Microencapsulation of lactase by W/O/W emulsion followed by complex coacervation: Effects of enzyme source, addition of potassium and core to shell ratio on encapsulation efficiency, stability and kinetics of release.

This study evaluated the technological viability of the formation of lactase microcapsules by coacervation (gelatin/gum arabic) containing potassium ions (cofactor). The impacts of the encapsulation and the cofactor on the enzyme properties obtained from Aspergillus oryzae and Kluyveromyces lactis were evaluated as a function of different pH values, temperatures, and storage times. The best microcapsules formed by coacervation showed good functional properties, such as low water activity (≤ 0.4) and particle size (≤ 93.52 µm), as well as high encapsulation efficiency (≥ 98.67%). The potassium ions were capable of reducing the flexibility of the polypeptide backbone, thereby increasing the stability of the enzyme. The microcapsules were also capable of increasing the stability of the enzyme under unfavorable pH values, high temperatures and during storage. An in vitro experiment showed that microcapsules were effective in the retention of about 90% of the enzyme in simulated gastric fluid, but as much as 95% of the enzyme can be released from the capsules in simulated intestinal fluid. The released enzyme retained 83% and 66% of the total enzymatic activity for the capsules produced with lactase from Kluyveromyces lactis and A. oryzae, respectively. These results are promising and demonstrated that these microcapsules are a promising technology to protect and deliver bioactive proteins during storage and delivery in the GI tract.