Processing Effects on Banana Powder Qualities using Drum Dryer

Abstract

The effects of process parameters using drum dryer (banana maturity or peel color index(PCI), banana puree concentration, drum surface temperature and film thickness) on color andmoisture content of the banana powder were studied. Mathematical models were developed topredict the effective moisture diffusivity coefficient and the browning kinetics of banana duringdrying. The Gros Michel banana with maturity of PCI 5 and PCI 6 were used in this study. Thebanana puree with concentration of 80 and 90 percent were prepared by mixing with potassiummetabisulphite solution and 1 % soy lecithin. The puree was then fed to drum dryer at specificprocess conditions, the process parameters were drum surface temperature (120, 130 and 140 oC)and drum clearances or film thickness (0.15 and 0.30 mm). It was found that the effectivemoisture diffusivity coefficient of banana varied from 1.38x10-9 to 4.11x10-9 m2/s, their activationenergy were 43.18 and 54.56 kJ/mol for banana with PCI 5 and PCI 6, respectively. Thebrowning behavior of banana was found to follow the first order of kinetic reaction and theiractivation energy were 77.63 and 64.63 kJ/mol for banana with PCI 5 and PCI 6, respectively.From statistical analysis, it indicated that banana maturity and drum surface temperature hadsignificant effects on the effective moisture diffusivity coefficient and the browning rate constant.

Keywords : Banana Powder / Drum Dryer / Browning Kinetics / Effective MoistureDiffusivity Coefficient