Microwave Vacuum Drying of Guava

Microwave vacuum drying was used to dry guavas to a final moisture content of ten percent (wet basis). The effects of microwave power density on the drying of guavas were investigated by applying power densities of 0.5, 1 and 1.9 kW/kg. It was observed that the higher microwave power densities give faster drying time but poorer product quality. Additionally, quality assessments were also conducted to compare quality difference between the microwave vacuum dried and conventionally dried samples that was obtained from the market. It was found that the microwave vacuum dried samples gives better rehydration ratios, appearance and also texture. Meanwhile, the flavour and aroma of the conventionally dried samples were more highly preferred. Lastly, the vitamin C retention for both microwave vacuum dried and conventionally dried guavas were found to be similar