Evaluation of Vitamin C Content in Microwave‐Dried Guava (Psidium Guajava L)

This study is carried out to evaluate the effect of different microwave powers on the quality of microwave‐dried guava in term of vitamin C degradation. The effect of microwave heating on the vitamin C content of microwave‐dried guava using three microwave power levels of 300 W, 450 W and 600 W was determined by using High‐Performance Liquid Chromatography (HPLC). All microwave‐dried guava using three different power levels fell in the desired final moisture content range which was 16.01 – 16.05 %. The percentage loss of vitamin C in the microwave‐dried guava was 6 %, 63.8% and 85.93% at 300 W, 450 W and 600 W microwave power levels respectively. The vitamin C content of the microwave‐dried guava decreased with the increase of microwave power level. Microwave‐dried guava using 300 W power level shown the highest vitamin C content with a peak area of 691909 μV while drying using 600 W power level gave the least vitamin C content with a peak area of 103555 μV. Vitamin C is easily destroyed by the excessive heat and water, as well as exposure to air. For retention of vitamin C in dried fruit, it is recommended to apply lower microwave power level in fruit drying. Therefore, the optimum microwave power level for better qualitymicrowave‐dried guava production assessed is 300 W.