Anwar, S: Microencapsulation of Fish Oil Using Spray Granula

The stability of microencapsulated fish oil prepared using various drying methods is investigated. In the preliminary study, two production processes, i.e., spray granulation (SG) and SG followed by film coating (SG-FC) are examined and compared. First, three types of fish oil (10/50, 33/22, and 18/12) based on the ratios of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are used in the SG process. Each type of fish oil was emulsified with soybean soluble polysaccharide (SSPS) and maltodextrin to produce 25% oil powders. Second, a 15% film coating of hydroxypropyl betacyclodextrin (HPBCD) is applied to the SG granules. The powder stability against oxidation is examined by measurement of peroxide values (PV) and GC-headspace propanal after 6- weekÆs storage at room temperature (¿ 21 ¿C) and at 3 - 4 ¿C. The results show that the coated powders have lower stability than uncoated powders and this indicates that the film coating by HPBCD ineffectively protected the fish oil as the coating process might have induced further oxidation. In the main research, emulsions of 33/22 fish oil are prepared with four combinations of matrices and microcapsules are produced by SG, spray drying (SD), and freeze drying (FD). The objective is to identify the most critical factors which determine powder stability and to further examine the superiority of the SG process compared to other drying processes. Oxidation parameters and analytical methods remain the same as in the preliminary study, but the storage time is extended to 8 weeks. The best matrices are a combination of 10% (w/w) SSPS and 65% (w/w) OSA-starch. Microencapsulation of 620 mg/g fish oil with these coating materials then dried by SG is able to produce fish oil powder having a very low propanal content and with a shelf life of five weeks at ¿ 21 ¿C. The ability of SSPS to form thick membranes at the oil/water interface and the role of both matrices to stabilize emulsion by steric repulsion are critical to