糖化过程稳定剂卡拉胶的应用研究

文章通过研究不同用量的卡拉胶对麦汁中蛋白质絮凝效果及麦汁浊度的影响,建立了浓度梯度试验方法,指导麦汁煮沸过程中卡拉胶的添加。通过酿造对比试验,减少卡拉胶添加50%,麦汁指标、发酵过程、成品指标、保质期、品评方面均满足标准要求。     

卡拉胶在啤酒酿造过程的应用

主要论述麦汁澄清剂一卡拉胶能够加快麦汁中蛋白质沉淀,特别是除去冷浊蛋白质十分有效,大大改善麦汁的浊度,从而提高啤酒的非生物稳定性。具体从理论到实际应用方面阐述卡拉胶的特点、使用方法、注意事项以及实验小试比较和我公司在大生产的应用情况。     

卡拉胶在啤酒酿造过程的应用初探

论述了麦汁澄清剂－卡拉胶能够加快麦汁中蛋白质沉淀，特别是十分有效地除去冷浊蛋白质，从而大大改善麦汁的浊度，提高啤酒的非生物稳定性。从理论到实际应用方面阐述卡拉胶的特点、使用方法、注意事项以及实验小试比较和在大生产的应用情况。     

卡拉胶在啤酒酿造中的应用

主要论述麦汁澄清剂———卡拉胶能够加快麦汁中蛋白质沉淀,特别是除去冷浊蛋白质十分有效,大大改善麦汁的浊度,从而提高啤酒的非生物稳定性。     

使用麦汁澄清剂卡拉胶改善啤酒非生物稳定性的探讨

论述了麦汁澄清剂卡拉胶,能够有效地同啤酒中引起非生物浑浊的蛋白质、类脂、葡聚糖等结合,形成沉淀析出,从而使麦汁澄清透明,有利于提高啤酒的非生物稳定性。对卡拉胶的特性,澄清麦汁的原理以及生产应用情况,使用效果进行了具体的阐述。     

麦汁澄清剂(卡拉胶)对啤酒酿造的影响

麦汁澄清剂(卡拉胶)是海洋藻类中提取的大分子 D-半乳聚糖,在麦汁煮沸时带负电荷,而麦汁中的蛋白质颗粒带正电荷,它们相遇电荷相互中和,形成电中性密实的凝聚物,达到去除麦汁中高分子蛋白质的目的,以提高啤酒非生物稳定性。我们通过一年多对卡拉胶在啤酒生产中的应用性试验,初步得出了一些有关数据,现总结如下:     

卡拉胶在啤酒酿造中的应用

麦汁澄清剂－卡拉胶能够加快麦汁中蛋白质沉淀,特别是除去冷浊蛋质十分有效,大大改善麦汁的浊度,从而提高啤酒的非生物稳定性。     

卡拉胶在啤酒生产中的应用

引起啤酒非生物混浊的成分包括：蛋白质、多酚物质、无机盐、碳水化合物以及某些金属离子等。卡拉胶是啤酒酿造过程中比较理想的澄清剂。在麦汁煮沸结束前10min添加卡拉胶．能改善麦汁外观质量；加快麦汁过滤速度；吨酒耗硅藻土量可节省20％左右；水耗、电耗下降5％左右。酿制出的啤酒各项理化指标均符合国家或企业标准。     

麦汁煮沸与蛋白质凝聚

[概述]麦汁煮沸是基本决定麦汁组成、浓度和色泽等的生产操作,最主要的变化是蛋白质的凝聚和分离。煮沸过程中的蛋白质凝聚有两种形式:一种是在加热以及 PH 条件影响下的蛋白质变性凝固,这种形式去除的多为溶于麦汁的可凝固性氮,另一种是蛋白质与其它成分,如单宁、卡拉胶、部分酒花树脂以及金属离子的络合与复合物。麦汁煮沸去除多余的蛋白质,对酒体的组成、口味及提高啤酒的非生物稳定性有其重要意义。     

