烘烤条件对奇亚籽油理化性质及脂肪酸组成的影响

对奇亚籽进行烘烤、压榨取油,测定不同烘烤条件(温度、时间)下奇亚籽油的理化性质及脂肪酸组成,探讨烘烤温度和时间的影响。结果表明:随着烘烤温度的升高和烘烤时间的延长,奇亚籽油色泽加深,酸价、过氧化值、K_(232)、K_(268)均呈现上升趋势,且180℃烘烤50 min以上较其他条件下显著升高(p0.05);烘烤条件对脂肪酸组成无影响。故烘烤奇亚籽不宜在高温下进行,若采用180℃烘烤时,则时间不应超过50 min。     

油茶籽油中苯并[a]芘溯源及其控制技术研究

为了探明油茶籽油中苯并[a]芘的来源,研究了原料来源、干燥方式、烘烤温度与时间、制油方式等因素对油茶籽油中苯并[a]芘含量的影响,考察了油茶籽油在精炼过程从脱胶、脱酸、脱色至脱臭过程中苯并[a]芘含量的变化。结果表明,制油方式、烘烤工艺与油脂精炼是油茶籽油中苯并[a]芘含量的主要影响因素。与压榨法相比,浸提法制得的油茶籽油中苯并[a]芘的含量无显著差异(P0.05)。当温度在90~150℃、时间为0.5~3 h时,随着烘烤温度升高与时间延长,油茶籽油中苯并[a]芘含量持续增加,因此,在保证油茶籽油品质与生产工艺要求的前提下,应尽量缩短烘烤时间并降低烘烤温度。油茶籽油精炼中的脱色能有效脱除油茶籽油中的苯并[a]芘,温度为120℃,用6%的白土脱色20 min,油茶籽油中的苯并[a]芘从脱色前的3.757 0μg/kg降至0.265 4μg/kg,脱除率达到93.08%。     

压榨亚麻籽油中苯并（a）芘含量超标的防控措施研究

针对亚麻籽油产品质检经常出现苯并(a)芘含量超标问题,通过模拟实验研究了炒籽压榨生产亚麻籽油工艺中炒籽温度、炒籽时间对压榨亚麻籽油中苯并(a)芘含量的影响规律和防控措施。结果表明:炒籽温度超过180℃后,炒籽温度越高,压榨亚麻籽油中苯并(a)芘含量越高,且苯并(a)芘含量超过国标限量值(10μg/kg)的炒籽时间越短,说明炒籽温度过高是出现产品苯并(a)芘含量超标的主要原因;热重分析实验发现亚麻籽在172～174℃有热失重速率谷值,超过该温度后,热失重速率快速升高,说明有机物大量裂解从而快速生成苯并(a)芘;结合炒籽实验和热重分析实验,防控苯并(a)芘含量超标的适宜炒籽温度为不高于170℃; 170℃炒籽75 min压榨得到的亚麻籽油苯并(a)芘含量低于食品安全国家标准限值(10μg/kg),可以作为有效防控苯并(a)芘含量超标的技术措施。     

原料预处理对油茶籽油苯并(a)芘含量的影响

研究了油茶籽干燥、蒸炒过程对油茶籽油苯并(a)芘含量的影响。结果表明:烘箱和流化床干燥过程均导致油茶籽油中苯并(a)芘含量增加,相同干燥温度和干燥时间下,流化床干燥产生的苯并(a)芘更多;炒籽过程苯并(a)芘含量显著提高,而蒸坯使得油茶籽油中苯并(a)芘含量较低;压榨饼浸出取油过程容易使苯并(a)芘在油中富集,可能会导致压榨饼浸出油中苯并(a)芘含量超标。     

加工工艺对香榧籽油中挥发性物质组成的影响

旨在为风味香榧籽油的开发提供理论支持,考察了不同加工工艺（烘烤温度和压榨工艺）对香榧籽油理化指标的影响,并采用电子鼻、顶空固相微萃取-气质联用（HS-SPME-GC-MS/MS）等技术研究不同烘烤温度（140、150、160、170、180 ℃）和压榨工艺（螺杆压榨和液压压榨）对香榧籽油中挥发性物质组成的影响。结果表明：烘烤温度和压榨工艺对香榧籽油酸值影响较小,随烘烤温度的升高,螺杆压榨和液压压榨对香榧籽油过氧化值的影响不同,但不同烘烤温度和压榨工艺条件下制取的香榧籽油酸值和过氧化值均符合GB 2716—2018中的要求;电子鼻分析表明氮氧化合物、硫化物、芳香成分、甲基类物质对香榧籽油风味的影响较大;液压压榨和螺杆压榨香榧籽油风味最浓郁的烘烤温度分别为140 ℃和170 ℃;香榧籽油中共检出挥发性物质7类42种,其中萜烯类物质占主导;不同温度烘烤后液压压榨制取的香榧籽油中共有5种挥发性物质的相对含量发生显著变化,而螺杆压榨制取的香榧籽油中有18种挥发性物质的相对含量发生显著变化,柏木脑和香芹酮为两种压榨工艺共有的相对含量发生显著变化的物质。综上,压榨工艺会影响香榧籽油达到浓郁风味所需要的热风烘烤条件,且螺杆压榨相较于液压压榨,其风味物质种类变化更加丰富。     

