盐胁迫下萌发大麦热稳定性水溶蛋白的研究

利用Bradford法和SDS-PAGE电泳技术对盐胁迫下大麦发芽过程中热稳定性水溶蛋白进行了测定分析,并检测大麦在盐胁迫下蛋白酶的分泌情况。试验结果表明,高浓度钠盐会抑制其蛋白酶活性,发芽结束时热稳定性水溶蛋白含量增加不明显,在低浓度钙盐胁迫下发芽过程中热稳定性水溶蛋白含量显著增加,但与空白对比其含量有所降低,其蛋白酶活性并没有受到明显抑制,但当钙盐浓度较高时,发芽后期蛋白酶活性受到抑制,发芽结束时其热稳定性水溶蛋白含量增加不显著。由此可证实盐胁迫下大麦发芽过程中蛋白酶能够正常诱导和分泌,但过多的盐分抑制了蛋白质的合成代谢。     

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。     

不同品种大麦种子萌发过程醇溶蛋白变化

以4个品种大麦甘啤2号、甘啤3号、Gairdner和Schooner为材料研究大麦种子萌发过程中蛋白酶活力和醇溶蛋白的变化.国产品种大麦醇溶蛋白含量高于进口品种,但蛋白酶活力发芽24 h以后高于进口品种大麦.在蛋白酶的作用下,国产品种大麦醇溶蛋白降解量大于进口品种大麦,发芽结束时,国产品种大麦醇溶蛋白含量低于进口品种或与之相近.表明与两个进口品种大麦相比,两个国产品种大麦蛋白酶活力升高快,最大酶活力高,醇溶蛋白降解进程快,有制造优质麦芽的潜力.     

同品种不同蛋白质含量大麦主要水解酶活力变化

对不同蛋白质含量的国产大麦甘啤4号大麦发芽过程中α-淀粉酶、β-淀粉酶、蛋白酶、植酸酶、木聚糖酶和过氧化物酶等水解酶活力进行研究.结果表明,两种大麦萌发过程中α-淀粉酶、β-淀粉酶、蛋白酶、木聚糖酶和过氧化物酶的活力的变化规律基本相似,但两种大麦的α-淀粉酶活力均在发芽后122 h时,达到最大值,高氮甘4为57.296u/g(绝干),低氮甘4为57.882u/g(绝干),而两种大麦的植酸酶活力变化规律则有所不同,但同时在发芽后26 h时,两种大麦的植酸酶活力同时达到最大值,高氮甘4为2.569 u/g(绝干),低氮甘4为2.851 u/g(绝干).     

大麦及其发芽过程中热稳定性蛋白的研究

大麦热稳定性蛋白对啤酒的口感风味、泡沫及胶体稳定性等品质起着主要的作用,利用Bradford法和SDS-PAGE电泳技术对大麦及其发芽过程中的热稳定性蛋白组成进行了分析和比较.结果显示,大麦发芽过程中部分热稳定性蛋白条带逐渐消失,热稳定性醇溶蛋白在发芽过程中遭受蛋白水解其含量最终有所减少,热稳定性水溶蛋白在发芽过程结束时其蛋白含量有所增加.从而根据大麦或麦芽中的热稳定蛋白组成及其含量预测啤酒中的蛋白组成,以便改进制麦和酿造技术,获得高质量的麦芽和啤酒.     

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。     

小麦和酿酒大麦发芽过程中主要酶活的比较研究

对小麦、大麦发芽过程主要酶(α-淀粉酶、β-淀粉酶、植酸酶、过氧化物酶和多酚氧化酶)活力的动态变化进行比较研究.结果表明,在发芽过程中,小麦和大麦中几种酶的酶活力变化具有较高的一致性,即发芽前4d酶活不断增加,随后出现下降趋势.     

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.     

国产主要东北大麦和华东大麦热稳定蛋白的比较

大麦热稳定蛋白的含量及组成对啤酒泡沫的形成和稳定均具有重要的作用。利用Bradford法和SDS-PAGE电泳技术对国产东北大麦和华东大麦发芽过程中热稳定蛋白的含量及组成进行了分析和比较,结果显示,两地区间大麦的热稳定蛋白含量及组成存在明显差异,为改良国产大麦的种植及蛋白构成提供借鉴。     

钠离子与大麦发芽相关性的初步研究

从钠离子对大麦发芽过程中主要水解酶系（α-淀粉酶、β-淀粉酶、纤维素酶和蛋白酶）酶活力的影响及在其影响下大麦叶芽长度的动态变化来研究钠离子与大麦发芽的相关性。研究表明：钠离子与大麦发芽的生理过程存在着相关性，如对大麦发芽过程中水解酶系的活力和大麦芽长度的影响，这种相关性随钠离子的添加浓度的改变而呈现出高度的线形相关性。     

