Physical properties of powdered pineapple (Ananas comosus) juice-effect of malt dextrin concentration and atomization speed

Using response surface methodology, whole industrialized pineapple juice with added malt dextrin was spray dried with an air inlet temperature of 190 degreesC and outlet temperature of 90 degreesC. The blower velocity was 25,000 rpm, feed rate 0.18 kg/min and variable atomization speed. The physical properties studied were: apparent and true density, color (a, b and L parameters), moisture content and solubility. The results showed that the linear model used describing the relation of the independent variables was significant for the true density. Nevertheless, the regression for the other responses was not significant, suggesting the need for a quadratic model to consider the interactions with the independent variables. (C) 2003 Elsevier Ltd. All rights reserved.