Free iron in pale, dark and alcohol-free commercial lager beers

Abstract

The results point out that dark beers keep the highest free iron concentrations, which may be related to the highest amounts of minor ingredients in dark beers. Meanwhile, alcohol-free beers present the lowest free iron concentrations. Some discussion is presented regarding the basis of the free and complexed iron in beer and its participation as an essential element in the human diet.

The role of lager beer yeast in oxidative stability of model beer

“…Both the copper and iron ion concentrations detected in the model beer were comparable to those reported earlier (Wyrzykowska et al. 2001; Pohl and Prusisz 2010; Sancho et al. 2011).…”

“…In the model wort used in this study, the iron concentration is higher (600-815 lg l )1 ), yet the copper concentration is in the interval reported by Zufall and Tyrell (25-30 lg l )1 ) ( Table 3). Both the copper and iron ion concentrations detected in the model beer were comparable to those reported earlier (Wyrzykowska et al 2001;Pohl and Prusisz 2010;Sancho et al 2011).…”

Iron migration from undamaged and dented juice tinplate cans

“…Besides the health issues, iron contamination may adversely affect the organoleptic properties of the beverage. In fact, iron contamination was already shown to affect the sensory qualities of a variety of liquid foods, including beverages, as corrosion products of steel, especially iron salts, caused loss of odour as well as development of astringent, metallic or bitter tastes. For drinking water, the US Environmental Protection Agency (EPA) suggests that iron levels should remain below 0.3 mg L −1 , to avoid unpleasant tastes, odours or colours…”

Prediction of the ageing of commercial lager beer during storage based on the degradation of iso-α-acids

“…The dependence of the isomerisation reaction on temperature has been studied using the Arrhenius equation and differences in activation energies for the formation of trans-and cis-isomers were supplied, the activation energy for the formation of trans-iso-α-acids being approximately 9 kJ mol −1 lower than that for cis-iso-α-acids. 25 The chemical properties of humulone derivates 8,9,26,27 and the aluminium and iron content in beer have been analysed by us in previous studies; 28,29 an electronic tongue was even developed for the analysis of beer bitterness. 30 The present work has been undertaken to study degradation as related to changes in isoα-acids by monitoring trans-iso-α-acids quantitatively by using high-performance liquid chromatography (HPLC) in order to trace temperature-related alterations in the profiles of the iso-α-acids.…”

“…The chemical properties of humulone derivates and the aluminium and iron content in beer have been analysed by us in previous studies; an electronic tongue was even developed for the analysis of beer bitterness . The present work has been undertaken to study degradation as related to changes in iso‐ α ‐acids by monitoring trans ‐iso‐ α ‐acids quantitatively by using high‐performance liquid chromatography (HPLC) in order to trace temperature‐related alterations in the profiles of the iso‐ α ‐acids.…”