Time Course for the Development of Enzymes in Barley1

Barley (Hordeum distichon var. Harrington) was steeped, germinated and extracted to observe the order of enzyme development. Different parts of the barley kernel were extracted to observe the order of enzyme development during the malting process. Five enzymes were investigated: carboxypeptidase (EC 3.4.16.1), endo‐β1–3, 1–4‐glucanase (EC 3.2.1.73), endo‐B1‐4‐xylanase (EC 3.2.1.136), arabinofuranosidase (EC 3.2.1.55), and α‐amylase (EC 3.2.1.1). Early development of carboxypepti‐dase, followed by later development of β‐glucanase, then α‐amy‐lase, confirmed earlier reports concerning the sequence of synthesis for these activities. However, xylanase developed during the steeping of barley and early in germination, whereas other authors found this enzyme to develop much later in the malting process. Enzyme activities developed to higher levels in the proximal end of kernels for all enzymes except xylanase, which was evenly distributed throughout the kernel. Enzyme development was tested in sterile barley annuli [embryo‐less cross sections taken through the grain, and thus comprising rings of tissue with husk outermost and starchy endosperm innermost] under four effector conditions. Water controls mirrored the development pattern observed in whole barley kernels. Gibberellic acid (GA₃) promoted higher total enzyme activity and development of all enzymes at the same time. Abscisic acid (ABA) promoted earlier development of late developing enzymes (xylanase, arabinofuranosidase and α‐amylase) and significantly higher levels of xylanase than when treatment was with water alone. Mixtures of GA and ABA showed a non‐exclusive, combined response of higher activity levels and a shifting of the initiation of enzyme development. Treatment with a combination of GA and calcium chloride triggered signifycantly higher carboxy‐peptidase activity and significantly lower xylanase activity as compared to treatment with GA or with GA/ABA mixtures.     

补光处理对巨峰葡萄冬果生长发育的影响

为探讨补充光源对巨峰葡萄生长发育的影响,对4年生巨峰葡萄进行补光处理,观测处理38d后巨峰葡萄的生长发育情况.结果表明,补光处理能提高葡萄体内多种生长促进型内源激素如生长素、赤霉素和细胞分裂素的含量,降低生长抑制类内源激素脱落酸的含量,对冬季巨峰葡萄的新梢生长有明显的促进作用,增加了光合面积,延缓了叶片的衰老,增大冬季巨峰葡萄果实.     

赤霉酸的添加对成品麦芽中残留量的影响

作为植物生长调节剂,赤霉酸添加到制麦过程中,可以加速大麦发芽,提高麦芽质量。但是若使用不当,会引起麦汁煮沸色度增加、赤霉酸残留量增加等问题。本文选取澳麦、法麦和国产苏北大麦为主要研究对象,考察了制麦过程添加赤霉酸对成品麦芽品质的影响。研究结果显示:赤霉酸对三个不同地区的大麦麦芽质量指标及其赤霉酸残留量的影响趋势基本一致,即添加量在0～0.3mg/kg范围内,对麦芽质量有明显提高,超过0.3mg/kg后趋于平缓。添加赤霉酸对麦汁色度的影响与大麦产地相关,法麦煮沸色度受影响最大,澳大利亚大麦受影响程度最小。成品麦芽中赤霉酸的残留量与制麦时的添加量具有非常明显的正相关性(R~2>0.99))。所以合理使用赤霉酸对麦芽品质的改善和控制具有重要意义。     

二氧化氯气体（ClO2）处理对葡萄内源激素含量的影响

本文以红提葡萄为材料,分析了二氧化氯(ClO2)气体对葡萄贮藏过程中内源激素ABA、IAA、GA3含量的影响,探讨了ClO2对葡萄保鲜的作用机理。结果表明,20mg/L和40mg/L的ClO2处理使葡萄中利于保鲜的IAA、GA3的含量高于对照,促进衰老和脱落的ABA含量低于对照;IAA/ABA大于对照。     

植物生长调节剂对烤烟内源激素、烟碱、多酚含量的影响

植物生长调节剂对烤烟内源激素以及烟碱、多酚含量的影响结果表明,植物生长调节剂GA、IAA、2,4-D不同程度地提高了内源GA、IAA含量,降低了内源ABA含量,其中外源GA、高浓度2,4-D处理效果较为明显;植物生长调节剂ABA较强地提高了内源ABA的含量,而降低了内源GA、IAA的含量,喷施高浓度ABA效果明显,在打顶后30d,内源ABA提高140%,而内源GA、内源IAA分别降低了61.9%、85.0%,内源GA在打顶后20d含量达到高峰,内源IAA、ABA在打顶后30d达到高峰。      

