Factors related with dissolved silicon content in Belgian beers

The role of silicon (Si) in human metabolism is not well studied, but more and more agreement exists that it is an essential element for bone mineral density, potentially reducing the chance to develop osteoporosis and bone fractures. Si also reduces the biological availability of aluminium.Beer is one of the prime sources of Si for humans and is a quintessential part of Belgian heritage. Sripanyakorn et al. (2004) found that Si concentrations in blood serum rise to a peak within 2 h after ingestion of beer, suggesting an efficient uptake of dissolved Si into the bloodstream. A substantial fraction of the beer Si is effectively retained within the body. Although other food products have higher concentrations of Si per weight unit (e.g. cereals and soups), beer has the highest in vitro availability of Si found in a wide range of consumption products (Robberecht et al., 2009). Si in the beer originates from the husks of the barley malt. During the brewing process most of the deposited amorphous Si remains in the husks, but significant Si is extracted into the wort during mashing and much of this endures into the beer. Belgium represents an excellent case study to investigate variation of Si concentrations among a wide range of beer styles, fermentation processes and ingredients. Several studies have confirmed considerable variability in Si concentrations in beer. Sripanyakorn et al. (2004) found no direct link to beer type, country of origin or alcohol content. Other studies have suggested a link to fermentation (e.g. Robberecht et al., 2009). In our study 120 Belgian beers were analysed for dissolved Si and the results compared with typical beer parameters (alcohol content, real extract, original extract, fermentation degree, colour, pH, bitterness). Process conditions were also taking into account.The study confirmed that all beers contain significant dissolved Si, while some beers contain extraordinary high concentrations. Most Si is available in strong ales like abbey and trappist ales. Concentrations of Si ranged between 214 and 2,071 μmol L − 1.The alcohol content was related to the Si content. A more significant relation is found between the real extract and the Si content. The real extract, diminished with the eventual sugar added to sweeten the beer, is a possible measure for the amount of grain raw materials used in the production of the beer and as such relates to the Si extracted from the grist