大麦品种和制麦过程对麦芽含脂量的影响

脂类物质影响啤酒泡沫稳定性并对啤酒老化有重要作用.啤酒中脂类物质的浓度和性质取决于原料的组成和酿造过程.本文研究了大麦品种和制麦过程对麦芽含脂量的影响.采用意大利的四种春大麦和一种冬大麦作为样品,进行微型制麦和分析.本研究旨在确认大麦品种对麦芽含脂量及制麦过程中脂肪酸（FA）含量变化的影响.采用主成分分析（PCA）建立不同样品之间的关系,同样也对大麦的含脂量和制得麦芽品质的相关性进行了评估.数据显示制麦过程中大麦转化为麦芽时总脂含量显著下降;不同大麦品种的脂肪酸含量和脂肪酸图谱均不同.大麦含脂量和制得麦芽质量的相关性确认了脂类的负面影响.     

制麦过程大麦和麦芽中麦角甾醇和呕吐毒素含量的变化

本文测定了不同品种大麦和麦芽中的呕吐毒素和麦角甾醇含量,共分析了20个大麦和20个麦芽样品,用正己烷溶解谷物中的碱性水解提取物以获得麦角甾醇,用乙腈/水及固相萃取(SPE)法提取呕吐毒素,通过配有紫外检测器的高效液相色谱(麦角甾醇)和质谱(呕吐毒素)进行检测。分析了制麦过程对两种化合物的影响,其中大麦中麦角甾醇浓度为0.88～15.87mg/kg,麦芽中的浓度为2.63～34.96mg/kg,比制麦增加了95%。因此,制麦过程对麦角甾醇浓度的影响很大(P=0.07);同时发现大麦中呕吐毒素浓度最大为641μg/kg,麦芽中为499μg/kg,没有发现制麦过程对呕吐毒素生成有影响,而且麦角甾醇和呕吐毒素间的相关性非常低(大麦为0.02,麦芽为0.01),因此麦角甾醇含量不能作为呕吐毒素污染的一个指标。     

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.     

小麦麦芽制麦过程中酸感物质的变化

为了能够更好地了解小麦麦芽在不同制麦阶段酸感物质的变化,为小麦麦芽制麦工艺的优化提供技术参考,本研究选取琥珀酸、乙酸、柠檬酸、苹果酸和乳酸作为酸感物质的代表,按照微型制麦工艺对样品进行制麦操作,采用高效液相色谱~（HPLC）对不同制麦时间的酸感物质进行检测分析,结果发现：小麦在发芽期间,总酸感物质含量逐渐升高;苹果酸在整个制麦过程一直处于动态平衡过程中;乙酸、乳酸、柠檬酸和琥珀酸都随时间逐渐升高,较小麦分别增加了11．2倍、6．1倍、7．0倍、4．7倍,且都在发芽阶段时大量增加。     

四氢嘧啶对澳麦Gairdner和国麦甘啤3号制麦过程的影响

四氢嘧啶作为一种酶保护剂,首次被应用于澳麦Gairdner和甘啤3号制麦过程中。通过在2种大麦制麦工艺中添加四氢嘧啶,与未添加四氢嘧啶的工艺进行比较,研究结果表明两种大麦发芽后绿麦芽中淀粉酶、β-葡聚糖酶、纤维素酶经过高温干燥过程酶活性均有不同程度的损失,而四氢嘧啶对这3种酶的热稳定性起到保护作用,同时对制麦过程其他物质变化未产生不良影响。对2种工艺制备的麦芽进行理化指标分析,结果对比表明:采用添加四氢嘧啶工艺制备的麦芽具有更好的酿造性能。     

小麦芽脂肪酶酶学性质以及制麦过程的酶活变化

以对硝基苯酚丁酸酯为底物,确定了小麦芽脂肪酶的酶学性质:最适温度为37℃;最适pH为8.0;4～35℃脂肪酶的热稳定性较好,35℃下保温60 min后其活力仍可保持在88.37%,45℃保温60 min后其活力保持在46.81%,55℃保温60 min酶失活;pH5.5～6.0范围内对脂肪酶的破坏力相对较小,保温60 min其活力仍可分别保持在95.11%和91.11%;Fe3+对脂肪酶有较强的抑制作用;Cu2+、Mn2+、Al3+对脂肪酶的抑制作用较小;Ca2+、EDTA对脂肪酶有较强的激活作用。小麦制麦过程中发芽第4天酶活达到最大值,为8.52 u/g,随后酶活下降;干燥会破坏部分脂肪酶的酶活,损失率为27.06%。小麦芽籽粒、胚芽、胚根中的脂肪酶酶活依次降低,分别为8.01 u/g、7.55 u/g、6.83 u/g;协定法麦汁糖化过程中,无胚芽麦芽脂肪酶的酶活比有胚芽的低,且酶的失活速度也比较大,在55 min(70℃)时,脂肪酶完全失活。     

