不同品种大麦发芽工艺的调整

文章介绍了江苏、加拿大、澳大利亚、新疆等地的大麦品种的特点，与产地的关系，工艺上应采取的处理措施，及麦芽干燥工艺。最后分别对这4个品种提出了结论意见。（陆月霜）     

大麦发芽过程中内源激素的变化

选用进口大麦Gairdner和国产大麦甘啤二号为原料,分析比较了发芽过程中赤霉素、生长素和脱落酸等内源激素含量的变化规律。研究结果表明,3种激素在两种大麦发芽过程中均呈现出随发芽时间上下波动的趋势,且两种大麦在发芽过程中各激素含量的变化规律基本一致。同时,赤霉素均有刺激并诱导其他两种内源激素的作用。     

低剂量X射线系统动力学机理分析及对大麦发芽的影响

建立了X射线强度与大麦种子发芽关系的系统动力学模型,阐释并确证了X射线对发芽大麦的影响和变化机理。研究发现,X射线对大麦种子发芽阶段的芽长、根长、生物量产生抑制作用,接受剂量为1 059.65 μSv/s,试验组Ⅰ在3 d后淀粉、蛋白质和脂肪含量分别比对照组延迟增加了19.8%,31.6%,33.3%,可溶性膳食纤维降低了41.8%,且变化程度与X射线强度呈正相关,但X射线对发芽率没有显著影响。     

低剂量X射线系统动力学机理分析及对大麦发芽的影响

建立了X射线强度与大麦种子发芽关系的系统动力学模型,阐释并确证了X射线对发芽大麦的影响和变化机理。研究发现,X射线对大麦种子发芽阶段的芽长、根长、生物量产生抑制作用,接受剂量为1059.65μSv/s,试验组Ⅰ在3 d后淀粉、蛋白质和脂肪含量分别比对照组延迟增加了19.8%,31.6%,33.3%,可溶性膳食纤维降低了41.8%,且变化程度与X射线强度呈正相关,但X射线对发芽率没有显著影响。     

大麦发芽过程中内源激素对大麦蛋白组分及蛋白酶活力影响

选用进口大麦Gairdner和国产大麦甘啤二号,分析比较了两种大麦发芽过程中赤霉素、生长素和脱落酸等内源激素含量的变化。结果表明,3种激素在两种大麦发芽过程中均呈现出随发芽时间上下波动的趋势,且两种大麦在发芽过程中各激素含量的变化规律基本一致,同时探讨促进生长激素和抑制生长激素的比例对大麦发芽过程中蛋白酶活力的影响。实验结果表明,随着促进生长激素和抑制生长激素比例的升高,两种大麦发芽时蛋白酶活力均有较大幅度的增长,加速了大麦发芽过程中醇溶蛋白含量的降低及热稳定蛋白的释放。     

一种预测浸麦工艺对水敏感性大麦发芽影响的数学模型

一种新开发的方法用于模拟大麦在浸麦及浸麦后的发芽情况，这一方法是基于实验室中采用不同浸麦程序，不同的湿浸和断水时间，不同温度、水敏感性以及不同的发芽方法，这一模型可以用于分析浸麦及发芽，以设计浸麦工艺来生产均一性的麦芽。     

原子发射光谱法测定大麦发芽时金属离子的代谢

大麦在发芽过程中大麦内部的金属离子大麦有结合态与游离态2种存在状态。利用原子发射光谱法跟踪监测其金属离子总含量和游离态含量的变化,结果显示：在大麦发芽过程中总的离子含量一般呈现出单调的变化,而游离态的离子含量随发芽时间的不同呈现出波动变化。金属离子不同的存在状态有着不同的生理功能,通过跟踪监测离子的2种状态的含量变化,可以为研究金属离子在大麦发芽过程中的生理作用提供新的方法。     

大麦发芽过程中蛋白质组的变化研究

通过双向电泳技术监测大麦发芽过程中水溶蛋白质组的变化,明确大麦发芽过程中蛋白质组的变化规律,为麦芽制造提供一定理论依据。以澳麦     

大麦发芽过程中多糖水解酶系的作用

细胞壁降解对发芽大麦中胚乳的代谢起着重要的作用。阿拉伯木聚糖和(1→3，1→4)—β—葡聚糖两者总和超过细胞壁重量的90％。他们的降解需要多糖水解酶和寡糖酶的共同作用。(1→3，1→4)—β—葡聚糖内切酶在降解β—葡聚糖过程中释放出寡糖，寡糖再由β—葡聚糖外切酶和β—葡萄糖苷酶转化为葡萄糖。近来，后两种酶从发芽大麦中得以分离纯化，此足以证明发芽大麦中的(1→3，1→4)—β—葡聚糖外切酶来源于广泛存在于植物细胞中并能水解细胞壁多糖的(1→3)—β—葡聚糖酶。阿拉伯木聚糖的水解液需要一系列的酶，但对此研究较少。(1→4)—β—木聚糖内切酶已被纯化并分离出相应的cDNAs和基因。虽然(1→4)—β—木聚糖内切酶和α—L—阿拉伯呋喃糖苷酶被多次报道，但对它们性质的研究还不深入。     

EFFECT OF IRRADIATION ON THE MALTING QUALITY OF BARLEY

Two six-row barley cultivars, DL 70 and C 164 were subjected to Co⁶⁰ gamma irradiation in the range of 0 to 250 Krad and malted with and without gibberellic acid treatment. Barley irradiated with doses up to 75 Krad produced normal malts when compared to the controls. Irradiation doses of 125 and 250 Krad significantly increased the malt yields but considerably decreased the α-amylase activity. Gibberellic acid significantly increased the enzyme activity and degree of modification of the irradiated and the control malts.     

