1 The Exploitation of Lipase Selectivities
for the Production of Acylglycerols
R.M.M. Diks and J.A. Bosley
1.1 Introduction
Triglyceride modification using lipases nowadays is a well-known principle. During
the past 20 years, numerous papers have been published describing the production of
mono-, di- and triglycerides, as well as other lipid derivatives, mostly fatty acid
esters. Throughout the literature, many different types of lipases have been de-
scribed for enzymatic modification. Based on their specificity or selectivity these
lipases can be divided into three classes (Table 1):
1. Regio- or positional specific;
2. Fatty acid type specific;
3. Specific for a certain class of acylglycerols, i.e. mono-, di- or triglycerides.
The reactions catalyzed by these lipases include hydrolysis, glycerolysis, esterifica-
tion, acidolysis and interesterification. Using any of these reactions the aim is to
produce specific end products at highest yield and purity. Obviously careful selec-
tion of the process conditions, such as water activity, temperature or substrate com-
position is required. However, selection of the correct lipase with the most appro-
priate selectivity can also be of the highest importance in achieving commercially
interesting products. The following overview aims to highlight the exploitation of the
specificity of these lipases in the production of various acylglycerols.
It is important to realize that most process descriptions given below are generally
based on laboratory or bench-scale studies. Very few are run as full-scale commercial
processes, especially in relation to foods. This is mainly due to the high cost and
relatively low operational productivity of most of the lipases applied. The growing
ability to exploit the high selectivity of enzymes, yet retain mild processing condi-
tions means that interest in biocatalysis is expected to grow during the coming years.
Moreover, as a consequence of modern biotechnology, the cost of enzymes is likely
to fall, thus permitting wider economic application.
1.2 Free fatty acids
1.2.1 Nonselective production of free fatty acids
The simplest process involving lipases is hydrolysis of oils and fats. This reaction
actually reflects the natural function of lipases. However, only few lipases – all from
Candida rugosa– are actually able to completely hydrolyze triglycerides into gly-
Enzymesin LipidModification.Editedby UweT. Bornscheuer
Copyright 2000 Wiley-VCHVerlagGmbH& Co. KGaA,Weinheim.ISBN:3-527-30176-
