Carotenoid stability in high total solid spray dried emulsions with gum Arabic layered interface and trehalose–WPI composites as wall materials

Abstract The present study investigated the ability of spray dried single layer (SL) and layer-by-layer (LBL) high total solid emulsions with carbohydrate (trehalose) and non-carbohydrate (WPI) solids to stabilize carotenoids upon storage at 35 °C, 50 °C, and 65 °C. Carotenoid loss followed first order loss kinetics, and increased with increasing storage temperature. Rapid initial first order loss followed by a second, less rapid first order loss was observed. Storage of the systems above the T g reduced carotenoid loss in the initial first order loss. The loss of carotenoids in LBL system was more temperature dependent initially but SL system was more temperature dependent in the second first order loss step. LBL system showed slower loss rate of carotenoids in the initial first order loss step and at 65 °C in the second step. Carotenoid retention was significantly higher in LBL system upon storage at 65 °C. Industrial relevance Although layer-by-layer (LBL) technique has been known to produce emulsions with better stability towards environmental stresses, few have reported the application of LBL technique using systems with high total solids. The application of LBL technique on emulsion with high total solids and subsequent spray-drying of the emulsion in this manuscript will provide useful information to the food and pharmaceutical industries. The possibility to spray-dry such systems with high total solids producing high quality powders would be feasible to the industry as it greatly reduces production cost. The present study also reports on the carotenoid loss kinetics of dehydrated concentrated systems with carbohydrate and non-carbohydrate mixtures as wall materials and compares the ability of single layer (SL) and LBL systems in preventing the loss of the encapsulated carotenoids.