Effects Of Spray -Drying Conditions On Physical And Functional Properties Of Instant Purple Sweet Potato (Ipomoea Batatas L.) Powder

Abstract

Purple sweet potato powder can enhance food products by color, flavor, and nutrients. Microencapsulation is used for protection, stabilization, and the slow release of the core material. This study aimed to investigate the influences of spray-drying conditions, such as inlet air temperature (110oC, 130oC, 150oC), concentrations of carrier agents (10%, 15%, 20%), and the ratios of maltodextrin and gelatin as wall materials in total anthocyanin contents, antioxidant activity, solubility, micro-structure and encapsulated efficiency of PSPP. The ratio and concentration of carrier agents were significantly affected by the functional and physical properties of PSPP (p < 0.05). The highest TAC and TAA (22.1 mg/100 g db and 6.43%, respectively) were obtained when the sample prepared at ratio 7:3 with 10% concentration. The encapsulated efficiency was also with 58.5% at ratio 7:3 with 10% concentration. The solubility of PSPP at 7:3 with 10% concentration was 9.09% when decreasing the amount of gelatin added. Meanwhile, the comparison of solubility for different concentrations was not affected (p < 0.05). To save money, the concentration at 10% should be chosen. The study on temperature had no significant influences on TAC and solubility of PSPP. However, the determination of TAA and EE had significant differences when changing temperature. Although TAC was not affected, it could be clearly seen that the highest value was 22.57 mg/100g db at 130oC compared at other temperatures. At 130oC, the powder sample had the highest values of TAA (10.67%) and EE (61.27%).