A new study suggests that beer is a significant source of dietary silicon, a key ingredient for increasing bone mineral density. Researchers from the Department of Food Science & Technology at the University of California, Davis studied commercial beer production to determine the relationship between beer production methods and the resulting silicon content, concluding that beer is a rich source of dietary silicon. Details of this study are available in the February issue of the Journal of the Science of Food and Agriculture, published by Wiley-Blackwell on behalf of the Society of Chemical Industry.
"The factors in brewing that influence silicon levels in beer have not been extensively studied" said Charles Bamforth, lead author of the study. "We have examined a wide range of beer styles for their silicon content and have also studied the impact of raw materials and the brewing process on the quantities of silicon that enter wort and beer."
Silicon is present in beer in the soluble form of orthosilicic acid (OSA), which yields 50% bioavailability, making beer a major contributor to silicon intake in the Western diet. According to the National Institutes of Health (NIH), dietary silicon (Si), as soluble OSA, may be important for the growth and development of bone and connective tissue, and beer appears to be a major contributor to Si intake. Based on these findings, some studies suggest moderate beer consumption may help fight osteoporosis, a disease of the skeletal system characterized by low bone mass and deterioration of bone tissue.
The researchers examined a variety of raw material samples and found little change in the silicon content of barley during the malting process. The majority of the silicon in barley is in the husk, which is not affected greatly during malting. The malts with the higher silicon contents are pale colored which have less heat stress during the malting process. The darker products, such as the chocolate, roasted barley and black malt, all have substantial roasting and much lower silicon contents than the other malts for reasons that are not yet known. The hop samples analyzed showed surprisingly high levels of silicon with as much as four times more silicon than is found in malt. However, hops are invariably used in a much smaller quantity than is grain. Highly hopped beers, however, would be expected to contain higher silicon levels.
No silicon was picked up from silica hydrogel used to stabilize beer, even after a period of 24 hours and neither is there pick up from diatomaceous earth filter aid.
The study also tested 100 commercial beers for silicon content and categorized the data according to beer style and source. The average silicon content of the beers sampled was 6.4 to 56.5 mg/L.
"Beers containing high levels of malted barley and hops are richest in silicon," concludes Dr. Bamforth. "Wheat contains less silicon than barley because it is the husk of the barley that is rich in this element. While most of the silicon remains in the husk during brewing, significant quantities of silicon nonetheless are extracted into wort and much of this survives into beer."
Article: "Silicon in Beer and Brewing." Troy R. Casey and Charles W. Bamforth. Journal of the Science of Food and Agriculture Published Online: February 8, 2010 (DOI: 10.1002/JSFA.3884); Print Issue Date: February 2010
This study is published in Journal of the Science of Food and Agriculture. Media wishing to receive a PDF of this article may contact email@example.com.
The Journal of the Science of Food and Agriculture publishes peer-reviewed original research, reviews, mini-reviews, perspectives and spotlights, with particular emphasis on interdisciplinary studies at the agriculture/ food interface. This international journal covers fundamental and applied research, including: food, health and nutrition, food science and technology, biotechnology, molecular biology, biochemistry, food safety, materials and processing, agriculture production, utilization, and environment, as well as sensory and consumer sciences. The Journal of the Science of Food and Agriculture is published by Wiley-Blackwell on behalf of the Society of Chemical Industry (SCI). For more information, please visit www.interscience.wiley.com/jsfa.
The Society of Chemical Industry (SCI) is a unique international forum where science meets business on independent and impartial ground. Anyone can join the Society, which offers a chance to share information, ideas and new innovations between sectors as diverse as food and agriculture, pharmaceuticals, biotechnology, environmental science and safety. Originally established in 1881, SCI is a registered charity with individual Members in over 70 countries. For further information on SCI activities and publications, please visit: www.soci.org
Wiley-Blackwell is the international scientific, technical, medical, and scholarly publishing business of John Wiley & Sons, with strengths in every major academic and professional field and partnerships with many of the world's leading societies. Wiley-Blackwell publishes nearly 1,500 peer-reviewed journals and 1,500+ new books annually in print and online, as well as databases, major reference works and laboratory protocols. For more information, please visit www.wileyblackwell.com or www.interscience.wiley.com.
Journal of the Science of Food and Agriculture