共查询到19条相似文献,搜索用时 218 毫秒
1.
目的:实验在前期研究的基础上,研究了啤酒泡沫活性蛋白质中Z4蛋白质的单克隆抗体制备(mAb),对单抗特性进行鉴定,用于啤酒生产中泡沫活性蛋白质的鉴定与定量。方法:制备啤酒泡沫活性蛋白Z4蛋白的单克隆抗体,并测定单克隆抗体效价、单抗亚类鉴定及确定单抗识别位点,最后通用Western Blot免疫吸附法确定单克隆抗体的交叉反应性。结果:所得两株Z4蛋白质的单克隆抗体效价可达10^6以上,其均属于IgG1亚类,但具有不同的抗原识别表位,并且对泡沫活性蛋白均具有较好的反应特异性,与浑浊蛋白、LTP1和Z7无交叉反应。为快速鉴定啤酒泡沫蛋白质中Z4蛋白质研究提供了基础。 相似文献
2.
泡沫蛋白质是啤酒泡沫的骨架,其含量和性质很大程度上决定了啤酒泡沫的质量.蛋白质Z和脂转移蛋白(LTP)是啤酒泡沫蛋白质中的关键组分,实验究考察了啤酒酿造过程中泡沫蛋白质的变化过程.结果显示:在糖化过程中,分子量为53ku及20~40ku的蛋白质被分解,蛋白质Z及LTP的含量没有太大变化;麦汁煮沸过程中蛋白质含量逐渐减少,蛋白质Z、LTP1和LTP2分别减少了11%、32%及26%;主酵过程中,蛋白质Z、LTP1和LTP2的降幅较大,分别为12%、59%和31%;后酵过程中,蛋白质Z和LTP1的含量基本不变,LTP2的含量逐渐降低,到后酵结束,LTP2的降低幅度达22%. 相似文献
3.
4.
5.
6.
泡沫蛋白质对啤酒泡沫性能有重要影响。采用圆二色光谱技术研究啤酒泡沫蛋白质和麦芽蛋白质的二级结构构象特点,通过SDS-聚丙烯酰胺凝胶电泳(1D SDS-PAGE)与液质(LC-MS/MS)联用对啤酒泡沫蛋白质进行分离与鉴定。结果显示,麦芽蛋白质以α-螺旋结构为主,而啤酒泡沫蛋白质以β-折叠和无规则卷曲为主,并未表现出典型的α-螺旋双负峰特征,这种结构有利于泡沫蛋白质的疏水性,从而有利于啤酒泡沫的稳定性。经质谱检测,啤酒泡沫蛋白质中共鉴定出11种蛋白质,包括蛋白质Z4、LTP1、BDAI-1及部分酶抑制剂和少量醇溶蛋白片段。 相似文献
7.
8.
9.
在中型(50L)和小型(700—800mL)酿酒试验中,利用免疫化学技术包括酶联免疫吸附法(ELISA),对通过麦芽性状来预测啤酒质量的方法进行了研究报道。该方法主要在啤酒泡沫蛋白和利用硅胶提取的蛋白质中加入多克隆抗体和单克隆抗体,通过抗原抗体间的反应和免疫印迹进行鉴别,研究发现ELISA法可以鉴定不同的麦芽蛋白质。随着免疫化学技术的发展,该方法可为酿造者选择高质量的麦芽,以提高啤酒泡沫的稳定性和降低浑浊形成的机率提供依据。 相似文献
10.
蛋白质分解酶 A,是发酵过程中酵母细胞分泌的产物,已证实能降解泡沫活性蛋白从而降低啤酒泡持性。为了提高测定蛋白质分解酶 A 的精确度,研究者合成了一种新的荧光物质MOCAc-Ala-pro-Ala-Lys-Phe-Phe-Arg-Leu-Lvs(Dnp)-NH_2。该物质能快速有效的检测出发酵麦汁和商品啤酒中蛋白质分解酶 A 的含量。该酶检测蛋白质分解酶 A 的灵敏度比其它几种报道过的酶蛋白、合成蛋白高几百倍。这种新的测定方法促进了酵母活性测定和酵母处理相关产业的发展,并为解决纯生啤酒的泡沫问题提供检测手段上的帮助。 相似文献
11.
