Apricot is one of the fruits dried by using different methods, such as sun, convective or microwave drying. The effects of drying methods on the components of this fruit differ depending upon the temperature or time parameters. In this research, the impacts of convective, microwave and microwave-convective drying techniques on color, β-carotene, minerals and antioxidant activity of apricots were investigated. The color values (L*, b*, ΔE ab, h° and C* ab ) of dried fruit were decreased, while the a* values increased. Compared with a fresh sample, the dried apricots showed a 1.4-3.9-fold proportional increase in β-carotene based on the increment of dry matter. The samples dried at high temperature and microwave levels, at 75 °C+90 watt and 75 °C+160 watt, showed lower antioxidant activity. Df the different drying treatments, the microwave-convective method (50 °C+160 watt) obtained a higher β-carotene content while maintaining antioxidant activity with a short drying time.Keywords: apricot; drying; color; β-carotene; antioxidant activity.Practical Application: This paper presents different drying methods of apricots in addition to optimization of the power level and temperature conditions. These methods make it possible to select the best way to provide high quality and nutritional dried apricots.

Sliced kumquats were dried by using three different drying methods, microwave (375 W), hot air (70 and 80 °C), and vacuum (70 and 80 °C with 100 and 300 mbar) to determine drying characteristics, antioxidant capacity and total phenolic content and color. All color parameters (L, a, b, C ab , ΔE and h°) changed depending on the drying methods. Page and Modified Page models are the best fitted drying methods with the highest value of R 2 (0.9994) and the lowest values of RMSE (0.000635-0.000735) and χ 2 (0.000010-0.000013) compared to other models. Effective moisture diffusivity values for dried kumquats ranged from 1.54 × 10-8 to 8.24 × 10-8 in vacuum drying at 70 °C-300 mbar and microwave drying at 375 W, respectively. On comparison to the fresh sample, the dried samples showed an increase in both total phenolic content and antioxidant capacity. The total phenolic content (3095.71 ± 101.41 mg GA/100g d.w) and antioxidant activity (10.51 ± 0.19 µmol TE/g d.w) with DPPH assay showed the highest levels for the vacuum drying at 70 °C-100 mbar method. Microwave dried samples had the highest antioxidant activity with CUPRAC assay as (17.58 ± 0.63 µmol TE/g d.w.). This study indicated that microwave drying and vacuum drying at 70 °C-100 mbar were able to yield high-quality kumquat slices.

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