布朗李杏仁复合蛋白饮料稳定性研究——乳化稳定剂对稳定性的影响

试验采用布朗李和杏仁为主要原料,对布朗李杏仁复合蛋白饮料的稳定性进行研究。主要探讨了单一乳化剂(分子蒸馏单甘酯、司盘60和吐温40)、复合乳化剂(将分子蒸馏单干酯和司盘60分别与吐温40进行复合,配合成不同亲水亲油平衡值(HLB值)的复合乳化剂)对布朗李杏仁复合蛋白饮料的乳化效果;单一稳定剂(黄原胶、羧甲基纤维素钠和卡拉胶)、复合稳定剂(黄原胶和卡拉胶按比例复合)对布朗李杏仁复合蛋白饮料稳定性的影响;试验表明,乳化稳定剂对布朗李杏仁复合蛋白饮料的稳定性影响显著。以复合汁的稳定系数作为测定指标,通过对单一乳化剂、复合乳化剂、单一稳定剂和复合稳定剂的筛选试验。结果表明,复合乳化剂(HLB=8)司盘60∶吐温40=25∶11,用量为0.10%;黄原胶∶卡拉胶=1∶2,用量为0.09%,布朗李杏仁复合蛋白饮料的稳定性最佳。     

苹果籽蛋白质饮料稳定性的研究

对单甘脂、蔗糖脂和稳定剂在苹果籽蛋白饮料中的乳化稳定性进行了研究,结果表明苹果籽蛋白饮料中乳化剂和稳定剂的最佳配方为0.8%单甘酯,1.2%蔗糖酯、0.15%黄原胶和0.15%瓜尔豆胶.     

红薯大米牛乳复合饮料工艺研究

研究了以红薯、大米、牛乳为原料制备饮料的工艺。研究结果表明:α-淀粉酶酶解红薯的最优工艺条件为:料水比3:20(m/m),酶解温度70℃,酶解时间30 min,加酶量0.02 g/100 g红薯粉,酶解后取清液制备饮料。饮料的最佳配方为:红薯汁40%、大米汁40%、牛乳20%,柠檬酸添加量0.03%。复合乳化剂(分子蒸馏单甘酯:蔗糖酯:司盘60=1:1:2)添加量为0.15%;复合稳定剂(黄原胶:羧甲基纤维素钠=1:2)添加量为0.12%。此工艺生产的饮料具有较好的品质及风味。     

枸杞花生乳中乳化剂和稳定剂的研究

为了提高枸杞花生乳的稳定性,研究了乳化剂和稳定剂复合使用的稳定效果。结果表明,当乳化剂为0.10%蔗糖酯、0.15%单甘酯,稳定剂为0.05%黄原胶(XG)、0.15%羧甲基纤维素钠(CMC-Na)时,枸杞花生乳稳定效果最佳。     

新型板栗饮料稳定性研究

为了解决新型板栗饮料在加工过程中易出现沉淀的问题,寻找最适合板栗饮料稳定所需要的稳定剂和乳化剂。研究了黄原胶、羧甲基纤维素钠(carboxymethylcellulose sodium,CMC)、单硬脂肪酸甘油酯、脂肪酸蔗糖酯、海藻酸丙二醇酯(propylene glycol alginate,PGA)等稳定剂和乳化剂对新型板栗饮料稳定性的影响。在单因素实验的基础上以黄原胶、CMC、PGA和单硬脂肪酸甘油酯为影响因素进行正交实验,得出最佳复合稳定剂质量浓度为:黄原胶1 g/L,CMC 4 g/L,PGA 2 g/L,单硬脂肪酸甘油酯1 g/L,新型板栗饮料稳定性达到71. 107%,根据极差分析得出影响板栗饮料稳定性的因子主次顺序依次为黄原胶> PGA> CMC>单硬脂肪酸甘油酯。该研究为解决板栗饮料加工过程中的稳定性问题提供理论依据。     

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。     

薏苡仁饮料稳定剂配方优化

以薏苡仁为主要原料研制饮料,探讨了羧甲基纤维素、果胶、海藻酸钠、黄原胶、卡拉胶5种稳定剂对饮料稳定性的影响。通过单因素和响应面试验优化筛选出最佳的稳定剂的组合和用量。结果表明:采用0.03%羧甲基纤维素、0.04%果胶、0.10%黄原胶复合而成的稳定剂可有效地提高薏苡仁饮料的稳定性,且所得的饮料口感细腻、色泽纯正。     

黄花梨鲜白莲复合饮料加工工艺

以黄花梨、鲜白莲为主要原料,运用正交试验法对黄花梨鲜白莲复合饮料的加工工艺进行研究,结果表明复合饮料的最佳配方为:黄花梨汁40%,莲子乳35%,蔗糖7%;复合乳化稳定剂最适配比为单甘酯0.05%,蔗糖酯0.15%,黄原胶0.05%,海藻胶0.10%,卡拉胶0.05%.     

南瓜籽保健饮料的研制

分析了南瓜籽仁的主要营养成分,研究了以木糖醇为甜味剂的南瓜籽饮料的生产工艺及影响其稳定性的各种因素。认为以80℃热水浸泡8h蛋白质提取率最高,以0.05%单甘酯,0.05%蔗糖酯,0.07%黄原胶,0.03%葡甘聚糖,0.15%三聚磷酸钠组成的复合稳定剂,及35～40MPa的均质压力,70℃左右的均质温度和118℃,15min的杀菌条件,制得的南瓜籽饮料稳定性最高,口味也佳。     

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.     

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.     

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.