响应面法优化火龙果酒发酵工艺及其鸡尾酒的调配

以火龙果汁为主要原料,采用响应面法优化火龙果酒的发酵工艺,对起始糖度、起始pH值、发酵温度、菌种接种量等因素进行单因素试验,在此基础上进行响应面优化设计。结果表明,火龙果酒发酵的最佳工艺条件为起始糖度22.6%、起始pH值3.6、发酵温度15℃、酵母接种量1.0%,在此优化条件下,火龙果的感官评分为88.64分。再以火龙果酒为基酒,配以火龙果汁15%、白糖水25%,调配出品火龙果鸡尾酒。该饮品口感较佳,营养丰富,含有维生素、微量元素,具有一定的保健功效。     

4种商用酿酒酵母发酵火龙果酒的发酵动力及成分变化

4种商业酿酒酵母R2、D254、DV10和RC212用来评估其对红芯火龙果酒的发酵动力及发酵过程中产生的非挥发性以及挥发性成分的影响。结果表明,不同酵母对火龙果酒发酵及成分的影响不同。RC212酵母与R2酵母具有更快的发酵速率;R2酵母发酵的火龙果酒酒精度为11.47%vol、甜菜苷含量为581.44 mg/L、多酚含量为272.52μg/m L,显著高于其他3种酵母发酵的火龙果酒。清汁发酵的火龙果酒主要有机酸为苹果酸和琥珀酸,带渣发酵的则为琥珀酸、苹果酸和柠檬酸。挥发性香气成分中,醇类物质最为丰富,次之的酯类和羰基类物质相当。除醇类物质外,D254发酵的火龙果酒酯类物质最为丰富,其次是R2发酵的火龙果酒。综合考虑,R2酵母及采用清汁发酵较适合红芯火龙果酒的酿制。     

不同酵母发酵的火龙果酒抗氧化活性及颜色变化

研究4种不同酵母发酵的火龙果酒在发酵过程中总酚、甜菜苷、抗氧化活性和颜色的变化规律。结果表明,在发酵过程中,4种酵母发酵火龙果酒的总酚、甜菜苷含量均呈下降趋势;L*值、a*值均升高,b*值降低。酵母RC212发酵的火龙果酒的多酚含量最高为272.5 μg/mL,其对DPPH自由基清除率IC50最低为22.98%;酵母R2发酵的火龙果酒的羟自由基清除率、总还原力IC50最低,分别为8.84%、28.52%,并且甜菜苷含量最高为581.4 mg/L。酵母RC212与酵母R2发酵的火龙果酒在抗氧化物质含量、抗氧化活性及红色素稳定性方面均优于酵母DV10与酵母D254发酵的火龙果酒。     

红芯火龙果酒酿酒酵母的筛选

以筛选适宜的酿造火龙果酒的酵母为研究目标,采用产于广西和浦县的第3代红皮红肉火龙果为原料,对经初选后得到的4种商业酵母(R2、RC212、D254、DV10)分别进行耐SO2能力、发酵糖能力和耐糖能力的研究.分析不同SO2浓度和糖浓度下酵母的降糖能力和酵母菌的生长繁殖情况,并通过综合评价筛选出酵母R2为较适合红芯火龙果酒发酵的酵母.     

偶联协酵法生产红心火龙果酒工艺初探

采用多菌协联发酵等前沿加工技术,使用新鲜红心火龙果为发酵原料,通过挑选、清洗、破碎榨汁以后添加实验室自筛的火龙果酒酵母和生香酵母,采用多菌协联发酵,所得的产品口味纯正、香气突出浓郁、回味协调丰盈的火龙果酒。     

响应面法优化二次发酵红曲火龙果酒发酵工艺

红曲火龙果酒是以火龙果为原料,采用酵母一次发酵、红曲二次发酵制得发酵酒。在单因素试验基础上,应用Box-Behnken中 心组合试验设计建立一次发酵、二次发酵数学模型进行响应面分析,优化火龙果酒发酵工艺。结果表明,红曲火龙果酒一次发酵优化 条件为发酵时间5.3 d,发酵温度29.3 ℃,酵母接种量0.024%,加糖量17.4%,此条件下制得一次发酵样品感官评分为86.8分。 二次发酵 优化条件为发酵时间62 h,发酵温度30.2 ℃,红曲米添加量9.2%,此条件下制得的红曲火龙果酒成品总酯含量为15.42 g/L,感官评分 为91.1分。     

火龙果酒酿酒酵母的筛选

为筛选出适合酿造火龙果酒的菌种,分别对10种商业酿酒酵母进行发酵能力进行综合评价和筛选。结果表明:在发酵温度25℃、菌种添加量0.01%的条件下,适合红芯火龙果酒发酵的菌种为F15酵母,所得的酒体红色,香味浓郁,具有明显的火龙果香气及酒香。     

基于混菌发酵改善火龙果酒品质

为了使火龙果酒的品质得到更好地提升,该研究采用酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌发酵火龙果酒,分析火龙果酒发酵过程中的理化指标及风味物质。研究发现,酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌联合发酵（Zw组）能显著提高糖的利用率,减少甜菜红素和酚类物质的损失,生物降酸能力也很好。利用液相色谱-质谱法检测发酵样品的有机酸,结果表明,火龙果酒中主要的有机酸为乳酸和乙酸,而柠檬酸的相对含量最低。相对于其他发酵组,Zw组（10.28%）有机酸相对含量较低,说明植物乳植杆菌有良好的降酸能力。利用气相色谱-质谱法检测发酵样品的香气成分,共检测出63种香气成分,Zw组发酵样品中醇类物质的种类和浓度明显提高,果香味与花香味增强。感官评价结果表明,Zw组在色、香、味方面得分最高,酸甜适中,颜色鲜亮。因此,利用酿酒酵母、库德里阿兹威毕赤酵母和植物乳植杆菌联合发酵,有利于改善火龙果酒的口感,增加其香气复杂度,提高品质。该研究首次利用酿酒酵母、非酿酒酵母和植物乳植杆菌联合发酵火龙果酒,可为火龙果酒品质控制和技术开发提供必要的理论基础。     

火龙果酒酿酒酵母的筛选

为筛选出适合酿造火龙果酒的菌种,分别对10种商业酿酒酵母进行发酵能力进行综合评价和筛选。结果表明:在发酵温度25℃、菌种添加量0.01%的条件下,适合红芯火龙果酒发酵的菌种为F15酵母,所得的酒体红色,香味浓郁,具有明显的火龙果香气及酒香。     

响应面法优化仙人掌果-红心火龙果酒发酵工艺

该试验以仙人掌果、红心火龙果为原料制作复合果酒,并优化最佳发酵工艺条件。通过单因素和响应面试验探讨仙人掌果果肉质量与红心火龙果果肉质量比、焦亚硫酸钾添加量、发酵温度、初始糖度、酵母接种量对仙人掌果-红心火龙果酒发酵产酒精量及感官评分的影响。结果表明,仙人掌果-红心火龙果酒的最佳发酵条件为：果肉质量比1∶1,焦亚硫酸钾0.03%,发酵温度24 ℃,初始糖度22 °Bx,酵母接种量0.03%,此条件下制得仙人掌果-红心火龙果酒的酒精度11.89%vol,感官评分为95.5分。果酒清澈色泽鲜艳,酒香醇厚协调,具有典型果香。     

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.     

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.     

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.