Vitamins in brewing: the impact of wort production on the thiamine and riboflavin vitamer content of boiled sweet wort

Wort production contains a number of processing steps that are aimed at the optimal extraction of nutrients from malt, including vitamins. This research revealed that the different wort production processing steps imposed different influences on the thiamine and riboflavin vitamer content of the final sweet wort. These vitamins play vital roles within yeast metabolism, where they act as enzyme cofactors. As such thiamine vitamers play a crucial role in many decarboxylating enzymes, while riboflavin vitamers play an integral role in energy production and redox maintenance. While mashing releases valuable starch into the liquor, both thiamine and riboflavin are also extracted. The extraction of these vitamins is the greatest at 65°C and is indirectly linked to the amylase activity. When the starches are broken down during mashing, the thiamine and riboflavin vitamers are gradually released into the mash liquor. The boiling and trub removal (whirlpool) processes impose losses in both vitamins owing to the high temperatures exhibited during these stages. While hop pellets were shown to contribute a small proportion of the vitamers studied, the use of kettle finings caused a significant reduction in both thiamine and riboflavin vitamers. Copyright © 2014 The Institute of Brewing & Distilling     

Vitamins in brewing: presence and influence of thiamine and riboflavin on wort fermentation

Thiamine and riboflavin vitamers are present in a wide range of foods including beer. These vitamers play critical roles in a variety of enzymatic complexes and can promote and maintain metabolism. Currently, the presence and role of these vitamers in the malting and brewing industry have not been widely explored. This research investigated the effects of various fermentation conditions that may lead to the variations in the vitamin content in beer observed by previous researchers. The present research found that during fermentation, the thiamine content of wort is quickly utilized within the first 6 h of a standard fermentation and the uptake of this vitamin is not affected by increases in wort gravity. While no significant changes were observed in extracellular phosphorylated vitamers of thiamine, both free thiamine and thiamine diphosphate accumulated intracellularly during the wort fermentation. Meanwhile extracellular riboflavin vitamers were only poorly utilized during beer fermentations, however flavin mononucleotide rapidly accumulated intracellularly and more so under aerobic conditions. When yeast was exposed to an all‐malt high‐gravity wort, the thiamine or riboflavin utilization was not affected. However, thiamine utilization was reduced in adjunct‐driven high‐gravity worts. Notwithstanding the lowered thiamine uptake under high‐gravity conditions; there were some minor improvements in fermentation performance and yeast viability. The addition of thiamine to an all‐malt wort did appear to enhance yeast viability, both under normal and high‐gravity conditions. Copyright © 2016 The Institute of Brewing & Distilling     

The Role of Malt and Hop Polyphenols in Beer Quality,Flavour and Haze Stability

Pilot‐scale brewing trials of a 12°P pale lager beer were conducted to look at the effect of a modified dose of hop and malt polyphenols on haze, flavour quality, and stability. Results confirmed that malt polyphenols, and particularly hop polyphenols, in the course of wort boiling, improved reducing activity values and the carbonyl content in fresh and stored beers. Hop polyphenols significantly increased reducing activity and decreased the formation of carbonyls (TBA value) in fresh and stored beer. Reduced content of malt polyphenols, combined with the use of hop CO₂ extract, caused an increase in the TBA value in beer. PVPP stabilized beers tended to be lower in reducing activity. Both malt and hop polyphenols affected the intensity of “harsh taste” in fresh beers and a significant influence from PVPP stabilization of beer was not observed. The staling degree of forced‐aged beers depended on the polyphenol content in the brewhouse. Both hop and malt polyphenols had a positive impact on flavour stability. PVPP treatment of beer had a positive effect on the flavour stability of heat‐aged beers. Polyphenols, especially hop polyphenols, slowed down flavour deterioration during the nine month storage period, but the primary effect was seen during the first four months of storage. Storage trials did not show any unambiguous effects for PVPP stabilization on beer flavour stability. Results confirmed the negative impact of malt and hop polyphenols on haze stability, and PVPP stabilization minimized differences in shelf life prediction values between beers prepared with the modified dose of polyphenols.     

