The crude roselle oil was obtained from Payakkaram Temple inSuphanburi. All chemicals used in the experiments, such asmethanol, potassium hydroxide, and n-heptane, were of analytical reagent (AR) grade.The methyl esters such as methyl heptadecanoate, methyl esters of palmitic, stearic, oleic, linoleic, and linolenicacids were standard for GC.
2.2. Alkali-catalyzed transesterificationIn this study, transesterification of crude roselle oil with methanol via base (KOH) catalysis was carried out in a laboratory-scale
setup.