复合澄清剂对红树莓果酒的澄清效果研究

以红树莓为原料发酵酿造红树莓果酒,并将壳聚糖和皂土作为复合澄清剂,探究其澄清效果及稳定性。以红树莓果酒透光率为响应值,采用Box-Behnken中心组合试验和响应面分析法,研究复合澄清剂比例、水浴温度和水浴时间对红树莓果酒澄清效果的影响。结果表明复合澄清剂澄清红树莓果酒的最佳工艺参数为:壳聚糖和皂土的质量比为3∶1、水浴温度45℃、水浴时间35 min,在此条件下红树莓果酒透光率为91.26%,与响应面预测值91.32%拟合性较好,且酒体澄清透明,酒香浓郁,稳定性好。     

壳聚糖的超声波降解及对芒果汁澄清效果的研究

以透光率为指标,以壳聚糖澄清和超声波澄清方法为对照,探讨经超声波降解的壳聚糖在不同功率、温度、作用时间和pH条件下对芒果汁澄清效果的影响。实验结果表明:经超声波降解的壳聚糖对芒果汁有较好的澄清效果,且明显优于未经降解的壳聚糖澄清对照组和单一的超声波澄清对照组,且分别在功率160W、温度50℃、作用时间30min、pH3.5条件下的透光率最高。     

红柠檬果汁澄清工艺的优化

选用红柠檬作为研究对象,以透光率为指标来研究果胶酶、复合酶、壳聚糖、膨润土和硅藻土这5种澄清剂对红柠檬汁的澄清效果,并探讨其中澄清效果较好的澄清剂对澄清后果汁品质的影响。通过单因素试验和Box-Behnken试验设计对红柠檬汁澄清工艺进行优化。结果表明,膨润土和硅藻土对红柠檬汁几乎没有澄清作用,果胶酶、复合酶和壳聚糖澄清效果都比较好。综合经济、方便和澄清后红柠檬汁品质3个方面考虑,最后选择果胶酶作为红柠檬汁的澄清剂。利用响应面优化试验得到了澄清型红柠檬汁的最优工艺,其条件为果胶酶用量0.22 g/100mL、处理温度50.3℃、pH 4.3和时间62 min,在此条件下,红柠檬汁透光率为93.8%。     

响应面法优化复合澄清剂对蓝莓果酒的澄清效果

利用壳聚糖、皂土、明胶和硅藻土4种澄清剂对蓝莓果酒进行澄清处理,将澄清效果较佳的壳聚糖与皂土以不同比例混合,对蓝莓果酒进行澄清处理。为优化壳聚糖-皂土复合澄清剂澄清的最佳工艺参数,在单因素试验基础上,选取复合澄清剂配比、水浴温度、水浴时间为自变量,以蓝莓果酒透光率为响应值,采用BoxBehnken中心组合试验和响应面分析法,研究自变量交互作用对蓝莓果酒澄清效果的影响,结果表明:复合澄清剂澄清蓝莓果酒的最佳工艺参数是:复合澄清剂比例2∶1、水浴温度50℃、水浴时间50 min,在此条件下蓝莓果酒的透光率为90.02%,与未经澄清相比提高了37.80%。此澄清条件对蓝莓果酒的理化成分无明显影响且稳定性有较大提高,酒体澄清透明,酸甜适口,风味浓郁。     

响应面法优化发酵青梅酒澄清工艺

以发酵青梅酒为研究对象,在单因素试验基础上,以壳聚糖添加量、pH值、澄清时间为自变量,透光率为响应值,通过Box- Behnken响应面法优化青梅酒澄清工艺。结果表明,最佳的发酵青梅酒澄清工艺为壳聚糖添加量15.5 g/L、澄清时间5 d、pH值为4.3。在此优化条件下,透光率达到97.4%。     

