北方大曲酱香酒云门陈酿高温堆积发酵工艺探讨

随着大曲酱香白酒生产轮次的增加,含水量逐步增大,堆积糟醅疏松性差,采用堆积底部铺垫稻皮20cm以上,外接不锈钢通风管的方法,适当增加堆积糟醅堆底部含氧量,能有效提高堆积糟醅"大回酒"堆底和堆芯升温幅度,对提高"大回酒"出酒率和质量有一定作用。     

接堆方式对酱香型白酒酒醅发酵质量的影响

为探索酱香型白酒一、二轮次中接堆方式对酱香型白酒酒醅堆积发酵质量的影响,从酒醅微生物、酒醅升温情况、堆积发酵时间、酒醅感官香气等方面,对酱香型白酒生产过程中"逐排添加""、齿轮型""、均撒式""、毡松式"四种接堆方式进行了分析研究。结果表明",均撒式"接堆方式操作的发酵堆酒醅微生物生长情况、堆积发酵质量优于其他三种接堆方式,说明"均撒式"接堆方式更有利于酒醅堆积发酵,有利于基酒产量质量提升。     

破堆移位解决酱香酒冬季堆积发酵异常研究

通过对一、二轮次堆积发酵中异常发酵堆A进行破堆移位处理,以同一车间正常堆积发酵酒醅B为对照,研究酒醅中发酵微生物及理化指标变化规律,分析破堆移位对入库酒产量、质量影响的相关性。试验结果表明:破堆移位处理能使异常堆恢复正常升温、降低酒醅的总酸与水分含量,并显著增加二轮次酒醅中还原糖含量;该处理对堆积酒醅中好氧细菌如芽孢杆菌的生长有显著促进作用,并显著减少乳酸杆菌的含量,绝大部分优势真菌在破堆移位处理后含量均有所增加;该处理保证了酒的质量和产量,且能显著增加二轮次酒的产量。研究结果表明"破堆移位"在生产中可以有效解决气温较低环境下出现的堆积发酵异常现象。     

酱香型白酒下沙、造沙轮次堆积发酵过程中酒醅温度与微生物的变化规律分析

本文以酱香型白酒下沙、造沙轮次堆积发酵酒醅为研究对象,分析了堆积过程不同位置和时间的酒醅温度与微生物变化规律及其相互关系。结果表明,堆积发酵酒醅温度由内向外逐渐升高,表层酒醅温度变化呈"S"型曲线,其升温幅度高于内部酒醅;而堆子顶部与中部升温幅度高于底部。堆积发酵初期细菌数量高于酵母菌,经堆积发酵细菌与酵母菌的数量逐渐增加,至入窖前细菌和酵母菌数量均达到10^7~10^8CFU/g酒醅。酒醅温度升高会延迟微生物数量的增加,说明微生物的生长繁殖对堆积温度的升高有促进作用;而当酒醅温度超过50℃后,细菌和酵母菌数量均有降低。     

堆积糖化方式对酱香型白酒生产的影响

堆积糖化是酱香型白酒酿造非常独特和关键的工序,堆积糖化质量直接影响窖内发酵结果,决定着原酒出酒率和品质。本文通过对比研究"平顶式"和"尖顶式"堆积糖化方式对糖化堆温度、酒醅微生物群系和理化指标以及产质的相关影响生产实验,探索不同堆积糖化方式对酱香型白酒生产的影响。实验发现,当糖化堆采用"平顶式"堆积糖化方式时,糖化堆酒醅升温幅度略高,糖化堆酒醅主要酿酒微生物数量较优,入窖酒醅还原糖含量相对更大,原酒出酒率与优级品率均较优。     

浅析酱香型白酒堆积发酵中酒醅倒堆试验的应用

高温堆积,可以实现二次制曲,网罗和富集空气中的酵母菌,优化并驯化耐高温酵母的耐受性,提高酶活性。酒醅倒堆,可使堆积酒醅进一步与氧气接触,有效地改善堆积酒醅中芽泡杆菌和酵母菌在各位点的平衡,促进堆积酒醅糖化,发酵的一致性。     

“FD工艺”对酱香型白酒堆积过程的影响

为探究酱香型白酒酿造堆积过程中酒醅堆各位点发酵状态及细菌群落结构的变化规律,将“FD工艺”应用于酱香型白酒第二轮次酒生产堆积发酵过程,对堆积过程中的酒醅理化因子和细菌群落变化进行探索和研究。结果表明:相较于传统酒醅堆积发酵而言,“FD工艺”处理后的酒醅酸度能够有效降低,酸度下降了1.72 mmol/10 g,同时能有效控制酒醅中水分含量,使水分含量保持在±0.8%;“FD工艺”能有效促进淀粉转化（增加转化了0.76%）,同时酒醅中还原糖含量也增加（增长了0.46%）;酒醅细菌群落Shannon指数、Sobs指数和Ace指数显著（P<0.05）增加;“FD工艺”处理后的酒醅微生物属分类水平的丰富度和多样性明显增加,有利于好氧菌属如芽孢杆菌属Bacillus、高温放线菌属Thermoactinomyces等微生物生长。综上,“FD工艺”能改善堆积发酵过程中酒醅发酵不均的情况,酒醅细菌群落丰富度和多样性均明显增加,有利于优势好氧及耐高温细菌群落的生长。     

酱香型酒糟醅堆积过程温度和微生物区系变化及其规律性

研究了酱香型酒糟醅堆积过程温度和微生物区系的变化动态.结果表明:①通过堆积,糟醅堆表40 cm厚的堆表层温度有较大幅度上升,一般可达50℃左右,堆心温度一直处于缓慢升温状态,但升温幅度远低于堆表层;②堆积过程中,糟醅的酵母菌类和非芽孢细菌类数量有较大幅度增长,芽孢细菌类仅略有增长,而霉菌类数量极少且呈下降趋势,未发现放线茵类生长;③堆积终了时,酵母和细菌数量约占总数的95%以上,表层酵母菌占总数的70%以上,细菌占总数的10%～25%,维心酵母菌和细菌各占总数的比例轮次间差异较大;④堆积工序对酱香物质的生成及酒精发酵都十分重要,在生产上要加强对堆积的生产管理,严格控制堆积时间与温度.     

口子窖酒糟醅堆积与窖内发酵工艺初探

为探索口子窖酒生产中堆积和窖内发酵工艺的基本规律,对糟醅进行温度与微生物跟踪检测,与相应出酒率对比分析。结果表明,堆积期间,前期升温缓慢、后期升温加快,堆芯升幅小,堆边升幅大;不同位置的各种微生物有不同生长趋势。窖内发酵,不同位置的温度变化趋势不同;各层微生物变化趋势差异较小。窖池酒醅蒸馏后出酒率与入窖后糟醅中酵母菌总数有正相关趋势。     

习酒浓香型制酒糟醅接种探讨

浓香型白酒生产中,入窖糟醅正常升温规律为"前缓、中挺、后缓落"。但是在母糟活力差、环境气温低等条件下,会引起入窖糟醅无法正常升温。具体表现为升温幅度小、顶温不高、升温慢或不升温现象。因主发酵期糟醅未能正常升温,糟醅中的淀粉得不到充分利用,直接影响排次酒的产量和质量。针对这一现象我们借鉴酱香的堆积升温的原理,将小部分入窖糟醅进行堆积发酵,自然网罗微生物,待堆积顶温达到要求时,与入窖糟醅进行拌和后入窖发酵,目的是同酱香堆积一样起到"二次制曲"的作用。     

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.     

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.     

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 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.     

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.