃,在此条件下提油率为8.03%;复合纤维素酶:添加量1.5%,pH 6,酶解时间4 h,料液比1∶6,酶解温度55℃,在此条件下提油率为10.73%;中性蛋白酶:添加量1.0%,pH 8,酶解时间5 h,料液比1∶5,酶解温度45℃,在此条件下提油率为11.43%。将3种酶复合使用后提油率达到13.89%,显示复合酶法的提取效果要好于单一酶法。     

水酶法提取美藤果粕油脂的工艺研究

美藤果油是2013年新批准的新资源食品,美藤果经低温压榨后提取的油脂质量较高,但同样残油率也较高。为进一步提高油脂利用率,采用水酶法对低温压榨提油后的美藤果粕进行再次提油,考察酶种类、料液比、酶浓度和酶解时间对美藤果粕油脂提取的影响。在单因素实验的基础上,进行正交优化实验并得出最佳工艺条件:料液比(w:w)为1:6,加入p H为7.5的柠檬酸缓冲溶液,添加中性蛋白酶400 U/g,50℃下酶解50 min。在此最佳条件下,油脂提取率高达77%。水酶法提油,条件温和成本低,果粕中的蛋白质还能继续提取利用。     

水酶法提取南瓜籽油过程中乳状液酶法联合化学法破乳工艺研究

为提高水酶法提取南瓜籽油的提油率,采用地衣芽孢杆菌碱性蛋白酶并联合化学破乳法对水酶法提取南瓜籽油过程中产生的乳状液进行破乳研究。通过单素试验并结合响应曲面优化试验,得出酶法破乳的最佳工艺为:液料比0.9:1.0(mL/g)、酶添加量3 078U/g、pH 10.4、酶解温度51℃、酶解时间2.5h,验证实验得破乳率为88.39%。酶解破乳后调节pH对乳状液稳定性及破乳率影响的研究发现当酶解破乳后调节pH至4.5时,破乳率增至95.47%。     

超声辅助二次酶解对大豆乳状液破乳工艺研究

在超声辅助作用下,采用磷脂酶A_1对碱性蛋白酶Alcalase 2.4L酶解膨化大豆制备大豆油过程中产生的乳状液进行二次酶解破乳。在单因素试验基础上,采用响应面分析法对超声辅助二次酶解破乳工艺条件进行优化,确定最优破乳工艺条件为:加酶量1 530 U/g,乳水体积比1∶2.17,反应时间63 min,超声功率204 W。在最优工艺条件下,破乳率为91.14%,总提油率为88.48%。     

超声波辅助水酶法提取胡麻油工艺条件的研究

以胡麻籽为原料,研究了超声波辅助水酶法提取胡麻油的工艺条件。研究结果表明:最佳复合酶为酸性蛋白酶和纤维素酶(2∶1),最佳酶解条件为加酶量0.20 g(20 g底物)、酶解pH值5.0、酶解温度50℃、酶解时间1 h,在此条件下提油率为75.1%;当在超声温度45℃、超声频率45 kHz下处理15 min提油率可升到81.1%。     

复合酶法提取菜籽油工艺优化

为提高菜籽油的得率,探讨应用复合酶法提取菜籽油的最佳工艺条件。以挤压处理后的油菜籽为原料,提油率为考察指标,对复合酶种类和配比进行筛选后,在单因素试验基础上,通过响应面优化试验得出最佳酶解条件。结果表明：以中性蛋白酶、果胶酶和α-淀粉酶为复合酶组成,其配比为0.573:0.315:0.112;酶解最佳工艺条件为：酶解温度50 ℃、酶解时间4 h、酶解pH 6、料液比1:4、复合酶添加量2%,在此条件下油菜籽清油的提油率可达92.333%。     

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