Improvement in Storage Stability of Danmooji (Salted Radish) by High Hydrostatic Pressure and Heat Treatment

초고압과 열처리를 통한 단무지의 저장성 향상

  • Kim, Byong-Ki (Department of Food Engineering, Dankook University) ;
  • Hong, Kwan-Pyo (Department of Biotechnology and Bioproduct Research Center, Yonsei University) ;
  • Park, Ji-Yong (Department of Biotechnology and Bioproduct Research Center, Yonsei University)
  • 김병기 (단국대학교 식품공학과) ;
  • 홍관표 (연세대학교 생명공학과 및 생물산업소재연구센터) ;
  • 박지용 (연세대학교 생명공학과 및 생물산업소재연구센터)
  • Published : 1998.02.01

Abstract

This study was conducted to evaluate the storage stability of danmooji(salted radish) treated with high hydrostatic pressure $(300{\sim}686\;MPa)\;and\;heat\;(55^{\circ}C)$. Danmooji pressurized at 500 MPa and 686 MPa for 5 min showed $4{\sim}6log-cycle$ reductions in total microorganism, while danmooji heated at $55^{\circ}C\;for\;2\;hr\;showed\;3{\sim}5log-cycle$ reductions. However, danmooji pressurized at 300 MPa for 5 min showed a 2 log-cycle reduction, indicating that pressurization at lower than 300 MPa is insufficient for sterilization. After pressurized at 300 MPa, 500 MPa and 686 MPa for 5 min, pectinesterase (PE) activity of danmooji was increased by approximately 35%, 76% and 64%, respectively; and polygalacturonase (PG) activity of danmooji was increased by 109%. 163% and 120%, respectively. After heated at $55^{\circ}C$ for 2 hr, PE and PG activities of danmooji were increased by 18% and 200%, respectively. This indicates that PE in danmooji was more activated bypressure than heat, while PG was mostly activated by heat. Pressurized and heat-treated danmooji had higher hardness than control and maintained its hardness during storage at $30^{\circ}C$.