Process Optimization Using Response Surface Design and Pilot Plant Production of Dietary Diacylglycerols by Lipase-Catalyzed Glycerolysis

Abstract

Two approaches to shift the acylglycerol equilibrium were tested as follows: addition of monoacylglycerols and lowering of the temperature. None of these approaches were able to shift the equilibrium toward higher diacylglycerol (DAG) contents. The glycerolysis reaction was optimized with five factors using response surface methodology. Evaluation of the resulting model enabled the determination of optimal reaction conditions for glycerolysis aiming at high DAG yield. However, verification of the model showed that the model was unable to take the molecular equilibrium into account but it provided good insight in how process settings can be chosen to, for example, minimize production costs. Optimal conditions were found to be the following: no extra water, low content of glycerol (molar ratio of 2), temperature of 60-65 degrees C, 4-5 h reaction time, and only 5 wt % lipases. Up scaling of the glycerolysis process was performed and revealed that scale-up to a 20 kg production in a pilot plant batch reactor was possible with a similar DAG yield (60 wt %) as in lab scale. Purification of DAG oil using batch deodorization and short path distillation yielded 93 wt % pure DAG oil.

Process Optimization of Enzyme Catalyzed Production of Dietary Diacylglycerol (DAG) Using TLIM as Biocatalyst

“…The yield of DAG increased progressively and reached at maximum value at 59.8 after 5 h of reaction. Janni Brogaard 19 proposed the optimal time for 60 production of DAG oil in lab scale to be 4-5 h using non-specific Novozyme 435 as biocatalyst from sunflower oil by response surface design. Thereafter the dissociation of DAG and regeneration of TAG led to a decrease in the ultimate yield of DAG.…”

“…Anti-obesity and hypocholesterolemic effect of DAG-rich rice bran oil was evaluated subsequently due to the presence of natural antioxidants such as oryzanol, tocopherol, tocotrinol and some other micronutrients 18 . Production of DAG-rich sunflower oil using Novozyme-435 is an established fact 19 .…”

Enzyme activation using dynamic manipulation of process variables.

“…The authors Coteron, A. et al [25], Kristensen, J.B. et al [15] and Paroul, N. et al [16], claim that temperature has three important roles in this type of reaction. The first is the decrease of viscosity with increasing temperature of the reaction mean, which provides better miscibility and reduced diffusional limitations.…”

“…The first is the decrease of viscosity with increasing temperature of the reaction mean, which provides better miscibility and reduced diffusional limitations. The second role is the influence on the condition of optimum temperature of the enzyme [15,16,25]. Finally, the third role is increased cavitation that influences emulsion formation [26,27].…”

“…Usually, these studies conclude that maximal response occurs at the highest level studied [10][11][12][13]. Additionally, it was verified that the process is not always controlled by the same variables, even for similar studies with similar levels [9,[14][15][16][17].…”