Encapsulation of tributyrin with whey protein isolate (WPI) by spray-drying with a three-fluid nozzle

Tributyrin (TB) is a source of butyrate with the record of improving gastrointestinal tract (GI) health. The incorporation of TB in food is challenging because of its bitter taste and the need for a controlled release in the GI tract. Encapsulation of tributyrin with whey protein isolate using spray-drying will expand its application in food matrix. In this study, a novel three-fluid nozzle (3FN) for spray-drying was introduced to produce the microcapsules. The effect of two feed streams into 3FN, the emulsion composition in the inner channel and the concentration of the wall material in the outer channel was investigated. Surface oil, encapsulation efficiency, physical properties of the powders, and the stability of reconstituted emulsion were evaluated. All the properties were also compared with the corresponding samples produced with a two-fluid nozzle (2FN). The results showed that 3FN reduced the surface oil of microcapsules compared to 2FN. No significant difference was observed in surface morphology and internal structure of the powders according to SEM images. However, 3FN sample has a lower level of flocculation and coalescence of droplets when reconstituted and stored indicating the higher stability during the 24 h of refrigerated storage than 2FN samples. The results indicated that 3FN is a novel method to produce microcapsules. The results indicated that 3FN provides a new approach to modify the properties of spray-dried powders with two feeding channels.