Comparison of the inactivation kinetics of pectin methylesterases from carrot and peach by high-pressure carbon dioxide

详细信息    查看全文

• 作者：Linyan Zhou ; Yan Zhang ; Xiaosong Hu ; Xiaojun Liao ; Jinfeng He
• 关键词：High-pressure carbon dioxide ; Pectin methylesterase ; Inactivation ; A fractional-conversion model
• 刊名：Food Chemistry
• 出版年：2009
• 出版时间：15 July 2009
• 年：2009
• 卷：115
• 期：2
• 页码：449-455
• 全文大小：335 K

文摘

The inactivation of pectin methylesterases (PMEs) from carrot and peach in buffer by high-pressure carbon dioxide (HPCD) at 55 °C was investigated. The two PMEs were effectively inactivated by HPCD, their residual activity (RA) decreasing with increasing pressures. The RA of the two PMEs exhibited a fast decrease firstly and reached a constant after a prolonged treatment time; their inactivation kinetics was adequately modelled by a fractional-conversion model. The non-zero RA(A_∞)of the two PMEs was 6–7 % , with increasing pressures the kinetic rate constant, k, increased and the decimal reduction time, D, decreased for the HPCD-labile fraction of the two PMEs. The labile fraction of carrot PME was more susceptible to HPCD than that of peach PME; the activation volume, V_a, and Z_P (the temperature increase needed for a 90 % reduction of D) was −1079.37 cm³/mol and 5.80 MPa for carrot PME, and −130.51 cm³/mol and 48.31 MPa for peach PME.