On the distinction between protein Longzheng
Abstract : This distinction Longzheng protein determination and the determination of the value of production of guiding significance to thoroughly elaborated.
Keywords : Long Ding distinction protein A (B, C) distinguish between high (and low) molecular nitrogen-containing material
Background : Beer Brewing development to the prent, the various brewing process has reached a basic quantitative control, Nitrogen Longzheng distinction is the identification of the extent of protein dissolved in-depth way. However, due to various reasons and not as Brewing manufacturers of conventional analysis project. We are just testing it as a very right to the item or beer wort protein component of reasonable asssment.
1. Long Zheng protein distinction tells
According to the decomposition products of protein peptide chain length and nature, from H. A Lundin made. B. C distinction has become protein Longzheng distinction. A component
is dissolved in beer wort or nitrogen in the polymer material that can be tannin precipitation of proteins and all thermal coagulation protein. A major component is protein with a molecular weight (more than 60,000) as part of a larger, But it dissolved wort to colloidal form. A component wort with heating, cooling precipitates precipitation, some integration into the wort and beer. It beer foam certain benefits, but also have a beer turbidity is the root cau. B component is dissolved or beer wort of molecular nitrogen material (relative molecular mass 12000 -60000's ), that can be ud phosphomolybdic acid precipitation, high molecular nitrogen and tannin precipitation with the nitrogen-containing polymer material difference is mainly peptide, peptone, etc.. B components in wort cooling and fermentation process will lectin precipitation, but a considerable part of the combination with other substances. If combined with carbohydrate glycoproteins, and differences Europium-acid and polyphenols are integrated into complex. The combinations of molecular nitrogen and the beer tastes mellow, the beer bubbles better, But nitrogen molecules can also be combined with polyphenols, turbidity caud beer. C component is dissolved in beer wort or the low molecular nitrogen material, it can not be
phosphomolybdic acid precipitation. mainly of low-peptide and amino acids, including amines, organic nitrogen and inorganic nitrogen. C components need to contain the growth of yeast nitrogen, in yeast metabolism. If insufficient number of amino acids, yeast will have to first synthesis of the corresponding acid. by the turn of ammonia from the role of other amino acids or amines-be, which is also a great deal of acid into diacetyl. High alcohol ester, impact beer tastes; Yeast may also cau adver reproductive effects and the fermentation, Yeast will lead to premature. Yeast was ud after remaining low molecular nitrogen into the beer, as the nutritional content of beer. Another effect of amino acids in the wort boiling process and the formation of carbohydrate melanoidins. It has a special flavor and acidity reduction of pigment material, It beer oxidation and foam is also holding a certain advantage.
2. Analysis Method explained
Principle : nitrogen-containing polymer material in acidic solution easy tannins by precipitation. Phosphomolybdic acid precipitation while high molecular nitrogen-containin