Kinetics of free and glycosylated B6 vitamers,thiamin and riboflavin during germination of pea seeds

The effect of germination on the free and glycosylated B₆ vitamers (pyridoxine, pyridoxal, pyridoxamine and glycosylated pyridoxine), thiamin and riboflavin content in pea seed (Pisum sativum L, var Esla) was investigated. In raw peas, the total vitamin B₆ content (sum of all vitamers expressed as pyridoxine) was 2.183 mg kg⁻¹ DM. Pyridoxine was found to be the predominant B₆ vitamer, while only a little amount of glycosylated pyridoxine, the vitamer with the lowest boiavailability, was observed. Thiamin and riboflavin content in raw peas was found to be 7.614 and 2.110 mg kg ⁻¹ DM, respectively. After 6 days of germination, carried out at 20°C, in the dark and with daily rinsing, a significant increase of the total vitamin B₆ content, mainly due to the increase of glycosylated pyridoxine, was observed. The content of pyridoxal and riboflavin increased in peas 7.5 and 2 times, respectively, whereas pyridoxine, pyridoxamine and thiamin decreased by 83, 24 and 25%, respectively, at the end of the experiment. Results obtained for these vitamins during pea germination were fitted to modelling curves in order to predict vitamin content for different germination periods. © 1999 Society of Chemical Industry     

Effect of thermal processing on available lysine,thiamine and riboflavin content in soymilk

Soymilk was heated over a range of temperatures (90–140°C) and times (0–6 h). The available lysine, thiamine and riboflavin content of the soymilk samples were determined. There was no significant change in available lysine during a 3 h heating period at 95°C. At elevated temperatures of 120 and 140°C, optimum heat processed soymilk gave higher measured values of available lysine than did soymilk processed at 95°C. Prolonged heating at 120 and 140°C caused a decline in available lysine. Kinetic data on the thermal degradation of thiamine and riboflavin in soymilk were fitted with first-order kinetics and the kinetic parameters were determined. © 1998 SCI.     

Stability of α-tocotrienol and α-tocopherol in salami-type sausages and curing brine depending on nitrite and pH

We studied the stability of the valuable vitamer nutrients α-tocotrienol and α-tocopherol and options for their protection in salami-type sausages (blended with α-tocotrienol-rich barley oil) and curing brine. Four different sausage formulations were produced containing nitrite curing salt; nitrite curing salt and ascorbic acid (300 mg/kg); nitrite curing salt and carnosic acid (45 mg/kg); or sodium chloride. Initial vitamer contents (100 mg/kg) did not decrease significantly during ripening and decreased only slightly during storage. Ascorbic acid and carnosic acid were found to be effective in preserving the vitamers in fresh sausages. Freeze-drying of sausages resulted in a significant loss of vitamers (97%), particularly after 14-day storage at room temperature, even in the presence of shielding gases. The vitamer content in the curing brine decreased with decreasing pH in the presence of nitrite. A nitrite concentration of 136 mg/L at pH 4 resulted in significant loss (90%) of the vitamers. Sufficient stability of the vitamers in salami-type sausage and curing brine can be achieved by processing, formulation, and storage conditions.     

聚乙烯聚吡咯烷酮吸附多酚物质性质研究及其在无甲醛酿造啤酒工艺中的应用

本文主要研究PVPP(聚乙烯聚吡咯烷酮)吸附多酚的性质,及其在无甲醛酿造工艺中的应用。结果表明,麦汁或啤酒中的敏感蛋白、酒精度、pH以及PVPP的添加量和添加方式等因素对PVPP吸附多酚都有一定影响。当pH在4.0左右,酒精度在3%(V/V)左右时PVPP的吸附效率最高。PVPP在添加量较低的情况下有一定的吸附专一性,主要吸附高分子的聚合多酚,但在添加量较高的情况下,不具备此性质,对单体酚的吸附迅速增加,会降低麦汁或啤酒的抗氧化能力。PVPP结合硅胶使用可以有效替代甲醛在啤酒酿造中的应用,在保证啤酒非生物稳定的条件下,改善啤酒风味稳定性和抗氧化能力。     

啤酒瓶爆炸原因及对策分析

本文对啤酒瓶的强度进行了详细地理论分析，指出造成啤酒瓶爆炸的主要原因是：（1）瓶子的质量较差；（2）瓶子的结构不合理；（3）装运过程中受到碰撞。（4）啤酒瓶回收利用管理不善；（5）啤酒瓶新标准没有得到有效执行。提出了解决啤酒瓶爆炸问题的办法：（1）提高啤酒瓶的强度；（2）在啤酒瓶外表面涂上耐磨防破碎涂料；（3）强制执行啤酒瓶新国标，加强对旧瓶的管理。并呼吁有关部门尽快加强啤酒瓶防爆技术的研究工作。     

