ANALYSIS OF THERMAL INACTIVATION KINETICS OF MEMBRANE-BOUND POLYPHENOL OXIDASES AND PEROXIDASES FROM METROXYLON SAGU

作者：Onsa Galila Hassan; Abdul Hamid Azizah; Selamat Jinap; Bakar Jamilah; Manap Mohd Yazid; Bin Saari Nazamid^*

来源：Journal of Food Biochemistry, 2011, 35(3): 819-832.

DOI：10.1111/j.1745-4514.2010.00419.x

Thermal inactivation kinetics for the purified membrane-bound polyphenol oxidases (mPPOs) and peroxidases (mPODs) isolated from Metroxylon sagu were analyzed. Each isoenzyme was treated at different time-temperature combinations in the range of 0-70 min and 20-70C. Thermal inactivation rates constant (k) at 70C for mPOD-I (72.9 x 10(-3)/min) and mPOD-II (97.9 x 10(-3)/min) were lower than that of mPPO-I (379.7 x 10(-3)/min) and mPPO-II (138.1 x 10(-3)/min). The activation energy for inactivation of mPPO-I (32.94 kcal/mol) and mPPO-II (40.34 kcal/mol) was lower compared with mPOD-I (45.77 kcal/mol) and mPOD-II (40.62 kcal/mol). The enthalpy values for mPOD-I (45.08 kcal/mol) and mPOD-II (39.94 kcal/mol) were higher than those of mPPOs (mPPO-I, 32.26 kcal/mol; mPPO-II, 39.66 kcal/mol). This result implies that both mPOD-I and mPOD-II are more thermostable.

• 出版日期2011-6