The formation and hydrolysis of barley malt gel-protein under different mashing conditions

Saara Pöyri (Corresponding Author), M. Mikola, T. Sontag-Strohm, Anu Kaukovirta-Norja, Silja Home

Research output: Contribution to journalArticleScientificpeer-review

15 Citations (Scopus)

Abstract

The effect of oxidation and proteolysis on the amount of gel-protein aggregate was investigated both in vivo during mashing and in vitro. The oxidation of the free thiol groups of proteins to disulphide bridges during mashing appeared to be a good indicator of the formation of gel-protein aggregate. The pH optimum of the oxidation varied according to the isothermal mashing temperature. The results suggested that the oxidation of the thiol groups maybe a result of some kind of enzymatic activity. In vitro experiments showed that the proteolysis of the gel-protein aggregate was strongest at pH 5.0 and temperature denaturation occurred only at temperatures over 80°C. Mashing experiments on the other hand suggested that the proteolysis of the monomer subunits of gel-protein (i.e. B- and D-hordein) had a stronger effect on the final amount of the gel-protein aggregate than the hydrolysis of the aggregate.
Original languageEnglish
Pages (from-to)261-267
JournalJournal of the Institute of Brewing
Volume108
Issue number2
DOIs
Publication statusPublished - 2002
MoE publication typeA1 Journal article-refereed

Keywords

  • Gel-protein
  • hordein
  • hydrolysis
  • mashing
  • oxidation
  • proteolysis

Fingerprint Dive into the research topics of 'The formation and hydrolysis of barley malt gel-protein under different mashing conditions'. Together they form a unique fingerprint.

  • Cite this