Physicochemical properties of yogurt fortified with microencapsulated Sacha Inchi oil

Abstract

Yogurt can be fortified with polyunsaturated fatty acids such as Sacha Inchi oil (SO) whose stability can be improved by microencapsulation. The comparison on yogurt properties after addition of microcapsules with hydrophobic and hydrophilic wall materials is scare. The aim of this work was to compare physicochemical properties of yogurt during 30-day storage at 4 °C after fortifying with 1 g SO/100-g-yogurt in the unencapsulated or microencapsulated form. Freeze-dried SO microcapsules (FDSOMs) were prepared with hydrophobic zein, and spray-dried SO microcapsules (SDSOMs) were prepared with hydrophilic maltodextrin and modified starch. Yogurt samples had a desirable pH from 3.88 to 4.23 during storage and had a light-yellow appearance. Microcapsules were homogeneously distributed in the yogurt, while big oil droplets were observed for the unencapsulated SO. The addition of SO and microcapsule powders weakened the yogurt network, most significant for FDSOMs due to the most incompatible hydrophobic zein. Syneresis of yogurt samples was 3.09–4.07 g/10-g-yogurt, lowest for the SDSOM treatment. The release of free fatty acids after simulated gastrointestinal digestions was significantly improved for FDSOMs (94.27%) and SDSOMs (103.29%) when compared to the unencapsulated SO (89.20%). Findings from this study may be significant to manufacturing functional yogurts with polyunsaturated fatty acids.