Abstract
Pilot production of specifically structured lipids by Lipozyme
IM-catalyzed interesterification was carried out in a continuous
enzyme bed reactor without the use of solvent. Medium chain
triacylglycerols and oleic acid were used as model substrates.
Response surface methodology was applied to optimize the reaction
system with four process parameters, these being volume flow rate,
water content in the substrates, reaction temperature and
substrate ratio. The incorporation of acyl donors, product yields
and the content of diacylglycerols were measured as the model
responses. Enzyme activity was not identical for the sequential
experiments in the same enzyme bed due to the deactivation of the
Lipozyme IM. Therefore, the results were normalized based on
enzyme deactivation models. Well-fitting quadratic models were
obtained after normalizing the data for the incorporation of oleic
acid and the production of mono-incorporated and di-incorporated
structured lipids with multiple regression and backward
elimination. The coefficient of determination (R2) for the
incorporation was 0.93, and that for the di-incorporated products
was 0.94. The optimal conditions were flow rate, 2 ml/min;
temperature, 65 °C; substrate ratio, 5.5; and water content, 0.1%.
The production of diacylglycerols was not well correlated with any
of the parameters and the yield generally decreased with the
experimental sequence. This was due to the stoichiometric water in
the substrate mixture in the packed enzyme bed being complicated
by the water binding and absorption of the immobilized lipase. The
main effects of parameters were also examined and conclusions in
agreement with our previous results were made.
Original language | English |
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Journal | Fett/Lipid |
Volume | 101 |
Issue number | 6 |
Pages (from-to) | 207-213 |
Publication status | Published - 1999 |