Freeze Dried Acerola (Malpighia emarginata) Pulp and Pomace: Physicochemical Attributes, Phytochemical Content and Stability during Storage

Abstract

In this study, acerola pulp and acerola pomace were freeze dried with and without gum Arabic (GA) and analyzed in regard to their physicochemical attributes, bioactive content, and phytochemical stability (total phenolic content, ascorbic acid, total monomeric anthocyanins and antioxidant activity), during storage at 4 oC and 25 oC. The freeze dried products were highly porous and had low water activity (0.273 to 0.300). Freeze dried acerola pulp with GA were the most soluble samples (64.1% to 73.7 %). The addition of GA to freeze dried acerola pomace increased samples hygroscopicity from 4.5% to 11.1%. High ascorbic acid retention in freeze dried acerola pulp was observed for all samples (65.2 % at 25 °C and 88.9% at 4 °C). It was observed that freeze dried acerola pomace showed increased antioxidant activity during storage (101.9% at 4 °C and 135.9% at 25 °C). Our results demonstrate the potential of freeze dried acerola pulp and pomace as novel food ingredients with concentrated phytochemical content and desirable physicochemical attributes.