Response surface methodological study of esterification of lactic acid with palmitic acid catalyzed by immobilized lipases from Mucor miehei and porcine pancreas

Response surface methodology was employed to analyze the effects of importa nt process parameters such as lactic acid/palmitic acid (LA/PA) concentrati ons (X-s), enzyme/substrate (E/S) ratios (X-e) and incubation time (X-t) on the preparation of palmitoyl lactic acid using Mucor miehei lipase (MML) a nd por cine pancreas lipase (PPL), Experimental ester yields were found to be in good agreement with predictions. In the case of MML, the ester yield was found to increase with X-e and X-t and a maximum yield of 27 mM was obt ained at X-e = 128 activity units(AU)/mM of substrate, X-S = 64-74 mM and X -t = 72 h. In the case of PPL, the ester yield was found to increase with i ncreases in X-e and X-s. Optimum conditions for PPL were X-e = 35AU/mM, X-s = 85-90 mM and X-t = 72 h, at which the maximum ester yield of 15 mM was o btained.