使用PVPP提高啤酒稳定性的探讨

PVPP通过酚羟基和羰基之间的氢键结合,进行表面吸附,有效地去除多酚。啤酒经PVPP稳定后达到了胶体的高稳定性,而且口感稳定性更佳。过滤中添加300mg/L,8min、300mg/L,10min、400mg/L,8min的PVPP后,啤酒具有良好的多酚稳定性和较好的蛋白稳定性。     

Vitamin B6 in Raw and Fried Chicken by HPLC

An isocratic anion exchange, high performance liquid chromatography (HPLC) method was developed to analyze for five of the six vitamers of B₆. Recoveries of the B₆ vitamers in a standard were 100% to 97%. Recoveries in fried chicken breast ranged from 96% for pyridoxal phosphate to 102% for pyridoxine (PN). Recoveries in raw chicken breast ranged from 86% for pyridoxamine to 102% for PN. Processing chicken by frying reduced the total vitamer by 6.5%. Vitamers of B₆ were relatively stable to frying.     

Effect of Flour Extraction Rate and Baking on Thiamine and Riboflavin Content and Antioxidant Capacity of Traditional Rye Bread

ABSTRACT:  The effect of rye flour extraction rates and baking on thiamine and riboflavin content, and antioxidant capacity of traditional rye bread were studied and compared with white wheat flour. The content of thiamine was higher (10.9%) in rye dough formulated with dark rye flour (F-100%; extraction rate of 100%) than in rye dough formulated with brown rye flour (F-92%; extraction rate of 92%) that was similar to dough made with wheat flour. The riboflavin content in rye dough made from flour F-100% was also higher (16%) than in dough formulated with flour F-92%, and both provided larger riboflavin content than wheat dough. Baking led to reductions in thiamine of 56% for wheat bread and of 20% for both rye breads; however, this process caused only a 10% decrease in riboflavin for wheat bread and a 30% decrease for rye breads. Trolox equivalent antioxidant capacity, peroxyl radical scavenging capacity, DPPH radical scavenging activity, and Folin–Ciocalteu reducing capacity were higher in rye than in wheat dough and bread. Baking process produced slight changes in antioxidant activity, except for Superoxide Dismutase-like activity where a sharp decrease was observed. Our findings showed that rye breads are an important source of B vitamins and rye breads formulated with dark and brown flours showed better antioxidant properties than wheat bread. Therefore, rye breads should be more widely recommended in human nutrition.     

Effect of oil treatments against the infestation of Callosobruchus chinensis (L.) on the levels of B vitamins in stored legumes

Groundnut, coconut and mustard oil treated whole chick pea, mung bean and pigeon pea were infested with Callosobruchus chinensis (L.) and stored for six months. Samples were analysed at monthly intervals for selected B complex vitamins viz. thiamine, riboflavin and niacin. With increase in storage period, values for all the three vitamins decreased in untreated legues. After two months of storage slight decrease in thiamine, riboflavin and niacin content of coconut oil treated legumes was observed which continued till the end of six months as compared to the other two oil treated counterparts. The storage period was associated with insect infestation, which in turn influenced the B complex vitamins of legumes. Groundnut, mustard and coconut oils were able to protect legumes for six months against insect infestation when applied in small amount (0.5%), whereas coconut oil had protective effect against insect infestation only for four months.     

Analysis of Isinglass Residues in Beer

A method has been developed for the detection of trace quantities of residual isinglass present in fined beers. Isinglass residues in beer are concentrated by means of an antibody raised using isinglass as an antigen. The separated isinglass is hydrolysed to its constituent acids and quantified by measuring the content of hydroxyproline. The limit of quantification of this method, that is the concentration of isinglass in beer which can be distinguished from background levels of hydroxyproline, is 0.17 mg of isinglass/litre of beer (on an isinglass dry weight basis). This method has been used to quantify the concentration of isinglass residues which could be present in brewery and cask conditioned beers, and also to determine whether there is likely to be stratification of isinglass residues in casks.     