关于几种麦汁澄清剂的对比试验

麦汁澄清度是生产优质啤酒的基础.通过对卡拉胶、复合硅胶和单宁对啤酒麦汁澄清对比试验.在煮沸结束前10分钟加入,蒸发强度控制在9%,3.0×10-4(300ppm)颗粒卡拉胶能加快冷浊蛋白质沉淀,使麦汁清澈透明;1.5×10-4(150ppm)的复合硅胶能有效吸附单宁、多酚、蛋白质,可明显去除热凝固物;单宁酸对除去热凝固性氮物效果明显,但与蛋白质结合后易使麦汁混浊.(永光)     

小麦谷朊蛋白对霞多丽葡萄汁澄清效果的研究

本实验以小麦谷朊蛋白为澄清剂,添加浓度分别为250、375、500、625mg/L,对霞多丽葡萄汁进行澄清效果研究。结果表明:小麦谷朊蛋白添加量为500mg/L时,沉淀物最多,葡萄汁澄清透亮。与对照相比,小麦谷朊蛋白处理的葡萄汁,其色价、总酸及总酚含量均降低,但蛋白质含量有所升高。通过与皂土、单宁-明胶澄清效果比较,认为小麦谷朊蛋白可以作为葡萄汁的澄清剂。     

苦荞麦麸复合饮料的研究

为综合开发苦荞功能食品,以苦荞麦麸为主要原料,对苦荞麦麸复合饮料的工艺进行研究。结果表明:过40目筛的苦荞麦麸粉用质量比1︰30的水于90℃浸提10 min,分别取体积分数80%的麦麸浸提液、15%的梨汁、5%西柚汁,并加入1%质量分数的蜂蜜,经海藻酸钠进行澄清过滤,所得苦荞麦麸复合饮料,其总黄酮含量为0.256 mg/mL,呈淡褐色、具有苦荞特有的清香。     

麦汁煮沸与啤酒稳定性

本文论述了麦汁煮沸对啤酒非生物稳定性、啤酒生物稳定性、啤酒风味稳定性和泡沫稳定性的影响。     

Fibres as carriers for Lactobacillus rhamnosus during freeze-drying and storage in apple juice and chocolate-coated breakfast cereals

The capability of different fibre preparations to protect the viability and stability of Lactobacillus rhamnosus during freeze-drying, storage in freeze-dried form and after formulation into apple juice and chocolate-coated breakfast cereals was studied. In freeze-drying trials wheat dextrin and polydextrose proved to be promising carriers for the L. rhamnosus strains: both freeze-drying survival and storage stability at 37 degrees C were comparable to the control carrier (sucrose). Using apple fibre and inulin carriers resulted in powders with fairly good initial freeze-drying survival but with poor storage stability at 37 degrees C. When fresh L. rhamnosus cells were added into apple juice (pH 3.5) together with oat flour with 20% beta-glucan the survival of the cells was much better at 4 degrees C and at 20 degrees C than with sucrose, wheat dextrin and polydextrose, whereas with freeze-dried cells no protective effect of oat flour could be seen. The stability of freeze-dried L. rhamnosus cells at 20 degrees C was higher in chocolate-coated breakfast cereals compared to low pH apple juice. Similar to freeze-drying stability, wheat dextrin and polydextrose proved to be better carriers than oat flour in chocolate-coated breakfast cereals. Regardless of their differing capability to adhere to fibre preparations the two L. rhamnosus strains studied gave parallel results in the stability studies with different carriers.     

