Effects of Particle Size of Sucrose Suspensions and Pre-incubation of Enzymes on Lipase-Catalyzed Synthesis of Sucrose Oleic Acid Esters
Ye, R, D. G. Hayes, and R. Burton.  2015.  American Oil Chemists’ Society 106th Annual Meeting, Orlando, 3-6 May 2015.  (invited)

The effects of high-speed homogenization, high-intensity ultrasound, and their combination were evaluated for the reduction of the particle size of sucrose crystals to enhance solvent-free lipasecatalyzed synthesis of sucrose oleate at 65 °C. The combination of homogenization and ultrasound greatly decreased the particle size of suspended sucrose crystals in mixtures of oleic acid/ sucrose oleate (86 wt% monoester and 14 wt% diester) at a ratio of 90/10 w/w from 88 to 18 μm. The suspensionbased medium was charged to a stirred tank bioreactor that also contained immobilized lipase from Rhizomucor miehei or Candida antarctica (Lipozyme®IM and Novozym® 435, respectively; Novozymes, Franklinton, NC, USA), that was pre-incubated in oleic acid for several different temperatures (23–60 °C), durations (4–24 h), and stir rates (50–400 rpm, (radius of 3 cm), prior to use. The optimal performance was achieved using C. antarctica lipase (83.3 wt% ester, consisting of 46 wt% monoester) in the presence of molecular sieves (18 wt%). The low water concentration (~0.12 wt%) did not affect the activity of C. antarctica lipase.