Effect of Bean Water Concentration and Incubation Time on Amylase Activity and Physicochemical Characteristics of Yukwa Paste

콩물 농도 및 숙성 시간이 Amylase 의 활성과 유과 반죽의 특성에 미치는 영향

  • Sohn, Kyung-Hee (Department of Food and Nutrition, Yonsei University) ;
  • Jo, Mi-Na (Department of Food and Nutrition, Yonsei University) ;
  • Jeon, Hyeong-Ju (Department of Food and Nutrition, Seoil College) ;
  • Park, Jin (Department of Food and Nutrition, Yonsei University) ;
  • Joo, Myung-Sook (Department of Food and Nutrition, Yonsei University)
  • 손경희 (연세대학교 식품영양학과) ;
  • 조미나 (연세대학교 식품영양학과) ;
  • 전형주 (서일대학 식품영양과) ;
  • 박진 (연세대학교 식품영양학과) ;
  • 주명숙 (연세대학교 식품영양학과)
  • Published : 2001.06.30

Abstract

${\alpha}-amylase$ activities of bean water was not significantly influenced by bean water concentrations but they were remarkably influenced by different temperatures and substrates. ${\alpha}-amylase$ activities of bean water on cooked starch were significantly higher than those on raw starch. ${\beta}-amylase$ and glucoamylase activities in 14% bean water were significantly higher than those in 7% bean water. Yukwa paste is glutinous rice flour paste. Bean water was added to Yukwa paste by 0, 7, 14% and incubated 0, 3, 6, 9, 12 hours at $60^{\circ}C$. The pH of Yukwa paste increased with bean water concentration and decreased with the incubation time. The viscosity decreased with bean water concentration and incubation time. The ruducing sugar content of Yukwa paste increased with bean water concentration and incubation time. The changes of reducing sugar content in cooked Yukwa paste were much higher than those in the raw one. ${\alpha},\;{\beta}-amylase$glucoamylase activities of Yukwa paste also increased with bean water concentration, and their activities were much higher on the cooked glutinous rice flour than those on the raw one. The SEM observation on the freeze-dried flour of Yukwa paste showed breakdown of amylopectin structure by addition of bean water in the paste.

Keywords

Yukwa;amylase;bean water concentration;incubation time;SEM