Encapsulation of carrot waste extract by freeze and spray drying techniques: An optimization study

Abstract

Carotenoids were recovered from carrot processing waste using sunflower oil. Simplex centroid mixture design was applied for the optimization of wall material formulations (whey protein/maltodextrin/inulin) for the encapsulation of carrot waste extract by freeze drying (FD) and spray drying (SD). The optimal wall materials were pure whey protein, and 71 g/100 g whey protein - 29 g/100 g inulin mixture, respectively, showing total carotenoids of 1.31 and 0.87 mg β-carotene/100 g, encapsulation efficiencies of 63.69 g/100 g and 53.78 g/100 g, and β-carotene bleaching antioxidant capacities of 70.06 and 41.23 μmol TE/100 g. The freeze dried encapsulate showed the best hygroscopicity, oxidative stability and colour properties, while the spray dried encapsulate had the lowest water activity, moisture content and particle size. The morphological properties of the optimal encapsulates were assessed. The techniques and the formulations tested showed a big potential for the preparation of functional food with improved nutritional, colour and bioactive properties.