Determination of drying characteristics of mountain strawberry dried with hot air-microwave combination

In this study, fresh and dried mountain strawberry (Arbutus unedo L.) fruits were used. The drying characteristics of mountain strawberries dried by hot air-microwave combination were investigated. The quality characteristics of the dried fruits and the differences in the quality of fresh fruit were determined. The effects on drying rate and drying time of mountain strawberry fruits dried under 15 different conditions in combination with different hot air conditions of 50, 60 and 70°C and microwave powers of 90, 180 and 360 W were determined. The average initial moisture content of mountain strawberry samples used in the study was determined as M0 = 1.795 g water/g dry matter. Mountain strawberry fruits dried in hot air at 50°C reach a moisture content of 0.33 g water/g dry matter in 630 minutes; The time required for mountain strawberry fruits to reach the same moisture content during drying at 50°C, which is a hot air condition, and with 90, 180, 360W microwave combinations of 50°C, was determined as 237, 90, 45 minutes, respectively. Drying kinetics were examined with 5 different models and the best model was determined to be Page and Modified Page. The effects of different drying methods and drying conditions on the inner and outer color of mountain strawberry fruit were examined, and the effects of hot air and microwave on the color parameters on the fruits were examined. The amount of ascorbic acid, was determined by high performance liquid chromatography device. According to the observed results, 360 W and the combinations of this microwave power with hot air caused burns in the samples due to overheating and darkening as a result of changes in colour. For this reason, it was seen that it is more appropriate to use 90 and 180 W microwave power. Vitamin C and drying time were determined as the response and the optimum conditions of the fruit were determined by surface response method with temperature 58°C and microwave power 268W. The results of the study showed that microwave power had a significant effect on drying. It was observed that the microwave power applied together with hot air had an effect on shortening the drying time, increasing the drying rate and effective diffusion coefficient.