精炼对大豆油和菜籽油中主要微量成分的影响研究

研究了大豆油和菜籽油中过氧化物、游离脂肪酸、生育酚、甾醇、反式酸、聚甘油酯等微量物质含量随精炼工序的变化。油脂中过氧化值(PV)下降主要在精炼的脱色阶段,本研究中,大豆油PV在脱色阶段下降幅度为63.27%,而菜籽油PV下降幅度为93.07%;脱酸处理后,油脂的酸价(AV)急剧下降,但植物甾醇在这一阶段损失最为严重,且伴随产生缩水甘油酯。生育酚损失主要在脱臭环节,尤以γ-生育酚损失最多。脱臭处理是有害物质反式脂肪酸、聚甘油酯以及缩水甘油酯明显上升的主要环节。     

化学和物理精炼方法对小麦胚芽油品质劣变的影响

为提高精炼的小麦胚芽油品质质量,该文研究了化学和物理精炼过程中小麦胚芽油的品质劣变程度。结果表明:化学精炼的小麦胚芽油,酸价降至0.18 KOH/(mg/g),反式脂肪酸含量由毛油的未检出增加到0.07%,生育酚含量损失了37.14%。物理精炼的小麦胚芽油,在真空残压≤60 Pa,在温度为200℃~240℃,时间为2 h~8 h条件下脱酸,酸价降为5.49 KOH/(mg/g)~0.19 KOH/(mg/g),反式脂肪酸含量为0.10%~3.13%;过氧化值为1.61 mmol/kg~4.33 mmol/kg,茴香胺值13.76~59.3;生育酚含量减少26.68%~85.90%。由其试验结果对比知,化学精炼对小麦胚芽油品质劣变的影响明显小于物理精炼,尤其是防止反式脂肪酸含量增加、维生素E含量损失等方面显著,是一种适合富含高不饱和脂肪酸、维生素E等功能性营养成分类型的油脂的精炼方法。     

生育酚及甾醇含量对大豆油氧化稳定性及贮藏稳定性的影响

植物油是生育酚、甾醇等活性物质的最主要的膳食来源之一,但现有的过度精炼的工艺造成了生育酚和甾醇的大量损失,大大降低了食用植物油的营养价值。随着人们对营养健康的日益关注,加上行业内对植物油适度精炼工艺的号召,需要提高精炼后植物油中生育酚、甾醇的保留量,但植物油中生育酚和甾醇的最低含量的确定缺乏基础研究依据。因此,本文分别利用Rancimat法和Schaal烘箱法比较了不同生育酚及甾醇含量的大豆油的氧化稳定性和贮藏稳定性的差异,结果表明,生育酚和甾醇能够显著提高大豆油贮藏过程中的稳定性,但并不是剂量越高效果越强。当大豆油中生育酚及甾醇分别保留至0.12%、0.35%时,大豆油的氧化稳定性最强;当大豆油中生育酚及甾醇分别保留至0.12%、1.29%时,大豆油的贮藏稳定性最佳。本研究结果为植物油适度精炼工艺中相应产品标准(草案)的制修定提供基础数据,为探究以营养物质含量高低作为植物油新分级指标之一的可行性提供借鉴。     

生育酚及甾醇含量对大豆油氧化稳定性及贮藏稳定性的影响

植物油是生育酚、甾醇等活性物质的最主要的膳食来源之一,但现有的过度精炼的工艺造成了生育酚和甾醇的大量损失,大大降低了食用植物油的营养价值。随着人们对营养健康的日益关注,加上行业内对植物油适度精炼工艺的号召,需要提高精炼后植物油中生育酚、甾醇的保留量,但植物油中生育酚和甾醇的最低含量的确定缺乏基础研究依据。因此,本文分别利用Rancimat法和Schaal烘箱法比较了不同生育酚及甾醇含量的大豆油的氧化稳定性和贮藏稳定性的差异,结果表明,生育酚和甾醇能够显著提高大豆油贮藏过程中的稳定性,但并不是剂量越高效果越强。当大豆油中生育酚及甾醇分别保留至0.12%、0.35%时,大豆油的氧化稳定性最强;当大豆油中生育酚及甾醇分别保留至0.12%、1.29%时,大豆油的贮藏稳定性最佳。本文研究结果为植物油适度精炼工艺中相应产品标准（草案）的制修定提供基础数据,为探究以营养物质含量高低作为植物油新分级指标之一的可行性提供理论支撑。     

精炼对菜籽油品质的影响

菜籽油精炼过程是一个发生物理与化学变化的过程,在这一过程中,菜籽油损失了一些天然的微量物质,也引入或产生了多种其他微量物质,而这些微量物质的变化对菜籽油的品质具有决定性影响.对国内6厂家生产的菜籽油进行取样,选取酸值、过氧化值、磷含量、色泽、生育酚含量、植物甾醇含量、反式酸含量这几类对菜籽油品质影响较大的微量物质,对其进行分析测定,以期得到菜籽油精炼各工序中这些微量物质的变化规律,为菜籽油的适度精炼提供依据.     

