Activities of Hydrolytic Enzymes in Barley Malts Prepared under Different Germination Conditions

발아조건별 당화용 엿기름의 분해효소 활성도

  • Mok, Chul-Kyoon (Department of Food and Bioengineering, Kyungwon University) ;
  • Lee, Young-Tack (Department of Food and Bioengineering, Kyungwon University)
  • 목철균 (경원대학교 식품생물공학과) ;
  • 이영택 (경원대학교 식품생물공학과)
  • Published : 1999.11.30

Abstract

Barley malts were prepared at 15, 18 and $21^{\circ}C$ for $3{\sim}6$ days, and assayed for ${\beta}-glucanase$, ${\alpha}-amylase$ and ${\beta}-amylase$ activities. ${\beta}-Glucanase$ activity increased markedly during earley germination and reached maximum at the 6th day of germination. ${\beta}-Glucanase$ activity in six-rowed barley malt was much higher than that in two-rowed malt. ${\beta}-Glucanase$ activity was associated with reduction in ${\beta}-glucan$ content during germination. ${\beta}-amylase$ activity was also considerably higher in two-rowed barley, and increased continuously during 6-day germination. ${\beta}-Amylase$ activity was the lowest at $15^{\circ}C$, the highest at $18^{\circ}C$, and intermediate at $21^{\circ}C$ of germination temperature. Considerable amount of ${\beta}-amylase$ was detected in ungerminated raw barley, and this enzymatic activity tended to increase during 6-day germination. Diastatic power, measure of starch-saccharifying enzyme, in six-rowed malt was $1.4{\sim}1.6$ fold higher than in two-rowed malt. Germination at $18^{\circ}C$ for $5{\sim}6$ days was suggested to be the optimum condition for manufacturing good quality malts, in terms of enhanced starch-degrading enzymatic activity.