青稞萌发中两种淀粉酶的研究

分析研究了不同浸泡条件对青稞吸水率的影响；测定了不同发芽条件下青稞萌发过程中α-淀粉酶及β-淀粉酶活力的变化。确定了青稞萌发过程α-淀粉酶和β-淀粉酶的最大酶活力形成条件为萌发温度16℃，吸水度46％，萌发时间5d。     

IMMUNOCHEMICAL. STUDY ON BARLEY α-AMYLASES*

Polymorphism of barley α-amylase was studied using immuno-electrophoresis and immuno-absorption in a gel medium with an anti-barley malt α-amylase immune serum: α-amylase from germinated seeds is antigenically heterogeneous. The two antigens which were demonstrated evolved differently upon germination. The bulk of the enzyme activity extracted from the seeds at different stages of germination differed antigenically from α-amylases found in developing barley seeds.     

萌发大麦种子蛋白组分含量变化研究

采用蛋白质组分连续累进提取分析法，检测了垦啤8号、甘啤4号、Harrington、Es．terel四个品种大麦种子萌发前后各蛋白组分的含量变化。结果表明：大麦种子中清蛋白含量较低，占总蛋白含量的3％～5％，种子萌发后，清蛋白含量迅速升高，发芽第四天达到最大值，含量占10％左右，绿麦芽焙焦后，含量略有下降；球蛋白含量变化较为复杂，在种子发芽2天后达到最大值，由3％升至6％左右；醇溶蛋白在种子萌发过程中明显减少，Esterel品种变化最大，减少了总蛋白质的7．14％，其它三个品种减少了4到6个百分点；谷蛋白含量在萌发过程中略呈升高趋势，但变化不大。     

脉冲电场对啤酒大麦萌发性质的影响

在啤酒麦芽制备过程中引入脉冲电场(PEF)技术,对浸渍后的大麦种子进行不同电场强度的处理,以了解PEF对大麦萌发性质的影响。结果表明,PEF处理有利于提高大麦萌发活力和相关理化性质。大麦籽粒经电场强度1.5、3.0、4.5、6.0、7.5 kV/cm处理后,萌发大麦的芽长、根长、根数、鲜重、干重、发芽势、发芽率、简化活力指数、还原糖含量、β-葡聚糖酶活力、α-淀粉酶活力、β-淀粉酶活力、可溶性蛋白质和氨基态氮含量等指标与对照组比较均有明显提高,发芽势、根长、β-葡聚糖酶活力、α-淀粉酶活力和β-淀粉酶活力提高的幅度分别为38.96%、43.33%、21.46%、26.48%和23.57%。对14项指标进行主成分分析的结果表明,当电场强度为6.0 kV/cm时,脉冲电场对大麦萌发的促进效果最好。     

Quantifying cyanogenic glycoside production in the acrospires of germinating barley grains

Ethyl carbamate is an undesirable trace component in distilled beverages and its content in Scotch whisky is largely determined by the cyanogenic pre‐cursor, epi‐heterodendrin (EPH) from malted barley. A rapid colorimetric procedure can identify cultivars that do not produce EPH and attempts were made to quantify this test, to determine differing levels of production. Using a given fresh weight of acrospire tissue from germinated grain, it was possible to distinguish between genotypes but differences between replicates were substantial. Acrospire length was not a reliable indicator of EPH production and genotypes differed not only in the quantity of EPH produced but in the rate and pattern of production. © 1999 Society of Chemical Industry     

CELLULASES OF PLANT AND MICROBIAL ORIGIN IN GERMINATING BARLEY

Cellulase activity in crude extracts of germinating barley is at least five-fold higher in hulled than in hull-less cultivars. Surface sterilization of the grain prior to germination reduces cellulase to levels that are similar in all cultivars. In hulled barley most of the cellulase detected during germination is probably of microbial origin, but there is circumstantial evidence to suggest that significant activity can also be attributed to cellulases of plant origin. The micro-organisms associated with germinating grain reside largely in the hull and the major fungal species present on the hulled variety Clipper were Aureobasidium pullulans, Rhizopus stolonifer and Penicillium spp. Surface sterilization of the grain with silver nitrate, followed by steeping in a solution containing antibiotics, completely eliminated microbial growth on hull-less cultivars. After similar treatment of a hulled barley two yeasts could be detected. The results emphasize the importance of eliminating microbial growth prior to studies of polysaccharide hydrolases which develop during the germination of barley and which are assumed to be of plant origin.     

ISOELECTRICFOCUSING AND IMMUNOCHEMICAL ANALYSIS OF GERMINATED BARLEY α-AMYLASES AFTER FREEZE-DRYING AND KILNING

Isoelectricfocusing analysis showed that germinated barley contained three groups of α-amylase—α-amylase I a minor component and major components α-amylases II and III. During kilning there was a significant conversion of α-amylase III to α-amylase II. These two enzymes were shown to have immunochemical identity.     

高蛋白含量大麦发芽过程中蛋白质组分及其含量变化分析

本文利用SDS-PAGE电泳技术,比较分析了蛋白质含量较高的国产甘啤4号大麦和蛋白含量适中的进口质量大麦Gairdner在发芽过程中蛋白质组分及其含量变化.研究发现,高氮甘4在发芽过程中,水溶性蛋白的低分子质量蛋白分解较强烈;盐溶蛋白的中分子质量蛋白分解较多;醇溶蛋白的高、中分子质量蛋白亚基组分含量较高,而其分解效果较差;碱溶蛋白中高分子质量蛋白大量的分解为中分子质量蛋白亚基.本文基本找到了高蛋白含量大麦发芽过程中不同蛋白组分及其含量变化的规律.