Influence of barley malting operating parameters on T-2 and HT-2 toxinogenesis of Fusarium langsethiae,a worrying contaminant of malting barley in Europe

The fungus Fusarium langsethiae, exclusively described in Europe at present, seems to have taken the place of other Fusarium species in barley fields over the last 5 years. It has proved to be a highly toxic type-A trichothecene producer (T-2 and HT-2 toxins). The aim of this work was to study the ecotoxinogenesis of this fungus the better to identify and manage the health risk it may pose during the beer manufacturing process. The influence of temperature and water activity on its growth rate and production of toxins are particularly assessed from a macroscopic point of view. Different cultures were grown on sterilized rehydrated barley with a water activity between 0.630 and 0.997 and a temperature ranging from 5 to 35°C. Biomass specific to F. langsethiae and T-2 and HT-2 toxins were quantified by real-time polymerase chain reaction and liquid chromatography-mass spectrometry, respectively. It appears that the optimal temperature and water activity for F. langsethiae toxinogenesis are 28°C and 0.997. This fungus was able to produce 2.22 g kg^?1 of these toxins in 16 days on barley in optimal production conditions. The malting process seems to be a critical step because, in its temperature range, specific production was six times higher than under optimal temperatures for fungus growth. In the short-term, this work will help redefine the process conditions for malting. In the medium-term, the results will contribute to the development of a molecular tool to diagnose the presence of this contaminant and the detection of the toxins in barley, from fields to the end product.     

影响麦芽溶解度的关键制麦参数及参数优化

麦芽溶解度是衡量麦芽酿造性能的重要指标,针对影响该指标的关键制麦参数即浸麦度、发芽温度、凋萎温度、干燥温度,以进口大麦为原料,进行了单因素试验,并分别采用荧光染色法和冷场发射扫描电子显微镜观察麦芽胚乳溶解情况来确定麦芽溶解度。并在此基础上采用响应面设计优化制麦工艺。结果表明,各因素对麦芽溶解度影响程度的大小顺序为B(发芽温度)D(干燥温度)C(凋萎温度)A(浸麦度)。优化制麦工艺条件为:浸麦度为46%,发芽温度为16℃,凋萎温度为48℃,干燥温度为78℃。优化制麦工艺后,麦芽溶解度从81%提高到87%。     

Monitoring of malting process by characterization of glycation of barley protein Z

Glycation is a common form of non-enzymatic modification that influences the properties of proteins. Although occurrence of protein glycation in food is known for several years, qualitative and quantitative analysis of its reaction products is still a challenging task. Our attention was focused on monitoring of changes in the glycation degree of protein Z, one of the most important protein components of barley malt that influences the properties of beer. The modification during the malting period was studied by a combination of gel electrophoresis, liquid chromatography and mass spectrometry. Water soluble proteins were extracted from barley grains at different times of malting and separated by gel electrophoresis. Protein Z was clearly identified in the band at a position of about 43 kDa and further studied by MS with matrix-assisted laser desorption/ionization technique in detail. From the analysis, we found that protein Z glycation is detectable from the second day of malting. The glycated peptide was observed as a weak signal of m/z 2,619 in the MS spectrum. To confirm the presence of glycation, the MS/MS experiments of both unmodified (m/z 2,457) and modified peptides (m/z 2,619) were carried out. We successfully established a procedure based on the monitoring of glycated peptides in positive reflectron mode to monitor the progress of malting using protein Z as a model protein that might be a potential marker reflecting this technological process. We also demonstrated the high suitability of MS/MS analyses to provide more structural information on peptide modifications.     

制麦工艺对麦芽中DPPH·清除率影响

优化了DPPH·清除率检测方法的条件,包括麦汁稀释倍数、反应温度和反应时间,并考察了制麦工艺对麦芽DPPH·清除率的影响。发现适当地延长干浸时间,在降温的方式下发芽对水敏感性大麦DPPH·清除率有一定的提高作用,且其焙焦温度对其影响相对较大。     

