原料大麦和麦芽中霉菌污染的检测

目前,国内大多数啤酒厂尚未开展对原料的微生物检测,随着啤酒生产的发展,对这方面的工作应加以重视并逐步建立相应检测制度。 1 原料大麦和麦芽中霉菌污染的危害 大麦上霉菌的数量不多时,对啤酒酿造没有影响。如果收获或贮存时水分较高,这些微生物会迅速繁殖,产生严重的后果。首先,霉菌会使贮存的大麦颗粒发热,如灰绿曲霉、亮白曲霉和黄曲霉,能使贮存大麦的温度升高到55℃,能在此温度下维持数星期。这样,为耐热的细菌生长繁殖提供了条件,严重时可     

浅谈大麦与麦芽的霉菌及其危害

本文介绍了霉菌对大麦及麦芽的感染和危害。     

不同品种大麦与麦芽霉菌含量的初步研究

啤酒生产过程中对微生物已有比较详细的研究，但对大麦和麦芽微生物的讨论相对较少。其中最常见的曲霉和青霉属的霉菌，对大麦造成的破坏较大，它通过侵蚀胚乳，使大麦丧失活力。大麦在储存和制麦过程中霉菌的变化情况，不仅对麦芽质量有影响，而且它也影响啤酒生产，最终影响啤酒的气     

澳大利亚大麦生产工艺探讨

为保证产品质量,我们每年都购进一批进口大麦,主要是以澳大利亚大麦为主,由于采购产地不同,虽然同为澳大利亚大麦,但其品种,特性不同,要想达到优级标准,就要求采用不同的制麦工艺。如果工艺不适合,生产出来的麦芽就达不到要求。西澳大利亚大麦,其特点是吸水慢,...     

西澳Stirling大麦制麦特性的探讨

本文总结了该公司的几年西澳Ｓｔｉｒｌｉｎｇ大麦的质量及其生产情况,探讨该种大麦的一些特性。     

啤酒麦芽的霉菌及毒性评价

本文对属于1~3级质量标准的啤酒麦芽25份(S麦芽厂9份,其他厂家16份)进行了霉菌菌相分析;霉菌毒素测定;对有关的麦芽和菌株进行了生物毒性测定。结果:在HCA培养基上,S麦芽厂的麦芽,霉菌菌落数平均是5.69logCFU/g,菌相组成以棒曲霉为绝对优势菌,次为黄曲霉,毛霉、灰绿曲霉等;麦芽内部霉菌检出率,有的最高达100%,MFI值最高达3.34。其他厂家生产的麦芽,霉菌菌落数平均是3．55 logCFU/g,菌相组成以毛霉为优势菌,次为交链孢霉,灰绿曲霉,纯绿青霉,黄曲霉,圆弧青霉等。对麦芽进行了AFB_1测定,有的麦芽AFB_1含量达1600ppb,对分离的黄曲霉进行了APA产毒株筛选,29株菌上4株能产生AFT。对1份棒曲霉污染严重的麦芽进行小白鼠急性毒性试验,3只小白鼠死亡1只(IP),死亡前有爪行不稳,左右发抖等神经症状出现。棒曲霉的产毒培养物的毒性,8只小白鼠5只死亡(IP),死亡前症状与以上麦芽相同。全部25份麦芽按目前质量标准,可以正常用于啤酒酿造。很明显现在使用的麦芽质量标准没有充分注意到霉菌的污染及由此引起的卫生质量问题。     

污染物赭曲霉素在大麦、麦芽、啤酒中的测量

利用ELISA(RIDASCREEN)方法研究大麦、麦芽、啤酒样品中存在的赭曲霉素A(OTA)。OTA的检测限很低，啤酒是0．08μg／L、大麦和麦芽是0．4μg／L。在29种大麦样品中有26种OTA含量是在0．53～12μg／kg之间。在24种麦芽样品中有23种OTA含量在0．5～6．6μg／kg之间，仅有一种麦芽样品没有检出OTA。在150种啤酒样品中有42种OTA含量在0．1～8．10μg／L之间(占28％)，108种啤酒样品(占72％)没有发现OTA，仅有一种啤酒样品OTA含量高于5μg／L。     

世界啤酒,大麦及麦芽产业的发展

世界啤酒、大麦及麦芽产业的发展张沛（青岛啤酒集团有限公司科研中心；２６６１００）啤酒作为含酒精量最低的饮料酒，由于其营养丰富且价廉物美已受到越来越多消费者的喜爱，目前除伊期兰国家外，世界各国均生产和销售啤酒，特别是在发展中国家，啤酒生产更是得到迅猛发...     

