Effect of variables on the pineapple powder production using microwave spray dryer

Abstract

The aim of this research is to produce pineapple powder with high qualities by using microwave rig assisted spray drying (MWSD). In previous research used (MWSD) operated at atmospheric pressure to obtain pineapple powder with high inlet air temperatures. All know the effect of high temperature on the foods product especially fruits, it make thermal degradation of powder product, so the final product lose some characteristics. In this study, the drying process carried out with low inlet air temperatures. The experiments were conducted keeping constant the nozzle size, feed flow rate and maltodextrin concentration (DE12): 1mm, 25 ml/min and 25% w/w respectively. Drying was carried out by using 1000 Watt microwave power intensity and with the different inlet air temperatures (40-100 ºC). Also, drying was conducted using 80°C inlet air temperature and with the different microwave power intensities (700-1600 Watt). The product powder was analyzed for moisture content, bulk density and solubility. In two cases, moisture content and bulk density are inversely proportional to the inlet air temperature and microwave power intensity, whereas solubility proportional to the inlet air temperature and microwave power intensity. The best result when inlet air temperature 80°C and microwave power intensity 1000Watt, will produce pineapple powder with 3.91% moisture content, 0.59g/ml bulk density and 33 sec powder solubility. The results showed that the data were adequately fitted into the second order polynomial model.