The effect of barley germination and kilning on three putative beer foam-positive proteins was investigated by immunoblotting and ELISA procedures. These procedures involved the use of specific antibodies raised to purified lipid transfer protein 1 (LTP1)and the two protein Z forms, Z4 (BSZ4) and Z7 (BSZ7). The free fraction of BSZ4 and BSZ7, and all LTP1 were extracted by aqueous salt-solution from barley and malt. The addition of reducing agent allowed the extraction of bound BSZ4 and BSZ7. A previously undescribed fraction of BSZ4 and BSZ7, refered to as latent, was extracted with SDS and reducing agent. The barley combined fraction (free + bound fractions) was surveyed in 93 barley varieties to show that BSZ4 was the dominant isoform, on average constituting ?80 % of all protein Z. Considerable variation was observed between varieties in the level of LTP1 (502–1144 μg/g) and the combined fractions of BSZ4 (18–2136 μg/g) and BSZ7 (38–771 μg/g). The free fraction is expected to be more available for extraction into wort during mashing than the bound or latent fractions. The level of LTP1 did not change substantially during germination, but a significant proportion of the latent and/or bound protein Z fractions was converted into the free fraction. In the seven varieties studied the free fraction of BSZ4 and BSZ7 increased 149–300% and 49–141%, respectively. Proteolytic cleavage in the reactive site loop converts protein Z to heat- and protease-stable forms that survive the brewing process. During germination most of the free BSZ4 and 30–70% BSZ7 was converted to the cleaved form. Kilning was found to reduce the amount of protein Z and LTP1 that could be extracted by 10–30% and 7–37%, respectively, which is likely to be counter productive for foam quality. These results suggest that barley variety selection and optimisation of germination and kilning protocols during malting may be opportunities for improvement of beer foam quality. 相似文献
12.
Protein Z4, the most abundant form of serpin protein Z of Hordeum vulgare, is one of the major constituents of beer foam and inhibits the activity of serine proteases. The possible influence of protein Z4 on malt proteases, which impact malt quality, is of interest for brewers. In addition, the persistence of Z4 in the brewing process and the ensuing presence of Z4 in beer matters to brewers because of its impact on foam. In order to analyse the influence of Z4 on protease inhibition and beer gushing, Pichia pastoris cells were heterologously transformed with the Z4 coding gene and the protein was recovered from the supernatant of a transformant's liquid culture. Agar diffusion assays showed that the recombinant Z4 protein had an inhibitory effect on proteases present in barley malt. Heat denaturation of the protein impaired protease inhibition and revealed degradation of the structure of Z4. The effect of Z4 on hydrophobin‐induced gushing was analysed by addition of the protein to beers pre‐treated with the class 2 hydrophobin FcHyd5p. Results demonstrated that addition of protein Z4 to gushing beer reduces the overflow volume considerably. Heat treatment again had a negative impact on the gushing reduction capacity of Z4. Copyright © 2014 The Institute of Brewing & Distilling 相似文献
13.
大豆蛋白纤维与有色涤纶混纺工艺研究 总被引:1,自引:1,他引:1
介绍了大豆蛋白纤维的特点,结合生产色纺纱的实践,通过工艺试验,分析了纺纱工序影响色纺纱质量的一些因素,为提高大豆蛋白纤维与有色涤纶混纺纱的质量提供参考依据。 相似文献
14.
15.
16.
17.
18.
19.
锁阳螺旋藻营养片生产工艺及其蛋白质营养价值的评价 总被引:1,自引:0,他引:1
以锁阳提取物和螺旋藻粉为主要原料,经方差分析,筛选出最佳配比,采用直接成型制片工艺,生产锁阳螺旋藻营养片片。应用模糊识别法和氨基酸比值系数法,分别以鸡蛋蛋白质为标准蛋白,以WHO/FAO氨基酸参考模式为评价标准,对锁阳螺旋藻营养片蛋白质营养价值进行了全面评价。结果表明:锁阳螺旋藻营养片中含有18种氨基酸,总含量为42.75%,蛋白质中氨基酸种类齐全,必需氨基酸(EAA)占总氨基酸量的36.5%,色氨酸为第一限制氨基酸,含硫氨基酸为第二限制氨基酸,氨基酸比值系数为0.54和0.72。 相似文献