花椒风味油的制取及品质研究

以花椒果皮为原料,采用大豆油热浸法制取花椒风味油。以花椒风味油的酸价、过氧化值和感官评分为考察指标,通过单因素实验和正交实验优化制取工艺条件。采用顶空固相微萃取-气相色谱-质谱联用技术对花椒风味油和大豆油中挥发性风味成分进行测定。结果表明:制取花椒风味油的最佳工艺条件为浸提温度95℃、浸提时间20 min、花椒果皮添加量15%,在此条件下制取的花椒风味油香气浓郁、麻味足、色泽好且感官评分最高,其酸价(KOH)为0. 40 mg/g,过氧化值为5. 07 mmol/kg,感官评分为9. 1。花椒风味油中维生素E总量为1 869. 86 mg/kg,远高于大豆油中的742. 07 mg/kg;甾醇含量相较于大豆油几乎不变;脂肪酸组成与大豆油的基本相同;花椒风味油中共鉴定出9类83种挥发性风味成分,大豆油中共鉴定出8类25种挥发性风味成分,花椒风味油中挥发性风味成分主要是烯烃类和醇类(相对含量86. 99%),大豆油中主要是烯烃类和醛类(相对含量87. 26%);花椒风味油中醇类18种,占总量的40. 97%,大豆油中醇类仅1种,占总量的1. 74%;花椒风味油中醛类物质含量仅为1. 91%,而大豆油中醛类物质含量为12. 69%。     

花椒籽油与花椒油风味及综合品质对比分析

以新鲜花椒籽为原料,分别采用压榨法和浸出法得花椒籽毛油,对毛油进行精炼得花椒籽精炼油,检测花椒籽油中挥发性风味成分、酸价、过氧化值、酰胺类化合物含量及感官评价,并与8 个市售花椒油的品质进行对比。结果表明：新鲜花椒籽压榨和浸出毛油酸价（以KOH计）分别为5.94、7.37 mg/g,过氧化值分别为1.13、0.59 mmol/kg,明显优于贮存不当的花椒籽所制取的毛油,精炼花椒籽油的酸价和过氧化值均达到GB/T 22479—2008《花椒籽油》中一级油指标要求;花椒籽油中酰胺类化合物含量为7.82～9.80 mg/g,达到并明显优于DBS 51/008—2019《花椒油》中对应指标大于等于2.0 mg/g的要求,也在8 个市售花椒油酰胺类化合物含量7.92～19.11 mg/g范围之内;花椒籽油和花椒油中挥发性风味成分含量最高的均为烯烃类化合物,其次为醇类;2 种油脂的感官评价均呈现明显的麻味和辛辣味。新鲜压榨花椒籽油与作为风味油或调味油的商品花椒油相比,无论是在反映花椒油特征的酰胺类化合物含量和挥发性风味成分含量方面,还是感官评价方面均具有高度相似性和一致性。新鲜花椒籽压榨油香味浓郁、麻味强烈,可以作为优良的花椒籽风味油开发应用,这对实现花椒籽高值化加工利用有重要意义。     

榛子仁提取油脂的营养成分分析

为分析榛子仁油的理化性质、脂溶性维生素E含量及脂肪酸的组成,以榛子仁油为材料,采用冷溶剂指示剂滴定法、自动滴定分析法、正相高效液相色谱法,测定酸价、过氧化值、脂溶性维生素含量等指标。结果表明,榛子仁油酸价1.2 mg/g,过氧化值0.04 g/100 g,碘值90.33 g/100 g,皂化值198.67 mg/g,色泽、透光性良好;α-生育酚含量32 420.16 μg/100 g,生物活性较强;维生素E含量39 392.88 μg/100 g,抗氧化能力较好;含有不饱和脂肪酸92.13%;分别在120、150、180、210℃煎炸10 min～20 min后,棕榈烯酸、棕榈酸等7类脂肪酸均未表现出明显差异,热稳定性良好。     

以稻米油为基油的煎炸调和油品质研究

以稻米油、棕榈油(24℃)和棉籽油为原料调配以稻米油为基油的煎炸调和油,并对其品质进行研究。通过对调和油脂肪酸组成和氧化稳定性的检测,确定稻米调和油配方。在土豆条连续煎炸试验中,对比稻米油和稻米调和油在煎炸过程中理化指标(酸价、过氧化值、碘值、极性组分含量)和营养物质(脂肪酸组成及维生素E、植物甾醇、谷维素含量)变化,综合评估其煎炸性能。结果表明:稻米油含量低于70%的调和油多不饱和脂肪酸含量不超过30%,氧化诱导时间最长的是稻米油含量为60%的调和油(配方2),其次为稻米油含量为50%的调和油(配方1);稻米油、调和油(配方1、配方2)在煎炸30 h后,酸价(KOH)分别增加了1.01、1.21、1.19 mg/g;与配方1相比,配方2的过氧化值初始值(1.78 g/100 g)和峰值(7.48 g/100 g)较小;煎炸30 h,稻米油的碘值(I)从101.66 g/100 g降低到90.57 g/100 g,降幅为10.91%,配方1的碘值(I)从80.23 g/100 g降低到76.34 g/100 g,降幅为4.85%,配方2的碘值(I)从84.56 g/100 g降低到79.47 g/100 g,降幅为6.02%;稻米调和油的极性组分含量超标时间延长,饱和脂肪酸增长率较稻米油低,而多不饱和脂肪酸的降幅略高于稻米油;稻米调和油较稻米油的维生素E损耗率高。综合来看,稻米调和油的煎炸稳定性较好,并且也一定程度保留了稻米油的营养特性,配方2的煎炸性能更为优越。     