我国不同产区核桃油组成成分与氧化稳定性研究

选取我国西南、西北和东部三大产区的 16 种薄皮核桃分别压榨制油,测定核桃油的脂肪酸组成、甘油三酯组成、总酚、生育酚、植物甾醇和氧化稳定性指数。结果表明,不同产区核桃油的脂肪酸组成主要为亚油酸 C18∶2(51.21%~68.97%),油酸 C18∶1(12.56%~26.04%),亚麻酸 C18∶3(6.82%~15.01%)和棕榈酸 C16∶0(3.05%~8.27%),甘油三酯包含三亚酸甘油酯 LLL(27.87%~39.47%)和油酸亚油酸亚麻酸甘油酯 OLLn(17.07%~24.18%)。微量伴随物植物甾醇,生育酚和总酚含量分别为 540~1 594 mg/kg,10~1 303 mg/kg,345~2 579 mg/kg。根据与其他国家和地区的核桃油比较,可以推断出不同的种植区域地理位置和气候的差异,导致了核桃油成分的差异。在此基础上将氧化稳定性指数与脂肪酸组成、微量伴随物含量进行多元线性回归分析后,得出亚油酸,α-生育酚和总酚是影响核桃油氧化稳定性的主要因素。     

精炼对大豆油和菜籽油抗氧化活性的影响

研究了大豆油和菜籽油在精炼过程中酸值、过氧化值、生育酚含量和甾醇含量的变化,以及由此引起的氧化稳定性和抗氧化能力的变化。结果表明:随着精炼的进行,油脂中酸值、过氧化值、生育酚含量及甾醇含量均不断降低;酸值和过氧化值分别在脱酸和脱色阶段急剧下降;生育酚尤其是γ-生育酚和δ-生育酚,主要在脱臭阶段损失,而甾醇在脱酸阶段急剧降低;生育酚和甾醇的不断损失导致油脂的氧化稳定性指数降低,而脱臭后由于游离脂肪酸的进一步除去又有所增强;精炼中微量物质的损失对油脂的自由基清除能力并无显著影响,但油脂的总还原能力在脱酸之后显著降低,这一变化与其中生育酚含量和甾醇含量的变化趋势密切相关。     

7种食用植物油物性及氧化稳定性评价

对国内7种食用植物油的脂肪酸组成、总酚、生育酚、植物甾醇、苯并(a)芘、黄曲霉毒素B1、3-氯丙醇酯含量、氧化稳定性指数(OSI)等指标进行测定分析。结果表明:这7种食用植物油不饱和脂肪酸含量均较高(78.29%~91.92%),但不同油的脂肪酸组成比例各不相同,不饱和脂肪酸、其中单不饱和脂肪酸、多不饱和脂肪酸含量最高的分别为菜籽油(91.92%)、油茶籽油(80.44%)和葵花籽油(61.18%);微量活性成分中,菜籽油的总酚含量最高,为139.83 mg/kg;大豆油、菜籽油、玉米油中γ-生育酚含量较高,葵花籽油、米糠油中α-生育酚含量较高,大豆油生育酚含量最高,为1 129.21 mg/kg;不同油中植物甾醇均以β-谷甾醇为主,米糠油、玉米油中植物甾醇含量较高,分别为10 705.8 mg/kg和8 596.7 mg/kg;危害因子中,只有少数食用植物油检出苯并(a)芘和黄曲霉毒素B1,且含量均符合国家相关标准规定;菜籽油、葵花籽油、大豆油、花生油中3-氯丙醇酯总量较低,均小于1.0 mg/kg;菜籽油、大豆油的氧化稳定性指数(OSI)较高,葵花籽油、油茶籽油的较低,且与总酚含量呈极显著正相关。     

如何提升精炼效益和油脂质量

为了提高食用油的市场竞争力和油脂质量、满足消费者的需求,对精炼厂进行技术改造和维修,采取适度精炼,尽可能多地保存活性物质(如甾醇、维生素E),控制反式酸增量在0.8%以内,控制缩水甘油酯含量(≤50 mg/kg)、3-氯丙醇酯含量(≤2μg/kg),是降低生产成本、辅料消耗,提高油脂质量的必要措施。     

国内外米糠油品质的研究

旨在改善国内市售米糠油品质,选取11种国内外来源的米糠油,对其基本理化性质、脂肪酸及甘油酯组成、生物活性成分及有害物质含量进行测定。结果表明：不同来源的米糠油酸值、过氧化值、色泽等基本理化指标均符合国标限定要求;不同来源米糠油脂肪酸组成差别不大,甘油酯组成差异明显;不同来源米糠油中生物活性成分含量差异较大,谷维素含量在3 200~26 000 mg/kg范围内,植物甾醇含量在224~5 197 mg/kg范围内,生育酚含量在35~400 mg/kg范围内,角鲨烯含量在1~12 mg/kg范围内;不同来源米糠油塑化剂及苯并（a）芘含量均符合国标限定要求,然而国产的米糠油中3-氯丙醇酯及缩水甘油酯含量远超欧盟标准。国内米糠油加工企业应改进生产工艺,减少精炼过程中氯丙醇酯及缩水甘油酯的生成。     

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