g substances, low molecular weight nitrogen-containing material is not for the above reagent precipitation. Therefore, by testing the beer wort or sulfuric acid, tannin increa nitrogen polymer material precipitation, Determination of the nitrogen content of filtrate from TN minus this value that is a polymer material of nitrogen nitrogen. Another sample using phosphomolybdic acid precipitation, measured the nitrogen content of the filtrate, namely nitrogen substances of low molecular weight volume. Tannin precipitation with nitrogen-containing polymer material filtrate of less nitrogen content of the low molecular weight substances nitrogen volumes for molecular nitrogen substance The volume. Instrument : Nitrogen equipment (automatic or manual Nitrogen measured equipment) hot water boiler (20 ± 1 ° C) reagents : Nitrogen needs of the 16% of the reagent tannic : Tannin weigh 100g distilled water soluble relative density of 1.4 sulfate : 100g concentrated sulfuric acid (98%) by adding distilled water 92g 50% Molybdenum sodium : Molybdenum 50g 100g of sodium into the operation of distilled water : TN Determination : wort or beer from 10 ml tannin precipitation after the filtrate to the determination of nitrogen : wort for 25 ml or 50 ml of beer in Flask, plus 20 ml distilled water and a ml1.4 of
慕课sulfuric acid, mixing, to 20 ° C water bath for 20 minutes after the insulation, plus advance preparation good tannin solution 2.5 ml solution t to scale shaking. Immediately folded filter paper filter ud to clarify the filtrate from 10 ml of nitrogen-fixing. Phosphomolybdic acid precipitation filtrate after the determination of nitrogen : wort for beer or 25 ml in 50 ml Flask, plus 15 ml distilled water and good pre-configured 2.5ml sodium molybdate solution, shaking. At 20 ° C water bath for 20 minutes after the insulation, by adding 1.4 2.5ml sulfate, dissolved scheduled to calibration, shaking. Immediately folded filter paper filter ud to clarify the filtrate from 10 ml of nitrogen-fixing. Calculations : A distinction = A / P × 100% = B distinction B / P × 100% distinction C = C / P × 100% A high reprentative molecular nitrogen; B reprentatives of molecular nitrogen; C. on behalf of low molecular nitrogen; P reprentative of the total soluble nitrogen Results must be expresd as a percentage of tannin attention to the u of nitrogen-containing polymer material precipitation, Temperature changes are very nsitive and the best laboratory temperature can be maintained near 20 ° C. Tannin if not immediately after precipitation filter, it continued to operate ago, at 20 ℃ for 15 minut
椒盐虾怎么做es. Below 20 ° C, can be re-filtrate turbidity, or even the formation of precipitation. The filtrate not remove the filter can be fully blending after the determination of nitrogen. Generally do not operate direct entry into the phosphomolybdic acid, sulfuric acid and sodium molybdate replace. Sodium sulfate and molybdenum production role molybdenum acid, and then samples of phosphate role Generation phosphomolybdic acid. This generation of phosphomolybdic acid precipitation agent than the direct u of phosphomolybdic acid
员工薪酬管理制度3. Application Analysis
Malt solubility of the evaluation of protein caud by the decomposition of material changes, Mr entire system, the most complex and important change, which affects malt quality and flavor of the beer. Foam and non-biological stability of the important material factors. Agreement Act Longzheng wort protein in the scores, on the system can be further clarified Mr process dissolved barley protein, it can also be said that the process of quantification. We pasd a lot of experimental data obtained finishing groping : Area A
