甲酸类防霉剂对玉米的防霉效果及酒精发酵的影响

考察了甲酸类防霉剂LF2NC对含一定水分玉米的防霉效果以及对后续酒精发酵过程的影响。试验中的玉米取自于同一地区,经不同的烘干处理使其水分不同,投加不同量的防霉剂并在储存4个月后进行酒精发酵。结果表明,LF2 NC对玉米的防霉抑霉效果优于对玉米进行烘干处理,玉米水分为20%,LF2 NC添加量为7 kg/MT时,玉米储存4个月后内部未发生霉变。未添加防霉剂的玉米样品的酒精发酵效率高达94.7%,但防霉剂的使用对酵母酒精发酵过程产生了一定的抑制作用,在不同水分的玉米和不同的防霉剂投量下发酵效率降低了4.0%~4.9%。     

谷物辅料-在酿造中的应用和对啤酒质量的影响

在啤酒酿造中,经常使用辅料（没有发芽的大麦、小麦、大米或者高粱、玉米等,或是这些辅料的加工品）来替代部分麦芽.重要的是如何保证始产品质量,以满足市场消费者的需求.在本研究中,将对不同比例的玉米粉（10-20％）对于啤酒质量的影响进行分析和研究.对如下参数进行检测：麦汁色度、二甲基硫（DMS）和蛋白质含量、不可发酵性浸出物、发酵过程的降糖、酒精含量和啤酒的发酵度.当然,还要结合过滤的表现来进行综合性评价.这些样品（全麦芽啤酒,玉米淀粉占比10％-20％的啤酒）均来自商业化的啤酒生产公司（3000hl发酵罐）.实际上,当采用了10-20％的玉米淀粉作为辅料时,对麦汁的色度有影响,这个影响当然相对较轻微（分别是11.1和11.5EBC）,而全麦芽啤酒的色度是12.2EBC.采用非发芽谷物作为辅料所生产的啤酒在游离氨基氮水平、DMS和非发酵性浸出物的含量方面都相对全麦芽啤酒要低一些.同时,在酒精含量和发酵度上又相对较高.但是对于最终的啤酒产品而言,这种影响显得并不十分明显.     

两段法发酵雪莲果果醋饮料的研究

以雪莲果为主要原料在20 L发酵罐中进行液态发酵,通过酒精发酵和醋酸发酵两个阶段过程进行单因素试验和正交试验.实验表明,在酒精生成阶段,当糖含量为16 g/dL,接种量8％,发酵温度31℃,发酵时间120 h时产生的酒精浓度最高.醋酸生产优化工艺为:酒精度为10％,醋酸杆菌种龄为54 h,接种量为5％,发酵时间120 h时,醋酸产量最高.     

应用浓醪发酵技术推动酒精行业科学发展

高浓度酒精发酵始于20世纪70年代,主要以可再生资源粮食或植物纤维为原料,采用连续发酵,最终酒精浓度可达16％(v／v)左右,实验室小麦粉高浓发酵可达21％(v／v),淀粉利用率达90％以上,发酵时间在50～70h。在蒸煮工艺方面对低温蒸煮、中温蒸煮及生料发酵作了探索。浓醪发酵的料水比为1：2．8～3．2。安琪酵母股份有限公司研究开发的安琪超级耐高温酿酒高活性干酵母已形成生产力,并投入大生产使用,其发酵结束时醪液的酒精浓度可达到14％～17％(v／v)。国内外在实验室筛选分离的酒精酵母,有的产酒精浓度可达20％(v／v)左右,但大都尚未形成生产力。酒精浓醪发酵技术是一个方向,对生产企业提高效益,节约能源,保护环境将有积极的促进作用。应以科学发展观为指导,大胆采用酒精浓醪发酵技术,大力推进酒精行业的科技进步,促进酒精产业的健康发展。     

酒精浓醪发酵联产乳酸化饲料新工艺

以玉米为原料,耐高温耐高酒精度的活性干酵母为发酵剂进行浓醪酒精发酵实验,对糖化发酵工艺过程中酒精度、总糖、还原糖、酸度以及CO2失重等指标的过程变化进行了研究.并利用一株嗜酸乳酸杆菌,以酒糟为基质进行酒糟混合料的乳酸发酵实验.结果表明玉米原料经酒精浓醪发酵60 h后,玉米发酵醪中酒精体积分数达12.8%,残总糖质量分数为3.46%,残还原糖质量分数为0.19%,淀粉利用率89.88%以上.酒糟混合料接种乳酸菌,33 ℃条件下发酵15 d,发酵后酒糟混合料水分质量分数为53%,粗蛋白质量分数18.62%,粗脂肪质量分数3.32%,粗纤维质量分数3.95%,17种氨基酸质量分数达18.3%;乳酸质量分数1.93%,每克酒糟发酵料含乳酸菌菌数为4.2×107个,达到所设计乳酸菌菌数的要求.     

木聚糖酶在玉米原料酒精发酵中的应用研究

探讨了木聚糖酶对玉米原料酒精发酵的影响.经优化后木聚糖酶的最适使用工艺为:木聚糖酶在发酵开始时加入,添加量为170U/g,料水比为1:2.5,初始pH值为自然.与对照组相比,原料出酒率提高5.93%,发酵周期缩短了12h,表明木聚糖酶对玉米原料酒精发酵有明显的促进作用.     

不同液化酶对玉米和小麦为原料的酒精发酵影响

目前许多酒精生产企业使用玉米和小麦混合原料生产酒精,小麦投加最高比例已达到20%。以玉米和小麦混合原料为基础,对不同厂家液化酶进行酒精发酵对比试验,通过检测分析,选择性能更好的液化酶为大生产服务。     

耐高温酒精活性干酵母的研制和应用——Ⅱ.耐高温酒精活性干酵母在酒精及白酒发酵中的应用

本文在前报获得耐高温酒精活性干酵母(ADY)的基础上,(1)进行了主发酵温度为高温40℃的酒精发酵试验,发酵动力学曲线显示,耐高温酒精ADY在主发酵温度40℃条件下,仍具优良的发酵性能,节水节电,适于安全度夏。对玉米、大米、薯干等不同原料均具良好的适应性。(2)在浓香、清香、兼香等香型的大曲酒以及小曲酒工艺中进行了耐高温酒精ADY的应用试验,结果表明,应用方法适当,在维持风味不变的前提下,能提高出酒率10～20％,并对其质量稳定有所帮助。     

玉米原料超高浓度酒精发酵

以全磨玉米为原料,研究了超高浓度条件下传统工艺与生料工艺的黏度变化。采用传统工艺,在超高浓度条件下,物料的糊化、液化会变得非常困难。而采用生料工艺,黏度始终维持在合理的水平。对高浓度传统工艺和生料工艺发酵的结果进行对比,证明生料工艺可以产出更多的酒精;对超高底物浓度(35%绝对干物)生料发酵时采用温度梯度控制,使用市售酒精干酵母,在98 h内发酵醪液酒精浓度可达20%以上。     

应用植酸酶提高玉米酒精出酒率的研究

探讨了在玉米原料酒精发酵醪中添加植酸酶对酒精发酵的影响。在玉米原料酒精发酵醪中添加15u／g原料的微生物植酸酶，发酵成熟醪中酒精分和磷含量可达10．10％(v／v)和518．84μM，分别比对照提高5．54％和8．31％；原料出酒率可达39．81％，比对照提高6．96％。     

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