Efficient and Response Surface Optimized Aqueous Enzymatic Extraction of Camellia oleifera (Tea Seed) Oil Facilitated by Concurrent Calcium Chloride Addition

This paper reports an efficient aqueous enzymatic extraction (AEE) method for Camellia oleifera seed oil with the aid of response surface analysis. A maximum oil recovery of similar to 93.5% was obtained when a 2-step AEE process was performed using 0.80% cellulase (v/w) solution at pH 6.0 maintained at 50 degrees C for 1 h followed by a solution of 0.70% Alcalase (R) with pH 9.2 at 57 degrees C for 4.1 h. It was found that the addition of Ca2+ during the proteolysis stage improved the free oil yield from similar to 62.1 to similar to 86.6%. This was attributed to the removal of tea saponins, cross-linkage of anionic polysaccharides, and destabilization of cream emulsion by Ca2+. This was verified by decreased tea saponin and polysaccharide levels in the cream emulsion and bulk solution as well as lowering of the emulsion fraction. It was determined that addition of CaCl2 solution in continuous flow to the proteolysate is superior to one-time or batch addition in inhibiting emulsion formation. The addition of CaCl2 may provide a means of replacing the more laborious, time-consuming demulsification process otherwise required.