微波-超声协同辅助提取燕麦麸油的研究

本研究采用微波-超声协同辅助提取技术从燕麦麸皮中提取燕麦麸油,考察了溶剂配比、微波功率、液料比和作用时间对燕麦麸油得率和抗氧化活性的影响。试验结果表明,燕麦麸油的最佳微波-超声协同辅助提取工艺条件为正己烷∶乙醇=1∶1(V/V)、功率300 W、液料比12∶1(m L/g)、作用时间60 s,在此条件下,燕麦麸油的得率为6.88%;与溶剂浸提相比,微波-超声协同辅助提取的燕麦麸油具有更强的抗氧化活性,对DPPH自由基清除的IC50值1.064 mg/m L,其中主要的抗氧化活性物质总酚、生育酚(VE)、甾醇的含量分别为(1 531.04±10.28)、(84.15±2.47)mg/kg和(578.23±7.04)mg/100 g;GCMS结果显示微波-超声协同辅助提取燕麦麸油的主要脂肪酸组成为棕榈酸、油酸、亚油酸,与溶剂浸提的无明显差异。     

燕麦麸油提取工艺及功能特性的研究进展

从燕麦中提取燕麦麸油的工艺有超声波辅助提取、超声波-微波协同提取、超临界CO2萃取法和复合溶剂浸提法。燕麦麸油含有质量较优的脂肪酸,其中棕榈酸、油酸和亚油酸占燕麦麸油总脂肪酸含量的95%以上,此外燕麦麸油中还有较多的燕麦蒽酰胺、甾醇、维生素E、植酸、酚类等抗氧化活性类的物质,这些物质具备抑制低密度蛋白氧化、促使活性氧清除等功效。由于具备这些独特理化功效特性,使得燕麦麸油在食品行业、药用中、高级护肤品中显示出巨大的应用潜力。     

番木瓜籽油的营养特性及稳定性

以番木瓜籽为研究对象,采用溶剂提取法提取番木瓜籽油,运用GC-MS对番木瓜籽油脂肪酸组成进行分析,对其理化性质和脂溶性伴随物含量进行检测,并对其抗氧化活性及稳定性进行研究。结果表明:以正己烷为提取溶剂,番木瓜籽油得率为(28.62±0.27)%;番木瓜籽油富含不饱和脂肪酸(86.54%),主要是油酸((44.03±1.21)%)和亚油酸((42.25±1.32)%),脂溶性伴随物主要有β-谷甾醇((5.11±0.16) mg/kg)、菜油甾醇((0.33±0.02) mg/kg)、生育酚((150.41±3.13) mg/kg);此外,番木瓜籽油酸值(KOH)((1.25±0.15) mg/g)、过氧化值((0.25±0.04)mmol/kg)均符合GB 2716—2018要求;番木瓜籽油对DPPH自由基和羟自由基均有较好的清除效果,IC50值分别为9.21 mg/m L和0.53 mg/m L,同时还具有较好的储藏稳定性和热加工稳定性。番木瓜籽可作为一种潜在的油料资源。     

莲藕多酚浸提工艺优化及其抗氧化活性研究

采用匀浆法浸提莲藕中的多酚,以多酚提取得率和提取液DPPH自由基清除率为指标分别优化浸提工艺参数,并比较分析提取液的酚类物质组成及抗氧化活性。结果表明:以多酚提取得率为指标的优化工艺A参数为酸醇比2278(VV)、均质时间6.8 min和均质转速10 500r/min;而以提取液DPPH自由基清除率为指标优化所得工艺B参数为酸醇比1981(VV)、均质时间8.6 min和均质转速9 100r/min;各因素对多酚提取得率和DPPH自由基清除率的影响均为酸醇比均质时间均质转速;工艺A的多酚提取得率(165.85 mg GAE/100g·FW)显著高于工艺B(P0.05),其DPPH自由基清除IC50值分别为4.75,6.83μg GAE/mL。工艺A较适用于莲藕抗氧化活性多酚的提取制备。     

超声波强化提取油茶籽油的研究

油荼籽油中不饱和脂肪酸含量丰富,是一种功能性油脂.研究了提取溶剂、液料比、提取时间对超声提取油茶籽油和加热浸提油茶籽油的影响.结果表明,正己烷是较理想的溶剂;适当增加溶剂量、提取时间、超声波功率、提取温度,油荼籽油得率随之增加;在温度40℃、液料比(V/m)6:1、提取时间30 min和超声波功率300 W的条件下进行超声提取,油茶籽油得率为45.23%;对加热浸提来说,在温度60℃、液料比(V/m)7:1、提取时间90 min条件下.油茶籽油得率仅为38.15%.由此可见,超声作用明显降低了提取温度、减少了溶剂用量、缩短了提取时间,而且使油茶籽油得率提高.     

