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

Abstract

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

Vitamins in brewing: effects of post-fermentation treatments and exposure and maturation on the thiamine and riboflavin vitamer content of beer

“…During the bottle conditioning maturation period, both FMN and riboflavin vitamers levels remained relatively unchanged (Fig. 3B) as the yeast has little requirement for these vitamers under anaerobic conditions and this reflects the results reported previously (19). During this 3 week maturation period, the viability of the yeast culture ( Fig.…”

“…4A), while the TMP and the TDP levels remained relatively unchanged. This utilization of the thiamine is similar to the rapid uptake of the free thiamine vitamers at the start of a beer fermentation reported earlier (19). In typical bottle-conditioning processes, either some residual fermentable sugars are still present at the time of bottling or a small amount of sugar is added to the beer to allow the yeast to ferment just enough to primarily carbonate the beer and to continue to remove unwanted components such as vicinal diketones (59,(77)(78)(79)(80).…”

“…A). Compared with the primary fermentation results reported by Hucker et al , the utilization of free thiamine during bottle conditioning occurs at a slower rate. This is probably due to the decrease in fermentation performance by the yeast, since the majority of the available sugars have already been utilized during primary fermentation.…”

“…In typical bottle-conditioning processes, either some residual fermentable sugars are still present at the time of bottling or a small amount of sugar is added to the beer to allow the yeast to ferment just enough to primarily carbonate the beer and to continue to remove unwanted components such as vicinal diketones (59,(77)(78)(79)(80). This secondary fermentation would act in a similar fashion as reported by Hucker et al, (19), in that thiamine levels would initially decrease (Fig. 4A).…”

“…However, production of wort was found to introduce an even larger number of variables that influence thiamine and riboflavin vitamer content in boiled sweet wort for the production of beer . The fermentation of wort causes no significant changes in any of the riboflavin vitamers or the thiamine mono‐ and di‐phosphate vitamers , while the thiamine vitamer is rapidly utilized by the yeasts and removed from the beer. As discussed by Hucker et al , it is likely that the increased processing attributed to typical lager production and lowered yeast contact times (compared with bottle‐conditioned beers) contribute to the major differences in vitamin content.…”