冷榨山核桃油的理化性质及氧化稳定性研究

以山核桃仁为原料,通过冷榨机机械压榨,得到冷榨山核桃油,通过化学方法分析其理化指标,用气相色谱法分析其脂肪酸组成,用Rancimat法分析其氧化稳定性和抗氧化剂对其抗氧化效果。结果表明:冷榨山核桃油主要理化指标:酸价1.96 mg KOH/g,过氧化值2.24 mmol/kg,碘值102.84 g I2/100 g,皂化值189.73 mg KOH/g;冷榨山核桃油主要有不饱和脂肪酸组成,不饱和脂肪酸含量占91.83%,其中油酸60.95%,亚油酸26.69%,α-亚麻酸3.11%;建立了lg(诱导期)与Ranciamt氧化诱导温度之间的线性关系;在抗氧化剂添加量相等的情况下,TBHQ的抗氧化效果最好,其次是迷迭香提取物和和茶多酚;使用100 mg/kg TB-HQ+200 mg/kg迷迭香提取物作为冷榨山核桃油的抗氧化剂,可使冷榨山核桃油在120℃的诱导期延长2.88倍。     

水酶法油茶籽油的抗氧化剂筛选

采用Schaal 烘箱加速氧化法对比研究4种抗氧化剂及其浓度对油茶籽毛油氧化稳定性的影响,并利用油脂氧化稳定性分析仪测定4种抗氧化剂及其浓度对油样的氧化诱导期的影响。在此基础上,将添加最佳抗氧化剂的油茶籽毛油与空白组(油茶籽毛油)及市售油茶籽油作对比,进行高温连续加热实验并测定油样过氧化值、酸价、p-茴香胺值。结果表明, 0.2 g/kg添加量的叔丁基对苯二酚(TBHQ)抗氧化效果最佳,诱导期最长,为22.76h, 0.2 g/kg添加量的茶多酚棕榈酸酯的抗氧化效果次之,诱导期为15.65 h,但从抗氧化剂的安全性考虑,最终选择茶多酚棕榈酸酯为最佳抗氧化剂。高温连续加热的结果表明, 0.2 g/kg茶多酚棕榈酸酯的添加可有效提高水酶法制备的油茶籽毛油的品质。     

抗氧化剂在青刺果油贮藏稳定性中的应用研究

以青刺果油为试材,采用Schaal烘箱法,以过氧化值(POV)为指标,研究了4种抗氧化剂(迷迭香提取物、维生素E、茶多酚棕榈酸酯、抗坏血酸棕榈酸酯)、2种增效剂(维生素C、柠檬酸)及其复配后对青刺果油贮藏稳定性的影响,并与TBHQ作对比。结果表明:4种抗氧化剂对青刺果油的抗氧化强弱顺序为迷迭香提取物茶多酚棕榈酸酯抗坏血酸棕榈酸酯维生素E;维生素C、柠檬酸对迷迭香提取物、迷迭香提取物+茶多酚棕榈酸酯的抗氧化性能均有一定的协同增效作用,且柠檬酸的协同效果强于维生素C;单一抗氧化剂迷迭香提取物及其各复配抗氧化剂对青刺果油的抗氧化性能均优于TBHQ;添加0.04%迷迭香提取物+0.02%茶多酚棕榈酸酯+0.02%柠檬酸的青刺果油贮藏稳定性最高,可使青刺果油在25℃条件下的货架期由128 d延长至784 d。     

天然抗氧化剂对亚麻籽甘油二酯油氧化稳定性的影响

为提高亚麻籽甘油二酯油的氧化稳定性,研究了抗坏血酸棕榈酸酯、迷迭香提取物和维生素E及其组合对亚麻籽甘油二酯油的抗氧化作用。以氧化诱导时间为响应值,在单因素实验基础上,通过响应面分析确定最优的抗氧化剂组合。考察了优化的抗氧化剂组合对亚麻籽甘油二酯油高温加热时反式脂肪酸含量的影响。结果表明：相较于单一的维生素E、迷迭香提取物和抗坏血酸棕榈酸酯,三者组合能显著提高亚麻籽甘油二酯油的氧化稳定性;最优抗氧化剂组合为抗坏血酸棕榈酸酯添加量84 mg/kg、迷迭香提取物添加量405 mg/kg、维生素E添加量1 808 mg/kg,在此条件下亚麻籽甘油二酯油的氧化诱导时间为11.13 h,是空白对照的6.79倍;该抗氧化剂组合能抑制油中反式脂肪酸的生成。天然抗氧化剂绿色、安全,可有效提高亚麻籽甘油二酯油的氧化稳定性。     

几种抗氧化剂对棉籽油氧化稳定性的影响

利用Rancimat法研究3种天然抗氧化剂迷迭香提取物、茶多酚、维生素E(VE)及合成抗氧化剂特丁基对苯二酚(TBHQ)对棉籽油抗氧化性能的影响.通过在棉籽油样品中添加不同质量浓度的单一和复合配比的抗氧化剂,分别测定诱导时间并考察抗氧化效果.结果表明,在棉籽油中单一抗氧化剂的抗氧化性能依次为TBHQ＞迷迭香＞茶多酚＞VE;在复合抗氧化剂组合中,迷迭香提取物与茶多酚以3∶1进行复配时具良好的协同增效作用;当3种天然抗氧化剂与TBHQ进行复配时,其抗氧化效果优于同等质量浓度的单一天然抗氧化剂.     