马蔺籽油的索氏提取工艺、成分分析及抗氧化活性研究

以石油醚为提取溶剂,选取提取时间、提取温度、料液比作为考察因素,在单因素实验的基础上,以马蔺籽油得率为响应值,进行响应面优化实验以确定马蔺籽油最佳提取工艺条件。对马蔺籽油的理化性质、脂肪酸组成及不皂化物成分进行分析,同时研究了马蔺籽油的抗氧化活性。结果表明,马蔺籽油索氏提取最佳工艺条件为提取时间6 h、提取温度70 ℃、料液比1∶ 26。在最佳条件下,马蔺籽油得率达到11.20%。马蔺籽油在265 nm处的吸光度为4.667,呈现黄色透明状。马蔺籽油不皂化物含量1.37%,皂化值(KOH)185.2 mg/g,酸价（KOH）0.038 mg/g,碘值（I）113.7 g/100 g,过氧化值5.159 mmol/kg。GC-MS分析结果显示,马蔺籽油不饱和脂肪酸含量为8471%,脂肪酸组成主要为亚油酸（45.32%）、油酸（38.42%）、棕榈酸（6.88%）及硬脂酸（238%）。不皂化物中甾醇类化合物总含量高达66.19%,其中β-谷甾醇725.87 mg/kg、菜油甾醇410.50 mg/kg、豆甾醇1 231.55 mg/kg,另外还含有高浓度的抗氧化剂豆甾-5,24(28)-二烯-3β-醇。马蔺籽油具有良好的抗氧化活性,DPPH自由基清除率IC50值为19.86 mg/mL,FRAP法测定其在质量浓度为280 mg/mL时总抗氧化能力为0.202 4 mmol/L。     

油瓜种仁油提取工艺及理化成分分析

以油瓜种仁为原料,采用单因素实验研究不同提取剂、提取时间、提取温度、料液比对油瓜种仁油得率的影响,并进行正交实验。结果表明:最佳提取条件为正己烷作提取剂、提取时间190min、提取温度90℃、料液比1∶80,在此条件下,油瓜种仁油得率为60.02%。所提油瓜种仁油相对密度0.90±0.05,酸值(KOH)(11.21±0.13)mg/g;钾、锌、铁、锰、镁、钙、铜含量分别为940、11.5、22.1、0.262、124、504、0.286 mg/kg,磷、钠含量分别为0.189%、0.106%,铅含量为0.042 mg/kg,未检测出黄曲霉毒素B1。油瓜种仁油由9种脂肪酸组成,以亚油酸(45.96%)、棕榈酸(29.90%)、油酸(14.16%)和硬脂酸(8.48%)为主,单不饱和脂肪酸(MUFA)含量与多不饱和脂肪酸(PUFA)、饱和脂肪酸(SFA)含量的比为1∶3.3∶2.7,n-6 PUFAs含量与n-3 PUFAs含量的比为63∶1。     

桂花总黄酮提取及其体外抗氧化性能研究

以提取桂花香料后桂花残渣为原料,利用乙醇为溶剂提取桂花残渣中总黄酮类物质,以提高桂花资源利用效率。通过单因素实验和正交试验确定桂花总黄酮最佳提取工艺条件并对桂花总黄酮体外抗氧化性能进行系统评价。实验结果表明,以乙醇为溶剂提取桂花残渣中总黄酮最佳工艺条件为:乙醇浓度50%,提取温度60℃,料液比1∶80,浸提时间2 h,总黄酮得率可达21.54%;体外抗氧化性能研究结果表明,桂花总黄酮具备较好抗氧化活性,添加桂花总黄酮后,亚油酸氧化进程受到明显抑制。     

青冈栎果壳多酚超声波辅助提取工艺优化及体外抗氧化能力研究

采用超声波辅助法提取青冈栎果壳多酚,考察乙醇体积分数、料液比、提取时间、提取次数对多酚得率的影响,并对其最佳提取工艺条件进行优化;以铁还原能力和氧自由基吸收能力为指标,评估青冈栎果壳提取物的体外抗氧化活性。结果表明:青冈栎果壳多酚的最佳提取条件为乙醇体积分数50%、提取时间25 min、料液比140(g/mL)、提取次数5次,此条件下的多酚得率为3.13%。青冈栎果壳提取物具有较强的体外抗氧化能力,其铁还原能力为(984.44±123.15)mg FeSO_4/g·DW,氧自由基吸收能力为(200.15±23.24)mg Trolox/g·DW,均高于商用抗氧化剂BHT,表明青冈栎果壳可作为天然抗氧化剂资源。     

栀子果油的生物活性成分及抗氧化活性评价

以正己烷、乙酸乙酯、乙醇3种溶剂并结合超声辅助提取栀子果油,对所获得的3种粗油和乙醇提取的副产物的得率、油脂组成、生物活性成分以及自由基清除能力进行分析。在固液比(1:8)、温度(40℃)、时间(20 min)、超声强度(200 W)的条件下,乙醇提取得油率为13.26%,略低于正己烷14.86%和乙酸乙酯13.84%,副产物乙醇胶体相是乙醇提油后4℃静置分层得到的,得率为9.68%。乙醇提取栀子果油相中总生育酚含量为1.62μg/mg,是正己烷提取粗油的1.27倍;总甾醇含量为22.63μg/mg,是乙酸乙酯提取粗油的1.29倍。挥发性香草酸、丁香酸、丁香醇为乙醇提取粗油中的主要芳香成分。副产物醇溶性胶体相中检出了γ-亚麻酸(1.50%)和反式亚油酸(1.14%),而在粗油中并未检出;醇溶性胶体相DPPH、ABTS清除率的IC50值分别为0.61mg/m L和0.40 mg/mL,极显著小于粗油中的检验结果(7.60~10.3 mg/mL);通过UPLC-Triple-TOF/MS在醇溶性胶体相中初步鉴定出西红花酸及8种带糖衍生物。实验证明,用乙醇提取栀子果油气味芳香,Omega-6型油脂种类及含量丰富,生育酚、甾醇等活性物质含量更高,此外副产物中的西红花及其衍生物有很强的自由基清除能力,因此具有更高的经济价值。     

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.     

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.     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.