Preparation of swollen starch granules from heat-moisture treated cassava starch and its oil absorption capacities

Encapsulation/ entrapment of avogado oil in heat-moisture treated (HMT) and swollen HMT cassava starch granules by absorption under various treatments and different incubation conditions was investigated. The microcapsules were basically prepared by incubating 100 g of starch with 10 g of avogadro oil, washing with petroleum ether to remove excess oil, and then drying to get dried oil powders. The oil loading of HMT was 1.99%, g/ 100 g microcapsules and encapsulation efficiency (EC) was 44.60%. Swollen HMT cassava starches were prepared by controlled heating of starch suspensions at sub-gelatinization temperatures; subsequently, freezing was conducted to stabilize the structure of the swollen HMT. The EC of swollen HMT starch was increased to 17.03%. In addition, freezing of the swollen starch at -18 ºC for 3 h prior to drying could increase the EC to 23.96%. Incubation condition also affected the EC, i.e., warming the oil to 50 °C before kneading with starch and incrasing the incubation temperature to 50 ºC can raise the oil loading to 5.88% and the EC to 69.91%. The microcapsules obtained appeared as fine white powders, similar to the native cassava starch but had slightly higher moisture.