Fractionation and Quantitation of Oligopeptides in Beer and Wort. H. Yokata, H. Sahara, and S. Koshino, Brewing Research Laboratories, Sapporo Breweries Ltd., Shizuoka, Japan. J. Am. Soc. Brew. Chem. 51:0054, 1993.

Oligopeptides (mol wt < 1,000) in beer and wort were separated into four fractions (strongly acidic, acidic, neutral, and basic) using ion-exchange column chromatography and ultrafiltration. Their amounts were estimated from the increments of amino acids after acid hydrolysis. The oligopeptide content of the strongly acidic fraction was the highest among the four fractions. The amino acid composition of the oligopeptides suggested that oligopeptides in beer were derived from albumin, globulin, and hordein through proteolytic degradation, especially the strongly acidic oligopeptides from hordein. Oligopeptides accounted for approximately 20-30% of the total nitrogen in beer, and thus were higher in amount than were free amino acids. The reduction of the acidic oligopeptides was about 30% from worts to beers, whereas oligopeptides in the three other fractions were slightly reduced or remained almost unchanged.

Keywords: Amino acids, Beer, Oligopeptides, Peptides, Wort