天然抗氧化剂对牡丹籽油氧化稳定性的影响

采用Schaal烘箱法,以合成抗氧化剂二叔丁基羟基甲苯(BHT)为阳性对照,研究茶多酚、迷迭香提取物、生育酚、大豆异黄酮、葡萄籽提取物天然抗氧化剂对牡丹籽油氧化稳定性的影响。结果表明,5种天然抗氧化剂均能提高牡丹籽油的氧化稳定性,但单独使用的效果要差于BHT;0.2 g/kg(以底油质量计,下同)迷迭香提取物+0.2 g/kg生育酚的协同抗氧化效果较接近于BHT;柠檬酸对茶多酚、迷迭香提取物、生育酚均有抗氧化增效作用,其中0.2 g/kg柠檬酸+0.4g/kg迷迭香提取物的抗氧化效果要好于0.2 g/kg的BHT。     

牡丹籽油优势抗氧化剂研究

对牡丹籽油及其他5种植物油的基本理化指标进行了测定比较。牡丹籽油酸值(KOH)(2.034 mg/g)、过氧化值(0.286 mmol/kg)均在国标限值以内,碘值(I)185.8 g/100 g,说明其为干性油,皂化值(KOH)(188.1 mg/g)符合国家规定注射用油标准,较其他5种植物油品质好。选用迷迭香提取物、α-生育酚、TBHQ 3种抗氧化剂,并选择柠檬酸作为抗氧化增效剂,以不同比例组合加入牡丹籽油中,采用Rancimat法测定其氧化诱导时间(OSI)以确定优势抗氧化剂,结合温度外推法推测牡丹籽油货架期。最终遴选0.02%TBHQ+0.01%柠檬酸为优势抗氧化剂,推得20℃下添加此抗氧化剂的牡丹籽油货架期为3 737 h,约是未加抗氧化剂牡丹籽油的27倍,显著提高了牡丹籽油的耐贮藏性。     

迷迭香天然抗氧化剂的应用研究

以核桃油为实验基油,研究了迷迭香天然抗氧化剂的应用。通过抗氧化实验、储藏实验和烹调实验,比较了迷迭香抗氧化剂和TBHQ的抗氧化效果。结果表明,迷迭香抗氧化剂具有较佳的抗氧化效果,在核桃油中随着迷迭香抗氧化剂添加量的增大抗氧化效果依次增强,0.02%迷迭香抗氧化剂与0.02% TBHQ有相似的抗氧化能力,可对核桃油酸败和反式脂肪酸形成起到延缓作用。     

天然复合抗氧化剂对精炼栀子果油抗氧化性影响

目的 比较不同抗氧化剂对精炼栀子果油的抗氧化效果,确定天然复合抗氧化剂复合配方,探究天然复合抗氧化剂在煎炸条件下对精炼栀子果油的保护作用。方法 以精炼栀子果油为原料,比较天然抗氧化剂（葡萄籽提取物、茶多酚、茶多酚棕榈酸酯、抗坏血酸棕榈酸酯、迷迭香提取物）和合成抗氧化剂（dl-α-生育酚、BHT、TBHQ）与精炼栀子果油结合前后的自由基清除能力及对油脂Pf值的影响;通过D-optimal设计分析确定天然复合抗氧化剂复合配方;在160℃条件下,考察添加了TBHQ和天然复合抗氧化剂后精炼栀子果油的过氧化值、羰基价、茴香胺值和主要脂肪酸变化规律。结果 茶多酚棕榈酸酯、抗坏血酸棕榈酸酯、迷迭香提取物与精炼栀子果油结合后能更好的发挥其自由基清除能力,提高油脂Pf值,茶多酚在提高油脂Pf值方面也具有显著效果;天然复合抗氧化剂复合配方为茶多酚0.1 g/Kg+茶多酚棕榈酸酯0.15 g/Kg+抗坏血酸棕榈酸酯0.05 g/Kg+迷迭香提取物0.18 g/Kg;添加天然复合抗氧化剂后对精炼栀子果油的过氧化值、羰基价的抑制效果均好于TBHQ,对茴香胺值抑制效果与TBHQ相当,对多不饱和脂肪酸具有良好的保护效果。结论 天然抗氧化剂在精炼栀子果油中的抗氧化效果良好,添加天然复合抗氧化剂后精炼栀子果油具有很好的氧化稳定性。     

核桃油的理化性质及氧化稳定性研究

以核桃为原料,经冷榨机压榨得到核桃油,用Rancimat法分析其氧化稳定性和天然抗氧化剂对其抗氧化效果。正交试验结果表明:天然抗氧化剂复配最优组合为茶多酚0.40 g/kg、抗坏血酸0.20 g/kg、迷迭香0.15 g/kg、维生素E0.40 g/kg,可使压榨核桃油在120℃的诱导期延长2.33倍。     

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