In the present study, response surface methodology involving central composite design was applied
to optimize reaction parameters of biodiesel production from Tra (Pangasius hypophthalmus) and
Basa (Pangasius bocourti) catfish oil during the microwave-assisted single-step transesterification
process. Second-order polynomial models of the microwave-assisted method with acetone (MW-A)
and isopropanol (MW-I) co-solvent were used to predict the biodiesel yield and the coefficient of
determination (R2) was found to be at 0.9926, and 0.9891, respectively. Research results demonstrated
that isopropanol had similar effects to acetone on transesterification yields. The optimum biodiesel
yield was calculated as 99.05% (MW-A) and 98.96% (MW-I) from the models with the following
reaction conditions: methanol-to-oil molar ratio of 5.60 (MW-A) and 5.66 (MW-I), KOH concentration
of 1.04 wt% (MW-A) and 1.00 wt% (MW-I), the reaction temperature of 53.20 ◦C (MW-A) and 53.59
◦C (MW-I), the reaction time of 94.43 s (MW-A) and 93.27 s (MW-I), and co-solvent of 24.20 wt%
(MW-A) and 22.73 wt% (MW-I). The results of biodiesel yield under optimal conditions have proved
that the regression models agreed with the experimental data. Furthermore, the properties of catfish
oil biodiesel produced under the optimum conditions were characterized and found to agree with the
EN 14214 standard specifications.