Effect of process parameters on production of ginger oleoresin powder by spray drying using whey protein isolate as the wall material.

The influence of air inlet temperature at 155, 165 and 175 °C and whey protein isolate (WPI) of 15, 25 and 35% concentration on numerous parameters of ginger oleoresin powder produced by spray drying was examined in this research. Powder recovery increased dramatically from 23.35 to 68.43% and 53.66 to 64.27%, respectively, as WPI concentration increased from 15 to 35% and inlet temperature decreased from 155 to 175 °C. Increases in WPI concentration and inlet temperature enhanced dissolving time from 22.36 to 32.17 s and 19.54 to 24.24 s respectively. Water activity, encapsulation efficiency of ginger oleoresin microcapsules increased from 0.16 to 0.22, 75.28 to 82.43% respectively, while total phenolic content decreased from 27.13 to 19.04 (mg GAE/g) when WPI concentration increased. Lower encapsulation efficiency (78.66%) and higher total phenol content (23.57 mg GAE/g) were reported at higher inlet temperatures (175 °C). The encapsulated oleoresin samples also exhibited smaller-sized particles which were tightly packed at higher inlet temperatures. Micrographs of the powdered sample revealed smooth morphology. [ABSTRACT FROM AUTHOR]