Spray-drying microencapsulation of plum peel bioactives using Arabic gum and maltodextrin as coating matrix

Abstract

The goal of the current study is to develop a microencapsulation formulation of plum peel bioactives in Arabic gum and/or maltodextrin through spray-drying. A mixture design of experiments was used with 2 coating materials (Arabic gum and maltodextrin) and 1 process factor (inlet temperature) to find the optimum conditions for maximizing the encapsulation efficiency (EE) in terms of total phenolic content (TPC), encapsulation yield (EY), antioxidant activity and total anthocyanin content (TAC). The systems for the selected 4 responses were modeled satisfactorily (p < 0.0001) with non-significant lack of fit (p > 0.05). The optimum conditions (5% maltodextrin and 5% Arabic gum at 160 °C) to obtain the maximum yields (85% EE, 81.50% EY, 5.78 mg trolox equivalents of antioxidant activity per g dried microcapsule and 0.65 TAC as mg cyaniding-3-glucoside per g dried microcapsule) were tested to confirm the proposed method. The difference between the actual and the predicted values were less than 2%. Moreover, morphological and physicochemical properties of the microparticles were also performed. Release behaviour of the TPC was also investigated based on the in vitro digestion test. TPC release in the gastric fluid was higher than in the intestinal fluid (78.92% versus 69.37%).