Inactivation of Pectinesterase in Citrus Juice by Supercritical Carbon Dioxide

초임계 이산화탄소에 의한 감귤쥬스 중 pectinesterase의 불활성화

  • Jwa, Hi-Kyung (Department of Food Science and Technology, Cheju National University) ;
  • Lim, Sang-Bin (Department of Food Science and Technology, Cheju National University) ;
  • Koh, Jeong-Sam (Department of Agricultural Chemistry, Cheju National University)
  • Published : 1996.08.30

Abstract

Citrus juice was treated with supercritical carbon dioxide $(SC-CO_{2})$ as an alternative to heat for pectinesterase (PE) inactivation to minimize undesirable changes in flavor, color and ascorbic acid loss caused by the current heat treatment, and the effect of temperature $(40,\;50,\;60^{\circ}C)$, pressure (138, 276 bar) and process time $(5{\sim}130\;min) $ on PE activity was determined. PE in temperature control samples was inactivated by 54% at $40^{\circ}C$ after 130 min, 84% at 50% after 60 min and 83% at $60^{\circ}C$ after 30 min treatment compared to the original juice. PE inactivation in $(SC-CO_{2})$ treated samples at 138 bar was 83% at $40^{\circ}C$ after 130 min, 88% at $50^{\circ}C$ after 20 min and 87% at $60^{\circ}C$ after 10 min. %PE inactivation due to pressure was higher at low temperature and lower at high temperature. Higher temperature, Pressure and longer process time resulted in higher %PE inactivation. Nonlinearity in the curves of PE inactivation at different temperatures and pressures indicated that at least two forms of PE existed in citrus juice with different stabilities.

Keywords

supercritical carbon dioxide;citrus juice;pectinesterase