PVPP对啤酒中多酚类物质和蛋白质的吸附作用比较

为了比较PVPP对啤酒中多酚类物质和蛋白质的吸附作用,以牛血清蛋白为例,采用PVPP分别处理原啤酒、牛血清蛋白(BSA)溶液以及BSA原啤酒混合溶液。实验发现,在相同条件下,尽管PVPP对牛血清蛋白具有较强的吸附作用,但对啤酒中多酚类物质的吸附作用更强;而在BSA原啤酒混合溶液中,多酚类物质被吸附量远远大于牛血清蛋白。结果表明,多酚类物质通过竞争吸附占据PVPP的吸附活性点。     

The influence of combined storage procedures of foods on B vitamins content demonstrated at the example of heat sterilisation and irradiation

This work presents a literary survey of accessible information on the applications of binary and trinary combinations of preservation methods (thermosterilization and irradiation with other preservation methods) and on their influence on B vitamin groups (thiamine, riboflavin, vitamin B₆ and folacin) in comparison with traditionally used thermosterilization. It refers to the advantages of the combined techniques of preservation as a real possibility to replace the traditional preservation techniques by non-traditional and less destructive processes.     

应用新技术提高啤酒的胶体稳定性

引起啤酒胶体非稳定性混浊的主要物质为蛋白质和多酚物质。可采取在麦汁煮沸阶段加入胶体物质和在贮酒过程中加入硅胶，使啤酒中的高分子蛋白质沉淀而过滤除去。利用PVPP作为多酚吸附剂对啤酒进行二级过滤，可降低啤酒中的多酚物质，也可将PVPP同硅藻土、硅胶联用过滤，降低啤酒的多酚物质。     

A Method of Detection for Residual Isinglass in Filtered and Cask‐Conditioned Beers

Isinglass has been used as a clarification agent in brewing for many years. However, recently its use has come under scrutiny. Due to concerns about food intolerance and food allergies, the EU and other government bodies have introduced legislation obliging food producers to declare those ingredients, additives and process aids, which are listed as allergens, on product labels. One of the affected products that is used in the brewing industry is isinglass. Within the EU, the brewing industry has objected to its inclusion as there is no evidence to suggest it is involved in food allergies. Due to this objection, isinglass has been granted exemption from the regulations for two years, to November 2007. During this time the industry must prove that isinglass is non‐allergenic. This paper presents a simple and sensitive method for detecting the presence of isinglass in beer. The method involves hydrolysing beer samples with acid and measuring levels of hydroxyproline. This amino acid is found in isinglass but not in brewing raw materials. This method will be of use in any investigations involving isinglass. Data are presented showing how the method can be used to test for the presence or absence of isinglass in filtered and cask‐conditioned beers.     

啤酒发酵罐的清洗和灭菌技术

发酵罐的微生物状况对啤酒质量影响很大,清洁无菌是啤酒生产中卫生管理的基本要求。良好的CIP系统可以对发酵罐进行有效的清洗。本文对发酵罐的清洗机理、清洗方法、清洗程序、清洗剂和灭菌剂的选择以及CIP系统的运行质量等问题进行了探讨。     

国产PVPP的性质及对啤酒质量影响的初步研究

对国产一次性及再生型PVPP性质进行了初步研究，与进口产品相比，发现国产PVPP中除一次性PVPP膨胀性较低以外，其它指标相差无几，而再生型PVPP没有明显区别。添加国产一次性PVPP100mg／L-200mg／L时，有利于提高啤酒的非生物稳定性及风味稳定性；在相同的使用次数下，国产再生型PVPP对总多酚的吸附能力略低于进口产品，但损失率略高。     

Alternatives to Isinglass for Beer Clarification

Fish products have been identified as serious allergens and people who are allergic to fish must avoid consuming foods made with fish or fish products. There is no evidence that isinglass (which is made from the swim bladders of certain fish) can cause allergenic reactions in people who are allergic to fish, and the European Food Safety Authority (EFSA) has ruled that it is not very likely to do so. However, many people may still wish to avoid drinking beer which has been clarified with isinglass. Two alternative compounds (which had shown promise in earlier experimental trials) for the clarification of cask ales and brewery conditioned beers were investigated. These were avian collagen and a pea protein extract. Both materials were observed to have a good clarification effect in laboratory scale fining trials and performed well in comparison to isinglass. Brewery trials were conducted using isinglass, avian collagen and pea extract as fining agents and sensory evaluation showed that there were few discernable differences between all three beers. The collagen alternative was ideal in that the data obtained from the laboratory, sensory and analytical trials show that it acted in a similar manner to isinglass and has no significant impact on beer quality. However, it was not thought that brewers would be receptive to using animal products in their beer. The pea extract also worked well and would make an excellent vegetarian alternative to isinglass, however further work is needed to scale up the production of the pea extract in order that it should become an economic option for use in the beer and wine industries.