Sallam, Y., Fahmy, A., Aly, M., Abd El-Sallam, E. (2007). EFFECT OF SPRAY DRYING CONDITIONS ON THE YIELD AND PHYSICOCHEMICAL PROPERTIES OF ROSELLE (Hibiscus sabdariffa L.) POWDER.. Journal of Food and Dairy Sciences, 32(2), 1229-1243. doi: 10.21608/jfds.2007.198702
Y. I. Sallam; A. A. Fahmy; M. H. Aly; E. A. Abd El-Sallam. "EFFECT OF SPRAY DRYING CONDITIONS ON THE YIELD AND PHYSICOCHEMICAL PROPERTIES OF ROSELLE (Hibiscus sabdariffa L.) POWDER.". Journal of Food and Dairy Sciences, 32, 2, 2007, 1229-1243. doi: 10.21608/jfds.2007.198702
Sallam, Y., Fahmy, A., Aly, M., Abd El-Sallam, E. (2007). 'EFFECT OF SPRAY DRYING CONDITIONS ON THE YIELD AND PHYSICOCHEMICAL PROPERTIES OF ROSELLE (Hibiscus sabdariffa L.) POWDER.', Journal of Food and Dairy Sciences, 32(2), pp. 1229-1243. doi: 10.21608/jfds.2007.198702
Sallam, Y., Fahmy, A., Aly, M., Abd El-Sallam, E. EFFECT OF SPRAY DRYING CONDITIONS ON THE YIELD AND PHYSICOCHEMICAL PROPERTIES OF ROSELLE (Hibiscus sabdariffa L.) POWDER.. Journal of Food and Dairy Sciences, 2007; 32(2): 1229-1243. doi: 10.21608/jfds.2007.198702
EFFECT OF SPRAY DRYING CONDITIONS ON THE YIELD AND PHYSICOCHEMICAL PROPERTIES OF ROSELLE (Hibiscus sabdariffa L.) POWDER.
1Food Technology Department, Faculty of Agriculture, Cairo University
2Chemical Engineering Department, Faculty of Engineering, Cairo University
Abstract
Roselle extract was spray dried using a maltodextrin of 5 dextrose equivalent (DE) as a carrier material. The influence of a number of process variables, namely, inlet air temperature (130-190 oC), drying air flow rate (19.39- 22.23 m3/h) and compressed air flow rate (600-800 L/h) on the yield and the physicochemical properties of the spray dried powder were investigated. The physicochemical properties of the product (moisture content, solubility, bulk density, monomeric anthocyanins content and percent polymeric color) were studied. The increase of the inlet air temperature increased the spray dried powder percent polymeric color and decreased its solubility, moisture content and monomeric anthocyanins content. The yield percentage of roselle powder was increased by increasing the inlet air temperature up to a 170 oC, and leveled off for higher temperatures. The increase in drying air flow rate increased the powder yield percentage, moisture content, the percent polymeric color and solubility and decreased its monomeric anthocyanins content, while the increase in compressed air flow rate increased the powder yield percentage and monomeric anthocyanins content and decreased its moisture content and solubility. There was no effect of drying air flow rate and compressed air flow rate on the bulk density.