FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

DOMINIK SZWAJGIER, ZDZISŁAW TARGOŃSKI

Title

Arabinoxylans from malt as a source of natural antioxidant ferulic acid and dietary fibre in beer

Abstract

Recently, a tendency is observed to replace synthetic antioxidants, which are added to food, by natural products containing the same substances. This paper deals with the role the ferulic acid, a main phenolic acid of barley and malt, plays in shaping the antioxidant potential of beer. There is also presented the current state of knowledge of the ferulic acid’s antioxidant activity measured under the in vitro and in vivo conditions. Furthermore, the paper contains a detailed description of the structure, functions, and technological significance of arabinoxylans and b-glucans under the processes of beer malting and brewing. If the amounts of free ferulic acid added to beer have low concentration rates, then, the ferulic acid is very stable, whereas the highly concentrated free ferulic acid amounts cause a very rapid decrease in the ferulic acid content. The antioxidant activity of ferulic acid in beer is similar to the antioxidant activity of (+)-catechin. However, (+)- catechin causes beer to haze at a concentration rate being much lower if compared with the ferulic acid. Therefore, the ferulic acid at higher concentration rates can positively impact the colloidal stabilization of beer. As an active antioxidant with one active site, the ferulic acid can block active sites of the haze-generating proteins and, in this way, make it impossible for (+)-catechin and its derivatives to access proteins in the sites with polyphenol bonds. Thus, the increased concentration rates of ferulic acid in beer in the form of combination with sugars can contribute to enhancing the health-promoting properties of beer alongside low outlays necessary to modify the beer manufacturing process, especially the mashing process.

Keywords

beer, ferulic acid, arabinoxylans, antioxidant activity

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