biodieselproductionThe stoichiometric ratio for the transesterification reactionrequires only 3 mol of alcohol and 1 mol of TAGs to yield 3 mol offatty acid ester and 1 mol of glycerol. A higher molar ratio of alco-hol to TAGs often promotes the transesterification reaction [23].However, methanol serves as reaction substrate for biodiesel pro-duction, and it is harmful to proteins in excessive proportions [41],in particular when it is insoluble in the reaction mixture (it formsan emulsion, and the size of the droplets depends on the inten-sity of stirring) [17]. Therefore, the methanol concentration (molarratio of methanol to oil) was varied from 1:1 to 5:1 to investigateits effect on the biodiesel yield. As seen in Fig. 7b, with an increas-ing molar ratio of methanol to oil from 1:1 to 4:1, the biodieselyield increased from 20.74% to 46.65% of the maximal conversionrate