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Appl Biochem Biotechnol (2013) 171:22732284
DOI 10.1007/s12010-013-0495-5
Anita ali & Katarina Pindri & Bruno Zeli
Received: 3 July 2013 /Accepted: 29 August 2013 /
Published online: 17 September 2013# Springer Science+Business Media New York 2013
Abstract Hexanal and hexanoic acid have number of applications in food and cosmetic industry because of their organoleptic characteristics. Problems like low yields, formation of unwanted byproducts, and large quantities of waste in their traditional production processes are the reasons for developing new production methods. Biotransformation in a microreactor, as an alternative to classical synthesis processes, is being investigated. Because conditions in microreactors can be precisely controlled, the quality of the product and its purity can also be improved. Biocatalytic oxidation of hexanol to hexanal and hexanoic acid using suspended and immobilized permeabilized whole bakers yeast cells and suspended and immobilized purified alcohol dehydrogenase (ADH) was investigated in this study. Three different methods for covalent immobilization of biocatalyst were analyzed, and the best method for biocatalyst attachment on microchannel wall was used in the production of hexanal and hexanoic acid.
Keywords Food additives . Hexanol oxidation . Hexanal . Hexanoic acid . Biocatalysis . Microreactor
Abbreviationsc concentration (mmol/dm3)
kd enzyme operational stability decay rate constant (1/h)
T temperature (C)t time (h)
V reactor volume (mm3)
V.A. volumetric activity (U/cm3)
X conversion (%) mass concentration (g/cm3)
wavelength (nm)
A. ali : K. Pindri : B. Zeli (*)
Faculty of Chemical Engineering and Technology, University of Zagreb, Maruliev trg 19, 10000 Zagreb, Croatiae-mail: [email protected]
A. alie-mail: [email protected]
K. Pindrie-mail: [email protected]
Bioproduction of Food Additives Hexanal and Hexanoic Acid in a Microreactor
2274 Appl Biochem Biotechnol (2013) 171:22732284
residence time (s) flow rate (mm3/min)
ADH alcohol dehydrogenaseAPTES 3-aminopropyltrietoxysilaneCTAB hexadecyltrimethylammonium bromidei inletNAD+ nicotinamide adenine dinucleotideNADH nicotinamide adenine dinucleotide hydrate
Introduction
Volatile C6- and C9-aldehydes and alcohols, such as hexanal, are the main contributors to the characteristic odor of plants. They are widely used as food flavors to reconstitute the fresh green odor of fruits and vegetables lost during processing [1]. Several processes for the production of natural chemicals that are based on fermentation, extraction from plants, and enzyme-catalyzed reactions have been described [24]. Another interesting component that could be used in the organic synthesis, perfume manufacturing, medicine etc. is hexanoic or caproic acid. In...