Microencapsulation of hop bioactive compounds by spray drying: Role of inlet temperature and wall material

This study explores the effect of spray-drying (SD) inlet temperatures (T_inlet 120 and 150 °C) and wall material on the chemical and physico-chemical properties of microencapsulated hop extracts (MHE). Hop extract was formulated with maltodextrin (MD) and gum Arabic (GA) used in single or in combination with β-cyclodextrin (βCD). MHE were evaluated for physical properties, bitter acids (BA), total polyphenol content (TPC) and encapsulation efficiency (TPC EE), and antioxidant capacity (AOC). Powders produced at T_inlet 150 °C exhibited the highest flowability and generally higher TPC yield. Besides T_inlet, MD enabled the obtaining of MHE with the highest encapsulation efficiency. Other physico-chemical and antioxidant properties differently varied depending on the T_inlet. Overall, the βCD addition positively affected α-acids, and β-acids of MHE obtained at T_inlet 120 °C. ATR-FTIR analysis showed hydrogen bond formation between hop compounds and βCD. Multifactorial ANOVA highlighted that T_inlet, W, and their interaction influenced almost all the chemical and physico-chemical properties of MHE.