Encapsulation and Degradation Kinetics of Bioactive Compounds from Sweet Potato Peel During Storage

Abstract

Research background: The aim of this work was to evaluate utilization of sweet potato peel as a source of bioactive compounds. The effect of solvents (acetone and acetone/ethanol mixture) on extraction efficiency of total carotenods and phenolics from sweet potato flesh tuber and peel, and antioxidant activity were investigated. SPP extract standed out in terms of antioxidant activity and was choosen for encapsulation by spray and freeze drying techniques. Experimental approach: Encapsulation is an effective method to improve phytochemical stability by entrapping the core material with a coating agent. In this study, spray and freeze-drying techniques were applied for improving the stability of bioactive compounds (carotenoids and phenolics) using whey protein as a coating material. The main advantages of applied techniques over the other encapsulation techniques are simplicity, continuity, effectiveness, availability, and applicability. Results and conclusions: Physicochemical characteristics revealed that spray drying resulted in the formation of lower size particles, better flowing properties, and encapsulation efficiency of carotenoids. The retention of encapsulated and non-encapsulated bioactive compounds was monitoring during storage at daylight and dark conditions. Storage conditions affected the carotenoid retention, whereas daylight exhibited the higher degradation rate for all samples. Phenolic compounds exhibited higher retention for all investigated samples. Degradation kinetic parameters suggest the longer shelf life of spray dried encapsulates and potent method for bioactives stabilization. Novelty and scientific contribution: This study demonstrates that the spray drying technique and utilization of sweet potato peel have big potential in functional additives development, with improved nutritional, color and bioactive properties.