响应面法优化超声辅助凹土-壳聚糖澄清姜汁工艺

以凹土和壳聚糖为原料负载后作为复合澄清剂,在单因素实验的基础上,以姜汁透光率为考察指标,研究超声处理对姜汁澄清效果的影响,通过响应面法对姜汁澄清工艺进行优化,并以色泽、透光率、可溶性固形物含量、总酚含量、姜辣素含量、蛋白质含量为指标,对比了超声辅助凹土-壳聚糖澄清法与其他澄清方法对姜汁澄清效果及品质的影响。结果显示,超声辅助凹土-壳聚糖复合澄清剂澄清姜汁的最佳工艺条件为:超声时间10 min、超声温度54℃、超声功率160 W。在此优化条件下,姜汁的透光率达96.78%±0.56%以上。对比不同澄清方法发现,超声辅助凹土-壳聚糖澄清法所得澄清姜汁色泽浅、透光率高、姜辣素含量最高,且差异显著(P<0.05);而影响姜汁稳定性的总酚含量及蛋白质含量最低,与其它三种方法差异显著(P<0.05);可溶性固形物含量与其它方法相比差异性甚小。     

壳聚糖澄清草莓胡萝卜复合果蔬汁工艺研究

以壳聚糖为澄清剂,研究了壳聚糖添加量、果蔬汁溶液pH、澄清温度和时间对草莓胡萝卜复合果蔬汁的澄清效果。单因素试验显示:壳聚糖用量为0.25～0.4 g/L,复合果蔬汁pH为3.5～4.1,澄清温度为40℃～50℃,澄清时间为45 min～55 min时,复合果蔬汁的透光率和出汁率均达到峰值。通过正交试验获得的最佳工艺条件为:壳聚糖用量0.35 g/L,澄清时间为45 min,澄清温度为50℃,复合果蔬汁pH为4。验证试验显示此工艺条件处理的草莓胡萝卜复合果蔬汁透光率达到93.6%。     

柠檬凉茶澄清工艺研究

为优化柠檬凉茶的澄清工艺条件,以透光率为评价指标,比较了2种酶、2种澄清剂的澄清效果。通过单因素试验和二次回归正交旋转组合设计研究果胶酶添加量、壳聚糖添加量、澄清温度和澄清时间对柠檬凉茶透光率的影响,用DPS 7.05软件分析得到4个因素的回归方程。结果表明,酶和澄清剂复合使用比单一使用酶或澄清剂的澄清效果要好,同时确定了柠檬凉茶澄清工艺的最佳工艺条件为果胶酶添加量150 U/100 mL、1%壳聚糖添加量0.3 mL/100 mL、澄清温度45 ℃、澄清时间75 min,在该条件下柠檬凉茶透光率理论最大值为98.05%。通过试验验证,在实际情况下得到柠檬凉茶透光率为（97.98±0.10）%,说明模型预测值与实测值吻合性良好。     

沸石负载壳聚糖对高酸苹果发酵酒澄清工艺

以鲁加6 号苹果发酵酒为原料,根据Box-Behnkend 的中心组合试验设计原理,在单因素的基础上采用响应面分析法,建立沸石负载壳聚糖澄清苹果酒的二次多项数学模型,并以苹果酒澄清度为响应值和等高线建立响应面,研究沸石负载壳聚糖添加量、处理时间、处理温度对苹果酒澄清效果的影响。结果表明：沸石负载壳聚糖澄清苹果酒的最佳工艺条件为沸石- 壳聚糖澄清剂添加剂量11.6g/L、处理时间47.6min、处理温度27℃;与常规法澄清苹果酒相比,经过处理的苹果酒澄清度提高了16.8%,可溶性蛋白含量、总酚含量均有显著降低,而总酸、可溶性固形物含量、儿茶素、绿原酸、咖啡酸含量变化不明显,表儿茶素含量降低。     

壳聚糖澄清姜汁工艺条件的研究

用壳聚糖为澄清剂对姜汁进行澄清试验,研究了壳聚糖用量、温度、澄清时间、pH等工艺条件与姜汁透光率的关系.通过正交试验筛选出壳聚糖澄清姜汁的最佳工艺条件为:壳聚糖用量0.4 g/L、温度50℃、pH为6.0、反应时间40 min.澄清后,果汁透光率达98%以上,壳聚糖是一种有效的姜汁澄清剂.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the