响应面法优化黄芪保健酸奶的工艺研究

通过单因素试验考察了黄芪多糖添加量、蔗糖添加量、菌种接种量、发酵时间对感官评分的影响,再采用响应面法优化黄芪保健酸奶的发酵工艺,最终确定黄芪保健酸奶的最佳发酵条件为:蔗糖添加量10%,黄芪多糖添加量5%,发酵时间为6 h,此工艺条件下制得的黄芪酸奶的感官评分为88分。     

响应面法优化黄芪保健酸奶工艺研究

通过单因素试验法考察黄芪多糖添加量、蔗糖添加量、菌种接种量、发酵时间对感官测评得分的影响范围。再通过采用响应面法优化黄芪保健酸奶发酵工艺。最终确定黄芪保健酸奶的最佳发酵条件为蔗糖添加量10%、黄芪多糖添加量5%,发酵时间为6h,感官测评得分为88分。     

响应面法优化黄芪保健酸奶工艺研究

通过单因素实验法考察黄芪多糖添加量、蔗糖添加量、菌种接种量、发酵时间对感官测评得分的影响范围,再采用响应面法优化黄芪保健酸奶发酵工艺,最终确定黄芪保健酸奶的最佳发酵条件为蔗糖添加量10%,黄芪多糖添加量5%,发酵时间6 h,所得产品感官测评得分为88分。     

南瓜发酵酸奶的工艺研究

以鲜奶和南瓜为主要原料,以保加利亚乳杆菌为发酵菌种,对南瓜发酵酸奶的工艺进行了研究。通过正交实验确定出发酵工艺的各个工艺参数和酸奶的最佳配方,制成一种营养丰富、风味独特并具有保健功效的南瓜酸奶。实验结果表明,该酸奶最佳配方为南瓜浆10%,蔗糖量8%,乳酸菌接种量3%,稳定剂用量0.2%。最佳复合稳定剂为卡拉胶∶海藻酸钠∶CMC-Na=1∶1∶2,发酵温度42℃,发酵时间4.5h。     

益智核桃酸奶配方初步研究

采用正交实验设计,对核桃酸奶配方中的核桃与牛乳配比量、接种量、牛磺酸添加量进行研究。结果表明,配方为核桃乳与牛乳配比1∶4、接种量为4%、5%牛磺酸溶液添加量为0.15%的酸奶品质和风味俱佳。     

植物型保健酸奶的制备工艺

本文研究植物型保健酸奶。植物型车前草酸奶的优质配方为酸奶与车前草汁1∶1的比例,蔗糖的添加量为7%,发酵温度40℃,发酵时间5 h,它喝起来不仅细腻香甜可口,还可以消炎止泻利尿解毒。蒲公英酸奶的优质配方为蒲公英汁与酸奶1∶1的添加量,蔗糖添加量5%,发酵温度40℃,发酵时间5 h,既清热解毒又可以改善便秘,还具有强大的保健功能。牛蒡酸奶的优化配方为牛蒡汁与酸奶1∶1的添加量,蔗糖添加量5%,发酵温度40℃,发酵时间5 h,既可以驱热风散还可以降三高,还具有减肥功效。桑菊酸奶的优化配方是桑叶粉菊花汁的混合液与酸奶1∶1的添加量,蔗糖7%的添加量,40℃发酵5h,具有清热解毒,化痰止咳的功效,还可以维护肠道,促进消化吸收补充肠道里的有益菌营养。但是车前草、桑菊都是寒性食物,不能经常食用或者与热性食物同食。     

羊奶酸奶加工技术的研究

对羊奶酸奶加工技术进行了研究。结果表明:通过乳酸菌发酵能够消除羊奶膻味,嗜酸乳杆菌和嗜热链球菌是生产羊奶酸奶的适宜菌种,当菌种配比为1∶1,菌种添加量为3%,加糖量为9%时,羊奶酸奶质量较好。     

双歧杆菌发酵对羊酸奶食用品质的影响

在使用传统发酵剂的基础上研究了添加双歧杆菌发酵对羊酸奶食用品质的影响情况,通过用单因素实验和正交实验,以羊酸奶的滴定酸度、保水力、感官评分和质构特性为指标,优化出双歧杆菌羊酸奶的最佳发酵工艺条件。结果表明:当加糖量为7%,接种量为6%(均为质量分数),菌种比例为1∶1∶2,培养温度为42℃时,双歧杆菌羊酸奶的食用品质最好。     

红豆酸奶配方工艺优化研究

以红豆、全脂乳粉、蔗糖为原料,加工处理发酵成红豆酸奶,研究红豆浆料水比、红豆浆添加量及蔗糖添加量对红豆酸奶品质的影响,通过单因素试验和响应面分析确定出红豆酸奶的最佳工艺配方为:红豆浆料水比1∶4(g/mL),红豆浆添加量44%,蔗糖添加量7%,用此配方加工出的红豆酸奶感官评分为92.11分。     

蜂蜜酸奶的研制

以新鲜优质的蜂蜜和牛奶为原料,以保加利亚乳杆菌为发酵菌种,对蜂蜜酸奶的工艺进行了研究。通过正交实验确定出发酵工艺的参数和产品的最佳配方,研制出了一种具有独特风味的保健酸奶。试验结果表明:蜂蜜量12%,接种量3%,蔗糖量1%,最佳复合稳定剂为琼脂∶CMC=0.1∶0.1,发酵温度42℃,发酵时间5h。     

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.