贮存条件对Gairdner大麦和麦芽的醛类物质的影响

利用固相微萃取与气相色谱-质谱联用检测醛类物质的方法跟踪了啤酒酿造大麦和麦芽Gairdner中的脂质氧化醛、Strecker醛、糠醛在10℃和35℃条件下的变化趋势。新鲜麦芽中的Strecker醛和糠醛含量高于大麦,而脂肪氧化醛含量和脂合氧化酶活力明显低于大麦。大麦和麦芽中脂质氧化醛和糠醛在贮存过程明显增加,具有指示大麦和麦芽新鲜度的可能性。10℃和35℃贮存5个月后,大麦的反-2-壬烯醛分别增加了1.01和1.62倍,而麦芽的反-2-壬烯醛分别增加5.12和17.74倍。由于反-2-壬烯醛的高风味活性特点,建议将反-2-壬烯醛作为大麦和麦芽新鲜度与品质优劣的关键性评价指标。本研究从脂质氧化醛等指标量化的角度,再次肯定了低温贮存相对于高温贮存更利于大麦和麦芽保持新鲜的事实。     

大麦麦芽阿拉伯木聚糖的研究进展

随着纯生啤酒等高端啤酒产量的增加,啤酒生产对影响黏度和过滤速度的大分子物质含量的要求越来越高。阿拉伯木聚糖是组成大麦胚乳细胞壁的主要非淀粉多糖之一,能够形成高黏度的溶液,影响麦汁和啤酒的黏度和过滤速度。文中从结构、含量的检测、降解及研究展望等方面分析了大麦麦芽阿拉伯木聚糖的研究现状,指出了存在的问题。建立准确的高分子量阿拉伯木聚糖检测方法,研究不同分子量的阿拉伯木聚糖含量对黏度和过滤速度的影响,研究大麦麦芽的内源木聚糖酶抑制剂对阿拉伯木聚糖降解的影响以及高效降解阿拉伯木聚糖的酶制剂配方是今后的发展方向。     

啤酒大麦抗氧化力评价的研究

啤酒的风味稳定性是酿造者所面临的最大技术挑战,也是酿造高质量啤酒所必须解决的难题,而提高啤酒本身的抗氧化力,尤其是啤酒原料的抗氧化力则可能是解决啤酒风味稳定性的一个行之有效的途径。本文阐明了提取溶剂对大麦抗氧化力评价的影响,并系统研究了不同的提取溶剂对大麦中游离酚类化合物的提取能力和选择性。基于以上的研究,将80％丙酮作为评价啤酒大麦抗氧化力的提取溶剂。利用主成分分析法对不同品种的啤酒大麦进行了抗氧化力的分类,运用构建的抗氧化力综合评价指标对16个大麦品种的20个样品进行了排序。     

Influence of malting on selected components of soya bean,black bean,chickpea and barley

The influence of malting for 24 and 48 h on selected components was studied in soya bean, black bean, chick pea and barley. Proximate composition, calcium, iron zinc, α-galactosides including ciceritol, sucrose, phytic acid, myo-inositols phosphate and lectins were determined. The malting conditions were adequate to maintain the overall proximate composition and minerals. Galactosides decreased rapidly in all samples. Two days malting promoted a decrease of 91 and 84% in black bean and barley, respectively, while 44% was observed in the soya bean and only 34% in chickpea with a loss of 43% of ciceritol. The highest total levels of inositol phosphates were found in soya bean and black bean (478 and 450 mg%, respectively). IP6 and IP5 were not intensively affected by malting with the higher decrease of 25% observed in black bean. Lectin was detected in significant amounts only in soya bean and black bean and malting promoted 76% loss after 48 h in the black bean samples. The results indicated that short time malting may be useful to improve nutritional characteristics of the samples and that within the legume seeds studied black bean showed better results. ©     

The status and concerns of Chinese malting barley

Chinese spring barley is mainly produced in Inner Mongolia, Guansu, Xinjiang, Heilongjiang, etc. Winter barley areas include Jiangsu, Yunnan, Hubei and some other regions.     

中国啤酒大麦的现状及思考

<正> 一、中国啤酒大麦的基本现状大麦作为一种古老的农作物,在我国的种植业中曾占有重要地位,但随着食物结构和饲料中能量原料作物的改变,我国的大麦面积从上世纪三十年代的1亿亩减至五十年代的5千万亩,又减至八十年代初的3千万亩,近几年约为2200至2300万亩。随着今后啤酒大麦生产的发展和裸大麦深加工的开发,估计大麦     

几种麦芽抗酵母菌粗蛋白含量比较及性质分析

采用硫酸提取及硫酸铵分级沉淀法对八种国内外麦芽的抗酵母蛋白进行了含量分析,得出国产Danpi-2的抗酵母粗蛋白含量最高,达到338μg/g麦芽;同时对抗酵母蛋白的性质进行了分析,得出分子量为10kDa左右的抗酵母粗蛋白能抵抗100℃的高温,把抗酵母粗蛋白加入到发酵液中,酵母数量大量减少,酵母对葡萄糖的利用下降,pH下降缓慢,当粗蛋白含量达到32μg/mL时,酵母生长抑制率达到了50%。     

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.