Genotypic and environmental variation in phytic acid content and its relation to protein content and malt quality in barley

Phytic acid or phytate is a chelating agent, which is involved in binding minerals (such as K⁺, Ca²⁺, Zn²⁺, Fe²⁺, etc.) and making them unavailable for dietary absorption. It is also involved in forming complexes with protein, making protein less soluble, and affecting enzymatic degradation, gastric absorption, and malting processes. The phytic acid and protein contents of barley grains are influenced by genetic and environmental factors. This study investigated differences in phytic acid and protein contents in grains of 100 barley (Hordeum vulgare L.) genotypes or cultivars. Eight barley cultivars were selected and grown at seven locations for two years to study the effects of genotypic and environmental factors on phytic acid content (PAC) and its relation to malt quality. The phytic acid contents of 100 barley genotypes ranged from 3.85 mg g⁻¹ to 9.85 mg g⁻¹, with a mean of 7.01 mg g⁻¹. The effects of cultivars, locations, time and their interactions were highly significant, but the variation was mainly attributed to the environment (location and time). The correlation between grains phytic acid and protein content was significant and positive. Whereas, the correlation between grain phytic acid content and malt extract was significant and negative. The relationship between phytic acid and protein contents of barley is important as it affects the malting process, malt yield and quality, and final beer quality. Barley grain for malting and feed uses should have low phytic acid content.     

Metabolite profiling of barley: Influence of the malting process

A metabolite profiling approach based on gas chromatography–mass spectrometry (GC/MS) was used to investigate time-dependent metabolic changes in the course of the malting process of barley. Barley grains were subjected to a micro-malting procedure involving steeping, germination and kiln-drying. Samples taken in the course of the malting process were subjected to an extraction and fractionation procedure covering a broad spectrum of lipophilic (e.g. fatty acid methyl esters, hydrocarbons, fatty alcohols, sterols) and hydrophilic (e.g. sugars, acids, amino acids, amines) low molecular weight barley constituents. Investigation of the obtained fractions by GC resulted in the detection of 587 distinct peaks of which 173 were identified by means of MS. Statistical assessment of the data via principal component analysis demonstrated that the metabolic changes during the malting progress are reflected by time-dependent shifts of the scores. Analysis of the corresponding loadings showed that polar metabolites were the major contributors to the malting time-driven changes in the metabolic profiles. Quantifications based on standardised peak heights revealed dynamic changes of the metabolites in the course of the different malting stages.     

Residue levels of malathion and fenitrothion and their metabolites in postharvest treated barley during storage and malting

In order to investigate residue levels of malathion and fenitrothion and their metabolites (malaoxon, isomalathion and fenitrooxon) during storage and malting, pesticide-free barley was treated with these insecticides. Barley was placed in a sealed plastic container and treated with a dust of malathion (2%). Fenitrothion emulsion (41.6% wettable powder) was applied onto the walls of a small-scale storage vessel. Residues were determined in barley at about 1-month intervals during storage and in malt produced from the barley stored at various times. The analysis of the residues was carried out by GC equipped with a nitrogen-phosphorus detector (NPD). Although the approved doses of insecticides for stored grain were used, the residue levels exceeded the maximum residue limits (MRLs) at the beginning of storage. While the degradation of malathion and isomalathion in barley was observed to be about 65–72% during the storage period, the malaoxon was degraded extensively (85%). A significant percentage of fenitrothion residues (80%) were dissipated from grains for the short-term storage probably because of hot weather conditions. In malt, rates of degradation and volatilisation of the residues increased by the heat involved in malting. The carryover of the residues from barley into malt was also found to be dependent on the log P_ow (partition coefficient between n-octanol and water) values of the insecticides.     

Influence of phenolics in finger millet on grain and malt fungal load,and malt quality

Phenolic type, fungal load, germinative energy (GE) and malt quality of finger millet grain types of varied kernel colour and phenolic content were analysed, to determine if phenolics in finger millet grain influence its malt quality. The fungal load (total fungal count (TFC) and infection levels) of the unmalted grain and malt were negatively correlated (p < 0.05) with total phenolics (TP) and amount of phenolic type (condensed tannins, anthocyanins and flavan-4-ols). High-phenol finger millet types had much higher malt quality than the low-phenol types, with respect to diastatic power (DP), and α- and β-amylase activities. GE, DP and α-amylase activity were positively correlated with TP and amount of phenolic type (p < 0.05) and negatively correlated with TFC (p < 0.01). Phenolics in finger millet grain influence its malt quality positively by contributing to attenuation of the fungal load on the germinating grain.     

