Natural flavour ester production by immobilized Candida cylindracea lipase in organic solvent

Creator: 

Gillies, Richard Bruce

Date: 

1987

Abstract: 

Production of natural flavour esters by lipase was studied. Lipase can catalyze ester formation when an organic solvent, capable of extracting the ester, is used as a bulk phase solvent. Candida cylindracea lipase, which shows broad substrate specificity and pH stability, was immobilized by adsorption to silica gel. Synthesis of ethyl butyrate was studied as a model. The immobilized lipase was shaken in n-heptane containing ethanol and butyric acid. Ester production rate was optimal around: pH 4, decreasing at higher pH values; 30°C, decreasing at higher temperatures; substrate concentration of 0.4 M ethanol and 0.25 M butyric acid. Enzyme hydration was found necessary for stable activity in repeated use. A variety of flavour esters was produced. Ethyl butyrate production was also evaluated in a packed column of immobilized lipase through which a solution of hexane containing substrate was recycled. With a solution volume to packed bed ratio of 3:1, a space velocity of 20h-1 was found to maximize ethyl butyrate production.

Subject: 

Esters -- Synthesis

Language: 

English

Publisher: 

Carleton University

Thesis Degree Name: 

Master of Science: 
M.Sc.

Thesis Degree Level: 

Master's

Thesis Degree Discipline: 

Biology

Parent Collection: 

Theses and Dissertations

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