复合溶剂提取沙棘籽油的工艺条件研究

采用响应面优化了正己烷-丙酮复合溶剂浸提沙棘籽油的提取条件,并对沙棘籽油的理化性质进行分析.结果表明:最优条件为料液比1∶14、粉碎度35.00目、正己烷:丙酮为6∶4、浸提温度44.00℃、浸提时间1.84h,在该条件下沙棘籽油提取率为13.788%.沙棘籽油的碘价为156.30mg/100g,酸价为8.80mg KOH/g,皂化值为186.30mg KOH/g,水分及挥发物0.22%,过氧化值为9.21meq/kg,不皂化物含量为1.89%.     

水酶法提取樱桃籽油的工艺及理化性质

目的:优化水酶法提取樱桃籽油工艺,提高樱桃籽利用率。方法:在单因素试验基础上,运用混料设计对混合酶的混合比例进行优化,以确定最佳提取工艺条件,再对樱桃籽油的理化性质进行检测。结果:混合酶法提取樱桃籽油的最优酶解条件为：混合酶(m_维素酶∶m_果胶酶∶m_{酸性蛋白酶}为0.67∶0.10∶0.23)添加量2.0%,液料比(V_蒸馏水∶m_樱桃籽粉)10∶1 (mL/g),酶解温度45℃,pH 4.0,酶解4.0 h,樱桃籽油回收率达到93.18%,实际提取率为28.66%。所得樱桃籽油符合食用油安全标准。结论:混料设计辅助水酶法提取樱桃籽油的工艺具有可行性。     

花椒籽油品质及精炼效果研究

对不同产地或不同品种花椒籽主要组分及利用压榨法和浸出法提取的花椒籽毛油进行检测,并对花椒籽毛油精炼效果及精炼油品质进行分析研究。结果显示:4个花椒籽样品的粗脂肪含量为11.95%~25.41%,粗蛋白质含量为7.89%~11.03%,粗纤维含量为23.71%~31.27%;5个花椒籽毛油样品的酸值(KOH)为14.24~66.51 mg/g,过氧化值为9.01~31.47 mmol/kg;同一品种的花椒籽,其压榨毛油和浸出毛油的质量差别不大,但不同产地或不同品种的花椒籽,其毛油质量相差很大;所有花椒籽毛油的色泽均较深;花椒籽毛油经碱炼脱酸、吸附脱色和水蒸气蒸馏脱臭后,其酸值、过氧化值都可达到GB/T 22479—2008《花椒籽油》的质量指标,但反式脂肪酸含量较高。花椒籽毛油中不饱和脂肪酸含量在70%以上,其中亚麻酸含量为20%左右,棕榈酸含量超出国标中标识的上限值,其他脂肪酸含量均在国标范围之内。     

制油工艺对油茶籽油质量安全的影响分析

对6种制油工艺所得的普通油茶籽油进行了质量安全指标及活性成分的检测。结果表明,制油工艺对油茶籽油的品质和活性成分有明显的影响:油茶籽剥壳后液压榨所得油茶籽油的品质最好,其油的酸值和过氧化值最低,分别为2 mgKOH/g和0.01 g/100 g,且油色较浅,色值R 3.0,Y 33.9,脂肪酸中油酸含量最高;从活性成分来看,油茶籽全籽液压所得的油茶籽油中α-生育酚含量和角鲨烯含量均为最高,为17.8mg/100 g,油茶籽剥壳后液压所得油茶籽油中β-谷甾醇含量最高;压榨方式所得的油茶籽油苯并(a)芘超标的风险很小,是一种较为安全的制油方式;与螺旋榨相比,液压榨温度较低,较好保持了油茶籽油中固有的成分,保留了原有的生物活性物质。     

制油方式对油茶籽油品质及活性成分的影响

研究了普通螺旋榨、溶剂浸提、包饼液压和快速液压4种制油方式对油茶籽油品质及营养活性物质的影响。结果表明,在4种制油方式中,快速液压榨所得油的酸值与过氧化值最低,普通螺旋榨的最高。快速液压油脂肪酸组成中油酸含量最高,为82.85%;油中的α-生育酚含量最高,为29.8mg/100g,且角鲨烯与β-谷甾醇保存较好。单从油茶籽油品质及活性成分的保持上来看,快速液压是一种较为理想的制油方式。     

煎炸油中极性物质与酸价之间的相关性研究

本实验以油茶籽油、橄榄油和棕榈油为研究对象,研究经过180℃下油炸薯条后三种油的酸价与极性物质的相关性以及主要脂肪酸的变化。发现,三种油随着油炸时间的增加酸价(p0.05)显著增大。油茶籽油、橄榄油和棕榈油的最终酸价分别为0.32、0.66、0.58mg/g。经过20次油炸,三种油的总极性物质(TPC)显著增加,油茶籽油、橄榄油和棕榈油总极性物质分别为16.01%、20.91%和17.66%。随着油炸时间的增加,三种煎炸油的饱和脂肪酸含量显著增加。不饱和脂肪酸的含量变化较大,C18∶2和C18∶3显著下降,而C18∶1逐渐下降。     

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.     

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.     

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.     

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.     

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.