大豆蛋白果汁的研制

研究了高蛋白果汁的制备方法。在果汁等酸性饮料中添加大豆蛋白,会导致产品中蛋白质的沉淀。利用葡萄糖酸内酯(GDL)诱导大豆蛋白形成凝胶,将蛋白加入到果汁中,研究了不同GDL诱导量和不同蛋白浓度对产品稳定性的影响,并阐明了此方法可以稳定果汁中蛋白的机理。研究表明,降低蛋白的荷电量和粒度是在果汁中稳定蛋白的主要原因,并且适度的GDL和蛋白的浓度,以及均质压力和次数,都会对产品的稳定性起到明显的改善作用。     

植物乳杆菌YSQ 规模化生产的低成本培养基配方优化

通过单因素试验、Plackett-Burman试验设计及响应面法筛选适于植物乳杆菌YSQ株大规模发酵的低成本培养基。结果表明：单因素试验确定培养基成分：碳源为玉米粉、次粉+蔗糖;氮源为豆粕;番茄汁作为生长因子供体。利用Plackett-Burman试验设计筛选出影响植物乳杆菌生长的4个主要因子：次粉、豆粕、K2HPO4和MnSO4。最陡爬坡、中心优化组合及响应面分析确定培养基各组分的最适添加量为：玉米粉10g/L、豆粕15.5g/L、次粉1.2g/L、蔗糖5g/L、番茄汁150mL/L、K2HPO4 1.1g/L、MnSO4 0.28g/L、MgSO4 0.3g/L。优化后,植物乳杆菌发酵18h的菌落总数从优化前的8.73×108CFU/mL(玉米粉、豆粕、次粉的混合料)提高到2.68×1010CFU/mL。     

枸杞菊花保健玉米面包的研制

以小麦粉和玉米粉为主要原料,加入枸杞和菊花制得的浸提液以及蜂蜜等辅料,研制成枸杞菊花保健玉米面包。并通过实验确定其最佳配方和最优工艺条件。     

Retention of nitrogen from ground barley grain supplemented with lucerne or barley leaf juice in long-term balance experiments conducted with rats

The biological value (BV) and true digestibility of lucerne and barley juice protein mixed with ground barley grain were estimated using the Thomas-Mitchell balance method with rats. The BV with forage barley juice protein was similar to that of barley grain protein alone and was not improved by any of the applied treatments. The BV with lucerne juice protein was lower and was improved by separating the ‘brown juice’ after heat coagulation. Better results were obtained in a group fed diets with lowered levels of potassium and calcium which suggested an imbalance in the mineral content of lucerne juice; there was no difference in water consumption. The haemoglobin content of the blood of rats fed lucerne or barley juice alone was lower than that of animals fed plant juice/barley grain mixtures. No pathological lesions were observed in the guts, kidneys and livers of the rats.     

Effect of feeding different diets on the exocrine pancreatic secretion of nitrogen,amino acids and enzymes in growing pigs

Five barrows were fitted with permanent pancreatic re-entrant cannulas to determine the influence of diet on exocrine pancreatic secretions in the weight range from 40 to 65 kg. The pigs were fed four diets. Diets 1 and 2 were based on corn starch and contained 18.6 and 16.9 % crude protein (dry matter basis) from soybean meal and canola meal, respectively. Diets 3 and 4 contained 93.9 % wheat and barley, respectively. In the same order, the crude protein contents (dry matter basis) of these diets were 14.4 and 11.2%, respectively. The experiment was carried out according to 4 × 4 Latin square design. Each experimental period comprised 12 days. Following an adaptation period of 8 days, pancreatic juice was collected from 08:00 on day 9 to 08:00 h on day 10 and from 08:00 on day 11 to 08:00 h on day 12. The pigs were fed twice daily, at 08:00 and 20:00 h, 800 g each meal. Despite large differences, up to 23%, between the overall mean values of the parameters that were measured there was no effect (P > 0.05) of diet on the volume of secretion of pancreatic juice, the pH and the secretion of total and TCA-precipitable nitrogen. Due to the high level of within-study variation there was also no effect (P > 0.05) of diet on the secretion of amino acids and the total activity of trypsin, chymotrypsin, α-amylase and lipase in pancreatic juice.