Changes in malt quality during production in two commercial malt houses

This investigation presents a holistic and comprehensive assessment of the stepwise changes in barley quality during the malting process for multiple batches of two Australian malting varieties (Buloke and Gairdner), in two modern, commercial scale pneumatic malthouses. The study sought to analyse and compare malting plant and variety with respect to basic changes in malt quality for protein (total protein and free amino nitrogen), fermentability (apparent attenuation limit and diastatic power), extract yield, along with filtration indicators (lautering efficiency, viscosity and β-glucan). Overall, comparing the two malt plants, it was observed that although malt batches and varieties followed different malting pathways, the finished and kilned malt  was of satisfactory quality in terms of FAN, viscosity, friability, fermentability and extract. © 2020 The Institute of Brewing & Distilling     

以未发芽大麦替代麦芽酿造啤酒及其麦香改善研究

本文研究了利用酶制剂Ondea Pro进行大麦啤酒的生产,对其麦汁糖谱、氨基酸谱、蛋白质区分、α-氨基氮和大麦啤酒理化成分及风味物质等指标进行了检测,特别是对麦香物质呋喃酮、2-乙酰吡咯、2-乙酰-1-吡咯啉、麦芽酚、2-甲基吡嗪、乙基吡嗪、乙酰呋喃和甲基糠醛等化合物进行了分析,并邀请专业品酒委员进行了感官品评。研究结果发现,利用Ondea Pro酶生产的麦汁,能够满足酵母发酵需求,然而大麦啤酒存在明显的麦香缺陷。通过额外添加不同比例的焦香麦芽,分析大麦啤酒中主要麦香物质的变化规律,结合感官品评,结果表明添加1%的焦香麦芽酿造而成的大麦啤酒,其主要麦香物质和品评口感与麦芽啤酒接近。添加少量焦香麦芽生产的大麦啤酒市场潜力具大,极具推广价值。      

Influence of malt browning degree on lipoxygenase activity

The development of off-flavour in pale beer is generally attributed to the oxidation of the intermediate products of lipid degradation catalysed by lipoxygenase during mashing. This paper deals with the effect of speciality malts, having different browning levels, on malt lipoxygenase. The results obtained showed that lipoxygenase activity, which was found to be present only in the pale malt, was affected by mashing temperatures above 63 °C and by the presence of Maillard reaction products in the speciality malts. In particular, the addition to pale malt of speciality malts, having high inhibitory capacity towards lipoxygenase but low colouring potential, was effective in reducing the off-flavour development in pale beer.     

霉菌对麦芽品质影响的研究

麦芽是啤酒酿造的主要原料,其表面附着了各类微生物,尤其是受霉菌侵染的麦芽可能引起β-葡聚糖、可溶氮和麦汁黏度升高等问题。本文研究了三种大麦在制麦过程中添加已筛选的大麦自身携带的四种霉菌对麦芽质量的影响,发现链格孢霉和镰孢霉对大麦细胞壁降解和细胞内基质溶解有明显的负作用,导致β-葡聚糖酶活力降低,β-葡聚糖含量增加,麦汁的浊度升高;其中镰孢霉对Gairdner的麦汁浊度影响最大,增加220%;添加镰孢霉的三种麦芽中蛋白酶活力和库值都有所降低,其中国产内蒙麦芽库值下降最多,下降了7.2%。      

小麦麦芽替代大麦麦芽生产啤酒的工艺探讨

在我国的啤酒生产中,一般是以大麦麦芽为主要原料。但目前所用的进口大麦麦芽价格约为2700元/t,国产大麦麦芽价格也在2300元/t左右,均比前一二年有了较大的提高,从而导致啤酒产品的生产成本加大,企业盈利水平下降。并且,啤酒市场竞争激烈,产品雷同现象比较普遍。如何降低生产成本,开发新产品,提高市场竞争力,增强企业效益是当前我国众多啤酒生产厂家积极努力解决的问题。而用小麦麦芽替代部分大麦麦芽生产啤酒则可以在一定程度上满足上述需求,为此,本文拟对此产品的工艺情况作一探讨。一、小麦麦芽概述小麦麦芽是以小麦为原料生产的,小麦的…