外源植物激素对大麦抗菌蛋白的影响

通过在制麦的浸麦阶段添加赤霉素（GA3）、脱落酸（ABA）、细胞分裂素（6-BA）3种植物激素,考察外源植物激素与大麦抗菌蛋白的关系。结果表明,在发芽结束时,添加GA3的实验组中,0.05 mg/L实验组抗菌蛋白含量最高（为566.6μg/g）,0.5 mg/L实验组蛋白含量最低;在添加ABA的实验组中,20 mg/L的实验组抗菌蛋白含量最高,为514.9μg/g,40 mg/L蛋白含量最低;在添加6-BA的实验组中,20 mg/L的实验组抗菌蛋白含量最高（为484.4μg/g）,10 mg/L的最低。     

断根、环割处理对烟草内源激素水平的影响及激素与钾积累的相关性

本文通过水培试验,对烟株进行断根、环割、断根+环割处理,探究不同部位内源激素含量的水平及其与钾积累的相互关系。试验结果表明,烟草断根、环割后,降低了烟草根系和叶片中IAA、GA3的含量,以及降低了伤流液中的GA3/ABA比值;根系中钾的积累量与叶片、根系中的IAA含量有显著和极显著的正相关关系;伤流液中单位时间内钾的积累量与叶片的GA3含量、伤流液中的GA3/ABA呈极显著和显著负相关;叶片钾的积累量与根系中的GA3含量有显著正相关关系,与伤流液中的GA3/ABA呈显著负相关关系。上述结果说明了断根、环割通过改变烟株根系、伤流液、叶片中不同内源激素的含量和内源激素间的比值,从而调控钾由根系通过伤流液往上运输,最终提高烟叶钾的积累量。其中,断根+环割处理提高烟叶钾积累量的效果最好。      

The (1–3, 1–4)‐β‐Glucanases in Malting Barley: Enzyme Survival and Genetic and Environmental Effects

Eighteen barley genotypes used in Brazilian malting barley breeding programs were characterized in relation to (1–3, 1–4)‐β‐glucanase activity in green and kilned malt. They were tested to determine the loss of enzyme activity during kilning in the malting process and the environmental effects on enzyme activity were measured. The genotypes analyzed showed great variation regarding the enzyme activity in both kinds of malt, in a range from 531.94 to 934.31 U/kg in green malt, and from 187.02 to 518.40 U/kg in dry malt. The mean enzyme activity loss during kilning was close to 60%, very similar to the results obtained in other studies. The loss among genotypes varied from 8.04% to 71.54%. The enzyme activity varied significantly under the different environments tested, showing existence of environmental effects on the genotypes analyzed. Embrapa 127 was the genotype that exhibited the highest enzyme activity in finished malt although it had shown a low activity in green malt, reflecting a negligible loss of activity during kilning. The data indicate promising results to malting barley breeding due to the wide variability exhibited by genotypes as to enzyme activity and levels of isoenzyme with high thermostability.     

Utilization of the Linear Mode of MALDI‐TOF Mass Spectrometry in the Study of Glycation During the Malting Process

The process of glycation during the malting process was monitored by the linear mode of matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐TOF MS). Water‐soluble proteins were investigated and two hulled barley varieties, Jersey and Tolar, were compared to the hulless line KM 1910. The crude extracts of the proteins obtained from the grain, the malt, and aliquots collected every 24 h during the malting process, were mixed with the matrix (2,6‐dihydroxyacetophenone) and analyzed by mass spectrometry. The protein composition of the barley changed during the malting process. The protein patterns did not differ significantly between the three varieties of the barley grains. However, significant differences between the malts were evident. Results showed the influence of the malting process on the glycation of certain water‐soluble barley proteins, nonspecific lipid transfer protein 1 (LTP1) and protein Z, of which the glycated forms survived the brewing process. These major barley proteins are very important for the formation and stability of beer foam and glycation may prevent their precipitation. Analysis results indicated that slight glycation of the proteins had occurred on the second day of malting. The linear mode of MALDI‐TOF mass spectrometry was used as a fast and simple method for monitoring the patterns of low‐molecular weight barley proteins with regard to barley variety discrimination. This procedure also enables the selection of barley varieties suitable for the malting industry.