Volume 9
Issue 1
Food Science and Technology
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Available Online: http://www.ejpau.media.pl/volume9/issue1/abs-26.html
RELEASE OF FREE FERULIC ACID AND FERULOYLATED ARABINOXYLANS FROM BREWERY’S SPENT GRAIN BY COMMERCIAL ENZYME PREPARATIONS
Dominik Szwajgier, Zdzisław Targoński
Department of Food Technology and Storage,
Lublin Agricultural Academy, Poland
ABSTRACT
Feruloylated arabinoxylans, obtained after enzymatic hydrolysis of arabinoxylans present in cereal by-products of food industry, can become a very attractive group of natural antioxidants that can be supplemented to human diet. In “in vitro” models, feruloylated arabinoxylans are more effective antioxidants towards low density lipoproteins oxidation and DPPH* free radicals “scavengers” than free ferulic acid. One possible way of obtaining bulk amounts of feruloylated arabinoxylans from industrial by-products (brewery’s spent grain, sugar beet pulp, wheat bran) is application of purified enzymes, xylanase and ferulic acid esterase, but this method is expensive. Another way of obtaining feruloylated arabinoxylans in industrial quantities is application of commercial enzyme preparations possessing many enzymatic activities towards non-starch polysaccharydes. In presented study, five commercial enzyme preparations were used in order to release feruloylated arabinoxylans from brewery’s spent grain: Celluclast, Viscozyme, Shearzyme, Cereflo and Ultraflo. All five enzyme preparations effectively released water-soluble esterified ferulic acid and free ferulic acid from brewery’s spent grain. Application of enzyme preparation Celluclast resulted in the highest yield of feruloylated arabinoxylans and in the lowest yield of free ferulic acid among all five preparations used, probably due to the lack of ferulic acid esterase activity in Celluclast. Enzyme preparations Viscozyme and Shearzyme very effectively released feruloylated arabinoxylans as well as free ferulic acid from brewery’s spent grain. The thermostabilities of xylanases in Viscozyme and Shearzyme were evaluated and attempt to partly inactivate ferulic acid esterases was made. It was proved, that heating of preparations Viscozyme and Shearzyme at 50°C prior addition to brewery’s spent grain resulted in decreased levels of free ferulic acid in solutions, whereas only a moderate decrease of feruloylated arabinoxylans concentrations occurred. In conclusion, it can be stated that enzyme preparations possessing except xylanase activity also ferulic acid esterase activity and other non-starch polysaccharides' hydrolases activities can be effectively used in order to obtain feruloylated arabinoxylans from brewery’s spent grain.
Key words: brewery’s spent grain, ferulic acid, xylanase, ferulic acid esterase, enzyme preparations.
Dominik Szwajgier
Department of Food Technology and Storage,
Lublin Agricultural Academy, Poland
Skromna 8, 20-704 Lublin, Box 158, Poland
ph. (48 81) 444 63 10
fax (48 81) 444 63 11
email: dszwajgier@hotmail.com
Zdzisław Targoński
Department of Food Technology and Storage,
Lublin Agricultural Academy, Poland
Skromna 8, 20-704 Lublin, Box 158, Poland
ph. (48 81) 444 63 10
fax (48 81) 444 63 11
Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.