Ultrasound-Assisted, Base-Catalyzed, Homogeneous Reaction for Ferulic Acid Production from γ-Oryzanol

Table 2

The kinetics parameters of γ-oryzanol hydrolysis obtained by the heating method and the homogeneous system of Type A with assistance of ultrasonic irradiation.

Method of hydrolysis	Rate constant ( × 10^4 (min^−1))					Ea (kJ/mol)	ln A
	30°C	40°C	50°C	60°C	75°C
Heating method (kheat)^1	1.16	1.61	3.40	5.42	9.92	43.6	10.493
US 20kHz
(ksonic20)^2	2.33	3.04	4.10	5.96	—	26.1	4.2796
(ksonic20/kheat)^3	(2.00)	(1.88)	(1.21)	(1.10)
US 200 khz
(ksonic200)^4	1.67	2.29	4.08	5.54	—	34.9	7.4479
(ksonic200/kheat)^5	(1.44)	(1.42)	(1.20)	(1.02)

Reaction system of A20. Type A: consists of ethyl acetate/H₂O/ethanol. ¹Heating method (k_heat): rate constant of the heating method. ²Ultrasonic irradiation, 20 kHz, 50 W (k_sonic20). ³In parenthesis: ratio of k_sonic20 versus k_heat. ⁴Ultrasonic irradiation, 20 kHz, 50 W (k_sonic20). ⁵In parenthesis: ratio of k_sonic200 versus k_heat.