Optimization of Technology for Virgin Coconut Oil Microencapsulation by Response Surface Methodology

Virgin coconut oil (VCO) microencapsulation technology was developed by spray drying method and the technology was optimized by response surface methodology. Soybean protein isolates (SPI) and maltodextrin were used as wall materials, sucrose esters (SE) and glycerin monostearate (GMS) were used as emulsifiers. Plackett-Burman(PB) design and Box-Behnken (BB) design were applied to screen and optimize influential factors in the process of microencapsulaiton effcency(MEE). The PB design and statistic analysis showed that homogenization pressure, emulsifying time and inlet air temperature were three key factors in this process. Other factors were identified that the total solids concentration was 25%, the ratio of wall materials and core materials was 1:3, the ratio of maltodextrin and SPI was 1:1, the dosage of sucrose esters was 0.5%, and the emulsifying temperature was 40 degrees C. The quadratic model for three significant factors was established with the MEE as the target response by BB design and response surface analysis. The optimum conditions were as follows: emulsifying time was 60min, homogenization pressure was 40MPa and the inlet air temperature was 177 degrees C. The MEE of microencapsulaiton virgin coconut oil (MEVCO) can reached 65.89% under the optimal conditions.