油茶籽油精炼过程中苯并[a]芘风险控制技术研究

研究了油茶籽油加工过程中苯并[a]芘风险控制技术。本文以传统生产工艺的压榨原油、脱色油、成品油和浸提毛油为研究对象,除压力外,模拟油茶籽油加工过程中的精炼工艺流程工况,设计了苯并[a]芘风险控制技术实施方案,并用苯并[a]芘残留量作为评价指标。结果表明：4种试验油均不同程度地存在苯并[a]芘,尤以压榨原油含量最高。常规脱色工艺不致油茶籽油中苯并[a]芘含量增加,而高温脱臭工艺则会使油茶籽油中苯并[a]芘含量显著增加。脱色工艺中用传统的5%活性白土与0.5%硅藻土分别处理均不能去除苯并[a]芘。用1%活性炭与助滤剂硅藻土配伍去除苯并[a]芘效果最好。     

不同压榨温度下奇亚籽油气味组分的电子鼻分析

以奇亚籽为原料,采用压榨法制取奇亚籽油,考察不同的压榨温度（60~120 ℃）对奇亚籽出油率和奇亚籽油酸值的影响,利用电子鼻对奇亚籽油气味组分进行分析。结果表明：高温对奇亚籽出油率和奇亚籽油酸值有一定程度影响;主成分分析表明,第1主成分和第2主成分总体贡献率为99.91%,可以区分60 ℃、70~100 ℃和110~120 ℃下压榨的奇亚籽油;传感器贡献率分析表明,奇亚籽油的气味组分主要有无机硫化物、甲烷等短链烷烃、氮氧化合物、芳香成分、苯类等,70~100 ℃范围内的油样与60 ℃条件下油样对W2S传感器有不同响应,110~120 ℃范围内的油样与 60 ℃ 条件下油样对W2S和W2W传感器有不同响应;线性判别分析结果表明,80 ℃与90 ℃油样、110 ℃与120 ℃油样气味组分具有一定相似性,与其他压榨温度下油样的气味组分差异度较大。利用电子鼻可以将60 ℃与其他压榨温度下的奇亚籽油进行区分。     

响应面优化超声波辅助提取经烘烤预处理奇亚籽油工艺的研究

以奇亚籽为原料,采用超声波辅助提取奇亚籽油。通过单因素设计实验研究溶剂种类、料液比、超声时间、烘烤温度、烘烤时间对奇亚籽出油率的影响。在单因素实验基础上通过响应面法优化了超声波辅助提取经烘烤预处理奇亚籽油脂的最佳工艺条件。结果表明,超声波提取奇亚籽油脂的最佳工艺条件为烘烤温度160℃,烘烤时间46 min,料液比1∶17,超声时间55 min。在最优工艺条件下,奇亚籽的出油率为(39.41±0.72)%。奇亚籽油中不饱和脂肪酸含量丰富,其中亚麻酸(C18∶3n3)质量分数最高为62.90%,亚油酸(C18∶2n6c)质量分数为18.25%。     

卷烟主流烟气中苯并[a]芘分离纯化条件的研究

在JDumont方法的基础上,将其正相NH2Sep-Pak柱替换成商品化的固相萃取小柱,优化了超声提取时间,系统讨论了卷烟总粒相物提取液的酸碱洗涤,固相萃取洗脱流速,以及乙腈反萃取等操作对卷烟主流烟气中苯并[a]芘的分离纯化效果的影响。并利用改进的实验条件,测定了卷烟主流烟气中苯并[a]芘的含量。实验结果表明,苯并[a]芘的分离效果明显改善,测定值与国内报道一致。     

超临界CO_2萃取奇亚籽油工艺优化及抗氧化活性的研究

为高效地提取奇亚籽油,采用单因素及正交实验优化超临界CO_2萃取奇亚籽油最佳工艺条件,考察物料粒度、萃取压力、萃取温度以及萃取时间4个因素对奇亚籽油萃取率的影响,并对奇亚籽油进行抗氧化活性的测定。结果表明:超临界CO_2萃取奇亚籽油最佳工艺条件为物料粒度60目、萃取压力25 MPa、萃取温度50℃、萃取时间2.5 h,奇亚籽油萃取率为85.50%。奇亚籽油中富含不饱和脂肪酸,占总脂肪酸的88.22%,其中亚麻酸高达69.86%。抗氧化实验表明,奇亚籽油对DPPH自由基和ABTS~+自由基具有较强的清除作用,对超氧阴离子自由基也显示出一定清除效果。     

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