低脂豆腐脑的制备工艺研究

以低温豆粕为原料通过溶出、过滤、热处理和凝固等工艺制备低脂豆腐脑。正交试验结果表明,豆腐脑的最佳工艺条件为:GDL浓度为0.4%,凝固时间为30 min,凝固温度为85℃。在该条件下,豆腐脑的感官综合评分为94分,凝胶强度为14.738 g。脂肪含量分析显示,低脂豆腐脑的脂肪仅占干物质重的1.4%,明显低于普通的大豆豆腐脑。     

高亚麻酸含量的豆腐脑加工工艺

以低温豆粕和紫苏油为原料通过溶出、过滤、匀质、热处理和凝固等工艺制备高亚麻酸豆腐脑。正交试验结果表明,豆腐脑的最佳工艺条件为:GDL浓度为0.5%,凝固时间为30min,凝固温度为80℃。在该条件下,豆腐脑的感官综合评分为90分,凝胶强度为21.693 g。脂肪成分分析表明,高亚麻酸豆腐脑的α-亚麻酸含量达到60.274%,远高于普通豆腐脑的8.39%。     

黑豆腐脑的加工工艺研究

以黑豆和黄豆为原料通过制浆、灭菌和凝固等工艺制备黑豆腐脑。考察了黑豆与黄豆比例、GDL浓度、凝固时间、凝固温度对成脑的影响,单因素和正交试验结果表明,豆腐脑的最佳工艺条件为:黑豆与黄豆比例为1/1(g/g),GDL浓度为0.5%,凝固时间为20min,凝固温度为90℃。在最佳条件下,豆腐脑的感官综合评分为73分,凝胶强度为17.752 g。     

复合凝固剂在黑豆豆腐加工中的应用

为确定黑豆豆腐的最佳工艺条件,以黑豆和水为主要原料,通过单因素及正交试验考察复合凝固剂质量比、料液比、凝固温度及凝固时间对黑豆豆腐的感官品质、质构特性、色泽、含水率、蛋白质含量及脂肪含量的影响,确定最佳参数。结果表明：黑豆豆腐最佳工艺条件为复合凝固剂质量比（谷氨酰胺转氨酶：硫酸钙）1∶3.00、料液比1∶8.0（g/mL）、凝固温度78℃、凝固时间27 min。此条件下黑豆豆腐的感官评分为93.0,含水率为60.8%,蛋白质含量为16.7%,脂肪含量为8.2%。     

低脂花生豆腐脑的工艺研究

以花生粕和低温豆粕为原料,葡萄糖酸-δ-内脂(GDL)为凝固剂,探讨低脂花生豆腐脑的制作工艺。以使用物性仪测量的凝胶强度作为衡量豆腐脑品质的指标,并辅以感官评价,通过设计正交试验,确定其最佳的工艺参数为:花生粕的添加量为20%,GDL含量为0.6%,凝固时间为30 min,凝固温度为90℃。在最佳条件下,凝胶强度为19.671 g。     

豌豆豆腐的研制

以豌豆和大豆为原料,以葡萄糖酸-δ-内酯(GDL)为凝固剂,对豌豆、大豆复合豆腐的加工工艺进行了研究.探讨了浸泡条件、豌豆浆与大豆浆的复合比例、豆浆加热条件以及凝固条件对豆腐品质的影响.结果显示:豌豆最佳浸泡水温为20℃,浸泡17 h;在豌豆浆中加入一定比例的大豆豆浆可以提高豆浆的蛋白质含量,增加豆腐的凝胶强度和降低失水率,最低复合比例为豌豆浆:大豆浆按1:1比例混合;复合豆浆的最佳加热条件为95℃水浴加热15 min;最适凝固条件为GDL用量0.3%,CaSO4用量0.1%;凝固温度95℃,凝固时间40 min.     

花生分离蛋白制备工艺研究

采用碱提酸沉法从低变性脱脂花生粕中提取花生分离蛋白。探讨了碱提温度、碱提时间、碱提固液比等因素对产品蛋白质含量和得率的影响。通过正交试验优化制备花生分离蛋白的最佳工艺条件为:碱提温度55℃,碱提2次,每次1.5 h,碱提固液比1∶9,碱提pH 9.0,酸沉pH 4.5。在此条件下产品的蛋白质含量为90.87%(N×6.25,干基),得率最高可达38.65%。该产品的氮溶解指数为68.46%,持水性2.3 g/g,吸油性1.3 mL/g,乳化性50.4%,乳化稳定性56.55%。     

花生露制备条件对可溶性蛋白溶出率的影响

以花生仁为原料,可溶性蛋白溶出率为评价指标,采用考马斯亮蓝法研究液料比、磨浆温度、磨浆pH和磨浆时间对花生可溶性蛋白溶出率的影响。采用正交试验法优化制备工艺,得到制备花生乳的最佳工艺条件:液料比4∶1(mL/g)、磨浆温度60℃、磨浆时间8 min、磨浆pH 7。结果表明:液料比、磨浆温度、磨浆pH和磨浆时间对花生可溶性蛋白溶出率影响显著。     

响应曲面法优化可食玉米醇溶蛋白膜制备工艺

通过单因素试验和响应曲面法,优化了可食玉米醇溶蛋白膜制备工艺。以乙醇体积分数、固液比、油酸用量和膜液加热温度为因素,以断裂伸长率(E)、拉伸强度(TS)、水蒸气透过系数(WVP)为响应值对实验进行响应面设计,建立了断裂伸长率(E)、拉伸强度(TS)、水蒸气透过系数(WVP)的回归模型,优化的工艺条件为乙醇体积分数82%、固液比(g∶mL)1∶10、油酸用量0.5mL/g玉米醇溶蛋白、膜液加热温度70℃。     

醇洗豆粕对大豆分离蛋白功能性质的影响(Ⅰ)--凝胶性能

为了探讨醇洗豆粕对大豆分离蛋白凝胶性能的影响。以醇洗豆粕为原料制备的大豆分离蛋白，其凝胶性能得到明显的改善。通过正交试验优化，生产凝胶型大豆分离蛋白的最佳工艺条件为：乙醇浓度85％(V／V)、浸提温度30℃、浸提时间45min、固液比1：4。所得产品的蛋白含量(干基)为96．52％，蛋白质分散指数为94．41％，凝胶硬度为285．4g，凝胶弹性为153．1g。     

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.     

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.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.