不同乳化稳定剂对全谷物糙米营养乳稳定性的影响及其配比优化

分析了影响全谷物糙米营养乳饮料稳定性的主要因素,筛选了合适的乳化稳定剂并对其配比进行了优化,探讨了蔗糖和三聚磷酸钠等品质改良剂对体系稳定性的影响。结果表明:全谷物糙米营养乳饮料的乳化剂蔗糖脂肪酸酯与蒸馏单硬脂酸甘油酯的优化复配比例为2∶8,复合乳化剂的添加量为0.20%;筛选出黄原胶、羧甲基纤维素和微晶纤维素为体系的稳定剂,其优化配方为黄原胶0.05%,羧甲基纤维素0.15%,微晶纤维素0.08%。进一步发现,蔗糖和三聚磷酸钠可以改善体系的稳定性,但当蔗糖添加量达到4%后,体系的离心悬浮比逐渐降低。     

响应面优化乳清雪菊酒稳定剂的研究

为了研究不同稳定剂对乳清雪菊酒稳定性的影响,并得到最佳的稳定剂复配方案,本文以发酵的乳清雪菊酒为原料,通过添加黄原胶、海藻酸丙二醇酯(PGA)、羧甲基纤维素钠(CMC-Na)、卡拉胶、蔗糖酯和果胶6种不同稳定剂进行单因素考察,以沉淀率为考察指标,筛选出稳定效果较好的3种稳定剂,利用响应面优化法进行复配稳定剂的优化,以此改善乳清雪菊酒的不稳定性。实验结果表明,乳清雪菊酒中稳定剂CMC-Na的添加量为0.16%、蔗糖酯的添加量为0.11%、果胶的添加量为0.07%时产品的稳定性最优,沉淀率为1.27%,复配稳定剂能够较好的改善产品的不稳定性。     

贝母乳饮料的稳定性研究

以贝母和牛乳为主要原料制成贝母乳饮料,研究了乳化剂、稳定剂对贝母乳饮料稳定性的影响。在单因素实验的基础上,选择果胶、CMC-Na和复合乳化剂作为实验因素,进行Box-Behnken中心组合实验设计,采用响应面法(RSM)评估贝母乳饮料的稳定性。结果表明,稳定剂和乳化剂的最佳用量为果胶0.13%、CMC-Na0.05%、复合乳化剂0.10%时,贝母乳饮料的沉淀率为3.08%。     

黑米黑芝麻复合谷物乳稳定剂配方优化

以黑米和黑芝麻为主要原料研制复合谷物乳饮料,探讨了蔗糖脂肪酸酯、蒸馏单硬脂酸甘油酯、CMC、琼脂、海藻酸钠,黄原胶及卡拉胶对谷物乳稳定性的影响.通过响应面实验优化筛选出最佳的乳化剂和增稠剂的组合和用量.结果表明:采用0.11％蔗糖脂肪酸酯,0.12％蒸馏单硬脂酸甘油酯和0.13％ CMC复合而成的稳定剂可有效提高黑米黑芝麻复合谷物乳的稳定性,且所得黑米黑芝麻复合谷物乳色泽纯正、口感细腻.     

红树莓调配型酸性乳饮料乳化稳定性研究

研究红树莓酸性乳饮料稳定性、乳化性问题,采用单因素和正交试验,通过测定样品的沉淀率、透光率、乳化稳定性、黏度等指标来评价饮料的乳化稳定性.结果表明:样品最佳稳定剂为黄原胶(0.35%)、果胶(0.20%)、羧甲基纤维素钠(0.25%).复合乳化剂配比为单甘脂:蔗糖酯=7:3,总添加量0.05%时能使体系达到最佳的乳化效果.     

酸奶冰淇淋乳化稳定剂的开发研究

通过单因素实验和正交实验,以感官评价和冰淇淋的浆料黏度、膨胀率、融化率为指标,对羧甲基纤维素钠(CMC-Na)、瓜尔胶、黄原胶、刺槐豆胶组成的复配稳定剂和单硬脂酸甘油酯、山梨醇单硬脂酸酯(司盘60)组成的复配乳化剂进行优化,确定了应用酸奶粉的酸奶冰淇淋的复配乳化稳定剂。结果表明,该冰淇淋的复合乳化稳定剂优化配方为:CMC-Na 0.35%,瓜尔胶0.030%,黄原胶0.040%,刺槐豆胶0.040%,单硬脂酸甘油酯0.03%,司盘60 0.03%,产品的膨胀率为96.0%,融化率为4.8%(均为质量分数,下同),感官评分为98分。     

复配稳定剂对马奶啤酒稳定性的影响

以马奶啤酒为研究对象,通过对海藻酸钠、海藻酸丙二醇酯(PGA)、果胶、羧甲基纤维素钠(CMC-Na)和黄原胶5种不同稳定剂添加量的单因素实验考察,筛选出稳定效果较好的3种稳定剂,采用响应面设计实验进行稳定剂复配,来改善马奶啤酒的稳定性。响应面实验最终优化得到复配稳定剂的最优添加量为CMC-Na%:PGA%:果胶%=0.02:0.03:0.03。在此条件下,马奶啤酒的离心沉淀率为4.85%,且样品状态稳定。     

探索不同乳化剂对含谷物调制乳饮料乳化稳定性的影响

通过单因素实验及感官品质评价方法,以稳定性及感官评价为指标,研究了蔗糖脂肪酸酯、单硬脂酸甘油酯、双乙酰酒石酸单双甘油酯、硬脂酰乳酸钠、聚甘油脂肪酸酯(三聚)、聚甘油脂肪酸酯(六聚)六种常用乳化剂单一和复配添加对含谷物调制乳饮料乳化稳定性的影响。结果表明,0.08%单硬脂酸甘油酯和0.03%双乙酰酒石酸单双甘油酯复配添加时,含谷物调制乳饮料的乳化稳定效果最好,常温贮存6个月观察,产品无沉淀,无明显脂肪上浮,理化指标均正常。     

响应面试验优化葡萄籽鹰嘴豆复合饮料稳定剂配方

为了研究不同稳定剂对葡萄籽鹰嘴豆复合饮料稳定性的影响,并得到最佳的稳定剂复配方案,以葡萄籽鹰嘴豆复合饮料为原料,通过添加黄原胶、卡拉胶、果胶、羧甲基纤维素钠(CMC-Na)、海藻酸钠5种不同稳定剂进行单因素考察,以稳定系数、沉淀率为考察指标,筛选出稳定效果较好的3种稳定剂,利用响应面优化法进行复配稳定剂的优化。结果表明,葡萄籽鹰嘴豆复合饮料中稳定剂添加量为海藻酸钠0.04%、黄原胶0.04%、果胶为0.03%时,产品的稳定性最优,稳定系数为98.877%,平均沉淀率为1.064%,试验得出的复配稳定剂能够提高产品的稳定性。     

黑糯米乳饮料乳化稳定剂配方与均质工艺优化

试验以黑糯米为主要原料研制谷物乳饮料,分析了影响黑糯米乳饮料稳定性的主要因素,对其乳化稳定剂的配方及均质加工工艺进行了系统优化。结果表明:黑糯米乳饮料的最适HLB为7.48,即蔗糖脂肪酸酯与蒸馏单硬脂酸甘油酯的最佳质量比为4︰6,复合乳化剂的添加量为0.08%;稳定剂的最佳配方为羧甲基纤维素0.08%、黄原胶0.14%和海藻酸钠0.05%;最佳的均质条件为均质压力20 MPa,均质温度60℃,均质次数2次。     

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.