title: Study of microwave effects on the lipase-catalyzed hydrolysis.
abstract: The effect of microwave heating on lipase-catalyzed reaction remains controversial. It is not clear whether the reaction rate enhancements are purely due to thermal/heating effects or to non-thermal effects. Therefore, quantitative mass spectrometry was used to conduct accurate kinetic analysis of lipase-catalyzed hydrolysis of triolein by microwave and conventional heating. Commercial lipases from Candida rugosa (CRL), Porcine Pancreas (PPL), and Burkholderia cepacia (BCL) were used. Hydrolysis reactions were performed at various temperatures and pH levels, along with various amounts of buffer and enzymes. Hydrolysis product yields at each time point using an internal-standard method showed no significant difference between microwave and conventional heating conditions when the reaction was carried out at the same temperature. CRL showed optimum catalytic activity at 37 °C, while PPL and BCL had better activities at 50 °C. The phosphate buffer was found to give a better hydrolysis yield than the Tris-HCl buffer. Overall results prove that a non-thermal effect does not exist in microwave-assisted lipase hydrolysis of triolein. Therefore, conventional heating at high temperatures (e.g., 50 °C) can be also used to accelerate hydrolysis reactions.
authors.affiliation: Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Department of Chemistry, Nizam College, Osmania University, Hyderabad, India.
authors.forename: P Muralidhar
authors.initials: PM
authors.lastname: Reddy
authors.affiliation: Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan.
authors.forename: C Shobha
authors.initials: CS
authors.lastname: Devi
authors.affiliation: Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan.
authors.forename: Po-Chi
authors.initials: PC
authors.lastname: Chang
authors.affiliation: Department of Chemistry, National Dong Hwa University, Hualien 97401, Taiwan. Electronic address: ypho@mail.ndhu.edu.tw.
authors.forename: Yen-Peng
authors.initials: YP
authors.lastname: Ho
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism; D016956:Burkholderia cepacia / Q000201:enzymology; D002175:Candida / Q000201:enzymology; D005656:Fungal Proteins / Q000378:metabolism; D006358:Hot Temperature; D006868:Hydrolysis; D008049:Lipase / Q000378:metabolism*; D013058:Mass Spectrometry; D008872:Microwaves; D019301:Oleic Acid / Q000032:analysis; D010179:Pancreas / Q000201:enzymology; D013552:Swine; D014304:Triolein / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D014304:Triolein; D019301:Oleic Acid; D008049:Lipase
keywords: Lipase-catalyzed reaction; Mass spectrometry; Microwave; Quantitative analysis; Triolein