响应面法优化黑加仑籽油中γ-亚麻酸富集工艺

采用响应面优化尿素包合法富集黑加仑籽油中γ-亚麻酸的最佳工艺。在单因素试验基础上,选择包合温度、尿素/混合脂肪酸配比、95%乙醇/尿素配比(mL/g)、包合时间为考察因素,进行四因素三水平的Box-Behnken中心组合设计,采用响应面法分析4个因素对籽油中γ-亚麻酸含量的影响。结果表明,尿素包合法富集黑加仑籽油中γ-亚麻酸的最佳工艺为包合温度-20℃、尿素/混合脂肪酸配比3.5∶1、95%乙醇/尿素配比2.5∶1(mL/g)、包合时间21h,在此条件下,包合后籽油中γ-亚麻酸含量平均值为24.27%。     

尿素包合法富集沙棘果油棕榈油酸的工艺优化

以沙棘果油为原料,采用尿素包合法富集沙棘果油中的棕榈油酸,以棕榈油酸含量为评价指标,采用单因素试验分别考察包合时间、包合温度、醇脲比及脲脂比对棕榈油酸含量的影响,利用响应面软件优化尿素包合法富集沙棘果油中棕榈油酸的工艺。得到的尿素包合法富集沙棘果油中棕榈油酸最佳工艺参数为:脲脂比2.5∶1,包合温度-4℃,包合时间12 h,醇脲比5∶1。在最佳条件下,可将沙棘果油棕榈油酸含量由30.28%提高到54.80%,棕榈油酸回收率为32.46%。     

尿素包合法富集苦瓜籽油中α-桐酸的工艺优化北大核心CSCD

以超临界CO;萃取的苦瓜籽油为原料,经皂化酸解法制得混合脂肪酸,再采用尿素包合法富集其中的α-桐酸。在单因素试验的基础上,采用正交试验对富集工艺条件进行优化。结果表明,α-桐酸的最佳富集工艺条件为:采用95%乙醇作为尿素溶剂,混合脂肪酸与尿素质量比1∶3,尿素与95%乙醇质量比1∶5,包合温度4℃,包合时间24 h。在最佳工艺条件下,α-桐酸纯度从苦瓜籽油中的28.83%提高至60.03%,产物中共轭亚麻酸相对含量达到71.28%。     

低温结晶法纯化元宝枫籽油中神经酸

为了提高从元宝枫籽油中富集神经酸的纯度和收率,将元宝枫籽油皂化制备混合脂肪酸,然后用不同溶剂溶解混合脂肪酸并进行低温结晶,优化结晶溶剂、料液比和结晶时间等工艺参数。结果表明,当元宝枫籽油混合脂肪酸与乙醇以质量体积比1∶ 3混合,在-40 ℃下低温结晶4 h后,得到的结晶中神经酸含量为13.11%,收率为65.48%,终产品中神经酸含量比元宝枫籽油中原有神经酸含量提高了1倍多。     

尿素包合法分离油用牡丹籽油的不饱和脂肪酸工艺优化研究

采用正交实验设计对尿素包合法富集牡丹籽油不饱和脂肪酸工艺进行优化。考察了包合反应中尿素与乙醇质量体积比、包合温度、包合时间对产品中α-亚麻酸含量的影响。结果表明:最佳工艺条件为尿素与95%乙醇质量体积比3∶9、包合温度0℃、包合时间15 h,尿素包合后α-亚麻酸含量达64.95%。尿素包合法可有效地富集牡丹籽油中的不饱和脂肪酸,并且可以提高α-亚麻酸的含量。     

辣木籽油的提取及其中神经酸的纯化工艺研究

为促进辣木籽油中神经酸的开发利用，以辣木籽为原料，采用低温压榨法、超临界CO₂萃取法、索氏抽提法提取辣木籽油，筛选合适的提油方法，再以辣木籽油为原料制备混合脂肪酸，通过低温结晶法纯化辣木籽油中的神经酸，通过单因素实验和响应面实验优化神经酸的纯化工艺。结果表明：低温压榨法提取的辣木籽原油中神经酸含量较高，达到0.88%;低温结晶法纯化辣木籽油中神经酸的最优工艺条件为料液比(混合脂肪酸与结晶溶剂质量体积比)1∶4.2、结晶温度-21℃、结晶时间2.3 h,该条件下所得产品中神经酸含量为(5.36±0.01)%,相比辣木籽原油中神经酸含量提升了5.1倍。通过低温压榨法提取辣木籽油，再采用低温结晶法纯化神经酸，能够获得神经酸含量较高的产品。     

尿素包合法富集驼峰油中不饱和脂肪酸的工艺优化

以精炼驼峰油混合脂肪酸(饱和脂肪酸54. 024 3%,单不饱和脂肪酸34. 645 7%,多不饱和脂肪酸4. 645 3%)为原料,在单因素试验基础上,采用响应面法优化尿素包合法富集其不饱和脂肪酸工艺。结果表明:尿素包合法富集驼峰油中不饱和脂肪酸的最佳工艺条件为尿素质量与95%乙醇体积比3∶8、尿素与混合脂肪酸质量比3. 315∶1、包合温度-2. 37℃、包合时间18. 13 h,在此条件下产物碘值(I)为125. 73 g/100 g,产物中饱和脂肪酸含量为7. 802 5%,单不饱和脂肪酸含量为58. 175 6%,多不饱和脂肪酸含量为17. 322 2%。包合后产物为淡黄色黏稠液态,不饱和脂肪酸含量约为75%。     

响应面法优化尿素包合油茶籽油中油酸工艺研究

利用响应面法优化尿素包合富集油茶籽油中油酸的工艺,以油酸含量、油酸回收率为响应值,研究了m(尿素)∶m(混合脂肪酸)、结晶温度、结晶时间对响应值的影响。结果表明:在m(尿素)∶m(混合脂肪酸)为1.6∶1,结晶温度-3.0℃,结晶时间11.3 h的优化条件下,经1次包合,油酸含量可达92.9%,油酸回收率为39.0%。     

热盐水法提取文冠果油及其脂肪酸分析

以文冠果籽为原料,利用热盐水法提取文冠果籽油。通过响应面法优化提取工艺,建立影响文冠果油提取率的因素与响应值之间的数学模型,并采用GC-MS分析其脂肪酸组成。结果表明:当搅拌转速40 r/min,NaCl加入量10%,料液比1∶3.5(g∶mL)时,油脂提取率可达70.06%,与模型高度拟合;GC-MS分析确定文冠果中主要含8种脂肪酸,其中必需脂肪酸亚油酸含量高达42.83%。     

元宝枫油中神经酸乙酯的分离提纯

将元宝枫油制成混合脂肪酸乙酯,分别利用多级分子蒸馏提纯和分子蒸馏与尿素包合法相结合提纯神经酸乙酯得到高含量的神经酸乙酯产品。六级分子蒸馏直接提纯神经酸乙酯,得到神经酸乙酯含量为78.35%的产品。二级分子蒸馏与尿素包合法相结合时,分子蒸馏脱除甾醇、维生素E、C16、C18、C20及部分C22脂肪酸乙酯,得到神经酸乙酯与芥酸乙酯比例为1∶1的初级产品,再在m(脂肪酸乙酯)∶m(尿素)∶V(甲醇)为1∶5∶35、包合温度35℃、包合时间8 h条件下,经过二次尿素包合处理,可得到神经酸乙酯含量为66.21%的产品。     

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.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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