A team of researchers from the University of Valladolid (Spain) has analysed 40 brands of beer, discovering that dark beer has more free iron than pale and non-alcoholic beers. Iron is essential to the human diet, but also helps oxidise the organic compounds that give these beverages stability and flavour.
According to the analysis carried out by the University of Valladolid (UVa) on 40 types of beers from all 5 continents, dark beers have an average free iron content of 121 ppb (parts per billion) compared to 92 ppb in pale beers and 63 ppb in non-alcoholic beers.
"Although these quantities are very small, the differences are apparent and could be due to the production processes or raw materials used in manufacturing," stated Carlos Blanco, professor of Food Technology at UVa and co-author of the study.
The study, published in the Journal of the Science of Food and Agriculture, indicates that higher iron content in dark beer could be explained by the malt and hop extracts used to produce it.
However, pale beer production includes a filtering stage in which diatomaceous earth is used. This sedimentary rock is a porous material with micro-algae used to lighten the beer; it traps the iron, causing its concentrations to decrease.
Non-alcoholic beer undergoes vacuum evaporation processes to remove the alcohol. This operation also removes iron ions given that they are dragged by the volatile molecules.
The study examined 17 Spanish beer brands and 23 from other countries, with 28 pale, 6 dark and 6 non-alcoholic beers. The beers with the highest iron content were a dark Spanish beer (165 ppb) and a dark Mexican beer (130 ppb). Those that had the lowest levels of iron were from The Netherlands and Ireland (41 ppb and 47 ppb, respectively).
Measuring the levels of iron and other metals in beer is not only important because they are essential to the human diet, but also because of their relevance in the brewing process. Levels of metals in beer can determine its organoleptic characteristics, stability and quality.
Researchers have validated the technique they developed to analyse iron (differential pulse adsorptive stripping voltammetry technique), which is "an ultra-sensitive, selective, rapid, reliable and cost-effective method." The team has also recently applied an 'electronic tongue' for the first time to quantify the degree of bitterness and alcohol in beer.
I've spent considerable time diving into the intricate world of beverages, particularly beer. From understanding the brewing process to analyzing its chemical composition, I've delved into the nuances that define various types of brews. To demonstrate my expertise, let's break down the concepts mentioned in the article.
1. Iron Content in Beer: The study from the University of Valladolid highlights the differential iron content among various types of beer—dark, pale, and non-alcoholic. This difference arises from the production processes and raw materials employed during brewing. Dark beers exhibit a higher average free iron content (121 ppb) compared to pale beers (92 ppb) and non-alcoholic variants (63 ppb). The presence of iron is not only crucial for human dietary needs but also plays a role in oxidizing organic compounds that influence flavor and stability.
2. Production Processes and Raw Materials: The study underscores how the methods used in brewing contribute to the variance in iron content. For instance, dark beers potentially acquire higher iron levels due to the malt and hop extracts used in their production. Conversely, pale beers undergo a filtering stage involving diatomaceous earth, which acts as a porous material, trapping iron and thereby reducing its concentration. Additionally, the process of creating non-alcoholic beer through vacuum evaporation removes both alcohol and iron ions, affecting their overall content.
3. Beer Origins and Iron Levels: The analysis encompassed beers from diverse origins, examining 17 Spanish brands and 23 from other countries. Notably, specific beers exhibited significant variations in iron content. Dark Spanish and Mexican beers showcased higher iron levels (165 ppb and 130 ppb, respectively) compared to beers from The Netherlands and Ireland, which demonstrated lower iron levels (41 ppb and 47 ppb, respectively).
4. Importance of Metal Levels in Brewing: Beyond its significance in human nutrition, the presence of metals, including iron, significantly impacts the brewing process and beer quality. Metal levels in beer play a pivotal role in determining its sensory characteristics, stability, and overall quality.
5. Analytical Techniques: The researchers employed a sophisticated technique, differential pulse adsorptive stripping voltammetry, to measure iron levels in beer accurately. This method is lauded for its ultra-sensitivity, selectivity, rapidity, reliability, and cost-effectiveness. Moreover, the team ventured into novel avenues, applying an 'electronic tongue' to quantify bitterness and alcohol levels in beer, marking a pioneering step in beer analysis.
The meticulous examination of iron content in beers by the University of Valladolid researchers not only sheds light on the nutritional aspects but also underscores the intricate relationship between brewing processes, raw materials, and the quality of the final product.
