不同条件对蜂蜜发酵过程中高级醇生成的影响

为探究不同条件对酵母发酵蜂蜜过程中高级醇生成的影响,以蜂蜜、麦曲、酵母为原料,以高级醇含量为指标,通过单因素试验分别考察了发酵温度、酵母添加量、发酵时间、磷酸氢二铵添加量和发酵液糖度对酵母发酵蜂蜜过程中高级醇生成的影响。响应面优化结果表明,当麦曲添加量为4%,干酵母的加入量为0.2%,磷酸氢二铵添加量600 mg/L,起始发酵液的糖度为30.0%,pH为4.5,培养温度为34℃,培养时间为4 d,在此条件下得到高级醇的最低值43.72 mg/L。     

响应面法优化红曲调味酒的发酵条件

为探究不同条件对红曲调味酒发酵的影响,以蜂蜜、红曲、酵母为原材料,以高级醇含量为指标,通过单因素试验分别考察了发酵温度、发酵液pH值、酵母添加量、发酵时间、磷酸氢二铵添加量和发酵液糖度对酵母发酵蜂蜜过程中高级醇生成的影响。响应面优化结果表明,红曲调味酒的最佳优化条件为:培养温度为28℃,培养液pH为5,红曲米添加量为4%,酵母添加量为0.2%,糖浓度为25.4%,磷酸氢二铵的添加量为1000mg/L,培养时间为6d。     

响应面法优化桂花蜂蜜酒发酵工艺

以干桂花、蜂蜜为主要原材料,研究桂花蜂蜜酒发酵最佳工艺条件。在单因素试验基础上,选择干桂花加入量、麦曲加入量、温度3个因素为响应因子,酒精度为响应值,通过响应面试验对桂花蜂蜜酒进行发酵工艺优化。结果表明,最优发酵工艺条件为:糖度28%、酵母加入量0.2%、铵盐质量浓度0.9 g/L、麦曲添加量9%、温度28℃、培养时间6 d,此发酵条件下干桂花蜂蜜酒酒精度为16.98%vol。     

响应面法优化芒果蜂蜜果酒发酵工艺的研究

以攀枝花的凯特芒果和野拔子蜂蜜为原料,考察酵母添加量、初始糖度和发酵温度对芒果蜂蜜果酒的品质的影响,并通过单因素试验和响应面试验设计优化发酵工艺。结果表明,芒果蜂蜜果酒最佳发酵工艺条件为酵母添加量为0.06%,初始糖度为20%,发酵温度为26 ℃。在此发酵条件下,芒果蜂蜜果酒感官评分为83.0分,酒精度为11.0%vol,颜色呈橙黄色,其理化指标及微生物指标均符合国家相关标准。     

氮源种类及浓度对蜂蜜酒发酵和杂醇油含量的影响

探讨氮源种类及浓度对蜂蜜酒发酵和杂醇油含量的影响,为蜂蜜酒的酿造提供参考.实验以酿酒酵母(Saccharomyces cerevisiae Hansen)1450为实验菌株,以荆条蜜为原料,分别添加硫酸铵、磷酸铵、磷酸氢二铵、乙酸铵、酵母膏、蛋白胨和豆芽汁作为蜂蜜酒发酵培养基氮源.依据GB/T 15038-2006<葡萄酒、果酒通用分析方法>测定发酵液酒精度、还原糖、总酸和挥发酸,用二甲氨基苯甲醛比色法测定杂醇油.结果表明,铵盐中以磷酸氢二铵酒精度高,有机氮源中以酵母膏酒精度高,添加有机氮源蜂蜜酒中杂醇油含量高.     

黑木耳红枣复合果醋酒精发酵工艺的研究

以黑木耳、红枣为主要原料酿造复合果醋,采用响应面法优化果醋的酒精发酵工艺条件。选取酵母接种量、发酵温度、初始糖度为影响因子,以发酵液的酒精度为响应值,在单因素试验基础上,采用Box-Behnken设计建立数学模型。结果表明:黑木耳红枣复合果醋酒精发酵的最佳工艺参数为酵母接种量4%,发酵温度30℃,初始糖度12.5%,发酵7天,在此优化条件下,发酵液的酒精度为11.7%,与模型预测值基本一致。     

山乌桕蜂蜜酒的酿造工艺研究

以山乌桕蜜为原料,通过液态深层发酵酿制蜂蜜酒。系统研究了花粉和阿米诺酶添加量、酵母种类、酵母接种量、起始糖度、温度、起始pH值对蜂蜜酒发酵的影响。确定了蜂蜜酒酿制的最适酵母为黄酒酵母以及最佳工艺参数为花粉添加量0.15%(w/v)、阿米诺酶添加量0.15%(w/v)、接种量0.2%(w/v)、起始糖度23%(w/v)、温度28℃、起始pH值3.6。经过7d的发酵以后,山乌桕蜂蜜酒的酒精度可以达到8.0%vol,残总糖降为8.5%,其气味芳香、口感好。     

丹参保健酒发酵条件优化

该研究利用丹参和赤砂糖为主要原料进行发酵生产丹参保健酒,以丹参保健酒中的总黄酮与总酚酸含量作为评价指标,通过单因素试验和正交试验对丹参添加量、酵母接种量、发酵初糖度、发酵温度及发酵pH值进行优化。结果表明,丹参保健酒最优工艺条件为：丹参添加量10%、酵母接种量0.015%、发酵液初总糖275 g/L、发酵温度28 ℃、发酵液pH值4。在此优化条件下,丹参保健酒酒精度为12.6%vol,总黄酮含量为506 mg/L、总酚酸含量为354 mg/L。     

发酵型草莓蜂蜜酒的工艺优化研究

以草莓为主要原料,用蜂蜜调整糖度,通过单因素实验与正交实验对复合酶法提取草莓汁的工艺条件和草莓蜂蜜酒的发酵工艺进行优化研究.结果表明,草莓的最佳酶解工艺条件为:复合酶添加量0.2％(果胶酶与纤维素酶添加量比例为1∶4),酶解温度50℃,pH4.5,酶解时间4.0h,草莓出汁率可达90.2％.草莓蜂蜜酒的发酵工艺条件为:发酵初始糖度16％,酵母菌直投用量0.4％,发酵温度30℃,发酵时间4d,酒精度可达8.4％vol.     

响应面优化库尔勒香梨果醋发酵工艺的研究

以新疆库尔勒香梨果汁为原料,通过酒精发酵和醋酸发酵工艺,研究了不同初始糖度、温度、接种量、酒精度和液料比等单因素对发酵效果的影响,结合响应面优化最终确定香梨果醋酒精发酵的最佳工艺参数:初始糖度为16 Bx°,酵母添加量为0.04%,发酵温度为28℃,发酵时间为5 d,得到酒精度为8%vol香梨果酒;醋酸发酵的最佳工艺参数:初始酒精度为8%,接种量为8%,温度为32℃,发酵时间6 d,制得酸度为5.82 g/100 m L的库尔勒香梨果醋。     

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.     

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.     

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.     

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.     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.