"25%, B 15%% 60% C%; If Area A "25% indicated protein dissolved thoroughly enough or dissolved bad. Bad for dissolving the wort in preparation wort should be developed on to keep pace with technology, yeast fermentation to ensure that the necessary nutrition. Wort protein components ultimately the evaluation of the reasonableness of the barley germination stage. not less than 55% of the barley nitrogen material to be formed after the hydrolysis of amino acids, However, in the barley germ was re-synthesis of soluble proteins. Wort amino acid 70% directly from the malt, only 10% -30% of the amino acids from saccharification process itlf. This shows that the protein hydrolysis malt wort component of decisive significance. Malt and the glycosylation process is the ultimate wort protein components of the adjustment to make it more reasonable. Through a lot of analysis, obtained : A zone should be in control of 14 -18%, B contain 17-20% Area C to be 65%. This will ensure the growth of yeast, without causing deterioration of beer colloidal stability. Finished beer colloidal stability and the foam with a large number of instructions through analysis of the results : Area A 10-15% B 14-18% C 70% or so. beer with a good basis for holding the bubble, have a good non-biological stability.
浅谈蛋白质隆丁区分火车票购买时间
摘要：本文对隆丁蛋白质区分的测定方法以及测定值对生产的指导意义作了深入的阐述。
关键词：隆丁蛋白质区分 A（B、C）区分 高（中、低）分子含 氮物质
前言：啤酒酿造发展到现在，酿造的各个工艺过程已基本达到了量化控制，氮的隆丁区分法就是鉴定蛋白质溶解程度的深入方法。但是由于原因种种并没有将其作为酿造厂家的常规分析项目。我们也只是将其作为检测的非常归项目对麦汁或啤酒中蛋白组分的合理性进行评估。
1．隆丁蛋白质区分法细说
按照蛋白质分解产物的肽链长短和性质，由H。Lundin提出了A。B。C区分法，又成为蛋白质的隆丁区分法。
A组分是指溶解在麦汁或啤酒中的高分子含氮物质即能被单宁沉淀的蛋白质及全部热凝固性蛋白质。A组分大都是蛋白质中相对分子质量（60000以上）较大的一部分，但它溶于麦汁中以胶体形式存在。 趣的组词
A组分随着麦汁加热、冷却析出沉淀后，部分溶入麦汁而带入啤酒。它对啤酒的泡沫有一定的益处，但同时又是啤酒产生浑浊的根源。
B组分是指溶于麦汁或啤酒中的中分子含氮物质（相对分子质量12000—60000之间），即能用磷钼酸沉淀的高、中分子氮与用单宁沉淀的高分子含氮物质之差，主要是多肽、胨等。
B组分在麦汁冷却和发酵过程中会凝集析出，但有相当一部分与其它物质结合，如与糖类结合成糖蛋白，与异α-酸、多酚结合成复合物。这些结合物和中分子氮对啤酒的口味醇厚、啤酒泡沫有较好的作用，但中分子含氮物也能与多酚结合，引起啤酒混浊。
C组分是溶解在麦汁或啤酒中的低分子含氮物质，它不能与磷钼酸作用发生沉淀，主要是低肽和氨基酸，也包括胺、有机氮和无机氮。
C组分包含酵母生长需要的氮源，参与酵母新陈代谢。如果氨基酸数量不足，酵母就不得不先合成相应的酮酸，再由转氨作用从其它氨基酸或胺类得到氨基，由此得到的多量酮酸也会转化为双乙酰、高级醇和酯，影响啤酒口味；也可能使酵母繁殖不良而影响发酵的进行，还会引起酵母的早衰。被酵母利用后剩余的低分子氮溶入啤酒，作为啤酒的营养成分。氨基酸的另一个作用是在麦汁煮沸过程中与糖类形成类黑精，它具有特殊香味和还原能力的酸性色素物质，它对啤酒的抗氧化性和泡持性也有一定好处。
2．分析方法阐释
闻天祥
原理：
高分子含氮物质在酸性溶液中易为单宁所沉淀。磷钼酸可同时沉淀高、中分子含氮物质，低分子含氮物质则不为上述试剂所沉淀。因此，将所要测的麦汁或啤酒用硫酸酸化后，加单宁使高分子含氮物质沉淀，测定滤液的含氮量，从总氮减去此值即得高分子含氮物质的氮。另一份试样用磷钼酸沉淀，测得滤液的含氮量，即为低分子含氮物质的量。用单宁沉淀高分子含氮物质的滤液的含氮量减去低分子含氮物质的量即为中分子含氮物质后的量。
仪器：
定氮的仪器（自动定氮仪或手工方法测定的仪器）
恒温水浴锅（20±1℃）
试剂：
定氮需要的试剂
16%的单宁：16g单宁溶于100g蒸馏水
相对密度1.4的硫酸：100g浓硫酸（98%）加入92g蒸馏水
50%钼酸钠：50g钼酸钠溶入100g蒸馏水
操作：
总氮的测定：取麦汁或啤酒10ml
单宁沉淀后的滤液中氮的测定：取25ml麦汁或啤酒于50ml容量瓶，加20ml蒸馏水和1ml1.4的硫酸，混匀，至20℃水浴中保温20分钟后，加预先配制好的单宁溶液2.5ml，定溶至刻度摇匀。立即用折叠滤纸过滤至澄清，取滤液10ml定氮。
磷钼酸沉淀后滤液中氮的测定：取啤酒或麦汁25ml于50ml容量瓶中，加蒸馏水15ml和2.5ml预先配置好的钼酸钠溶液，摇匀。置于20℃水浴中保温20分钟后，加入1.4的硫酸2.5ml老公上司，定溶至刻度，摇匀。立即用折叠滤纸过滤至澄清，取滤液10ml定氮。
计算：
A区分=A/P×100%
B纸制品区分=B/P×100%
C区分=C/P×100%
A代表高分子氮；B代表中分子氮；C代表低分子氮 ；P代表总可溶性氮
结果用百分数表示
必须注意
用单宁沉淀高分子含氮物质时，对温度的变化非常敏感，实验室的温度最好能保持近20℃。若单宁沉淀后不能即时过滤，则在继续操作前，在20℃下保温15分钟。在低于20℃时，滤液能重新混浊，甚至可以形成沉淀。该滤液不必过滤除去，可充分混匀后进行氮的测定。
操作中一般不直接加入磷钼酸，而用硫酸和钼酸钠代替。硫酸和钼酸钠作用生成钼酸，然后和试样中存在的磷酸盐作用生成磷钼酸。这样生成的磷钼酸作沉淀剂比直接用磷钼酸的效果好。
3．应用解析
麦芽溶解度的评价
蛋白质分解所引起的物质变化，是整个制麦过程中最复杂而重要的变化，也是影响麦芽质量和关系到啤酒风味、泡沫和非生物稳定性的重要物质因素。
协定法麦汁隆丁蛋白区分值的测定，就可以进一步明确制麦过程中大麦蛋白质溶解的情况，也可以说是这一过程的量化。我们通过对大量实验数据的摸索整理得出：A区＜25%、B区15%左右、C区60%左右；如果A区＞25%则表明蛋白质溶解不够彻底或溶解不良。对于溶解不良的麦汁我们在制备麦汁时就应制定与之相适应工艺，以保证酵母发酵所
需的营养。
最终麦汁蛋白组分合理性的评价
大麦在发芽阶段，有不少于55%的大麦含氮物质得到水解后形成了氨基酸，但同时在大麦胚芽中又重新合成新的不溶性的蛋白质。麦汁中氨基酸的70%以上直接来自麦芽，只有10%-30%的氨基酸是由糖化过程得来。由此可见，麦芽的蛋白质水解情况对麦汁组分具有决定性的意义，而麦芽的糖化过程是对最终麦汁蛋白组分的调整，使之更加合理。
通过大量的实验分析，得出：A区应控制在14-18%、B区应控制在17-20%，C区应在65%左右。这样既能保证酵母生长需要，又不致使啤酒胶体稳定性变差。
成品啤酒胶体稳定性和泡持性的指示
通过大量分析结果看：A区10-15%、B区14-18%，C区70%左右，这样的啤酒既有良好的泡持基础，又有了良好非生物稳定性。
