Date based leather production with microwave, hot air and microwave-hot air combination drying methods

In this study, fruit leather was produced without added sugar with the formulation created using date, pumpkin and apple fruits. Hot air (50 and 75 °C), microwave (200 W and 300 W) and microwave-hot air (200 W+50 °C, 200 W+75 °C, 300 W+50 °C and 300 W+75 ° C). The change in moisture content of fruit pulp samples produced using drying methods over time, drying speed were determined. In addition, some quality parameters (total phenolic substance, antioxidant capacity, color, physical and sensory analysis) of the fruit pulp samples were examined. While increasing drying temperature and microwave power level results in shorter drying time; microwave-hot air combination drying reduced the drying time required compared to both hot air and microwave methods. The drying process of the fruit pulp samples took place in a decreasing period, including the drying applications in which a short warm-up period was generally observed. Among the drying methods used, microwave-hot air combination provided a higher drying rate. The highest antioxidant capacity values of the fruit pulp samples were determined by the microwave (300 W) method, and the lowest value was determined in the fruit pulp sample dried by the hot air (75 °C) method. The highest amount of phenolic substances was determined in 300 W+75 °C (1515.75 ± 20.48) and 300 W (1444.79 ± 13.52) applications, and the lowest value was in hot air (50 and 75 °C). It was observed in fruit pulp samples dried with (p<0.05). When the color values were examined, it was determined that the L* values of the fruit pulp samples dried at 300 W+75 °C had the lowest value compared to other drying parameters, while the a* color value had the highest value. According to the sensory analysis results, when the color, appearance, structure-consistency, bite-tear feature and chewability parameters scored by the panelists were evaluated statistically, no difference was observed in terms of drying methods, and the differences between the groups in the general acceptability parameter were statistically significant (p<0.05). According to the general acceptability results, the highest score from the panelists belonged to the 200 W+50 °C microwave-hot air method.