Encapsulation of pomegranate peel extract in sucrose matrix by co-crystallization

Many researchers have turned their attention to the polyphenolic content of pomegranate peels. However, polyphenols are unstable compounds and this is the biggest deterrent to their use in the food industry. The aim of this study was the effective encapsulation of pomegranate peel phenolic extract in the matrix of sucrose by co-crystallization utilizing three different experimental designs, the two level factorial design (F), the Central Composite design (CCP), and the Box-Behnken design (ΒΒ), from which the one with the higher predictive ability was selected. The examined parameters were the temperature (125–140 °C) at which the extract is incorporated into the sucrose matrix, the extract soluble solids concentration extract (30–60 °Brix), as well as the dry extract to sucrose ratio (0.1–0.7 g/g). The formed powders were analyzed for their physicochemical properties (moisture content, hygroscopicity, solubility, bulk density, color, antioxidant activity). Both the individual optimum conditions for maximizing efficiency and the composite optimum conditions for simultaneously maximizing efficiency and minimizing moisture content across all three different designs of experiments were determined. Of the studied designs, the CCP was the one with the better predictive ability as it presented the smallest deviations between experimental and predicted efficiency values in both optimum and randomized experiments.