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Abstract
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Infrared assisted vacuum drying technology is a newly emergedstrategy, which found its place in the food drying industry. Therefore, in this research,the effectiveness of near infrared (NIR) and medium infrared (MIR) radiation was experimentally investigated on drying kinetics and some quality properties of quince slices under vacuum condition. Experimentswereconducted at dryingtemperatures of 50, 60 and 70°C and absolute pressures of 20, 40 and 60 kPa for NIR and MIR radiations. Drying processinMIR assisted vacuum drying domainlasted about 3 to 28 min lower than NIR one, indicating improved drying process under MIR condition. Effective moisture diffusivity( ) for NIR domain wasobtained in the range of 0.17×10-9 to 0.46×10-9m2/s while it was between 0.18×10-9 to 0.46×10-9 m2/s under MIR condition.Minimum specific energy consumption ( ) for NIR and MIRradiation was estimated 0.55 and 0.34 kWh,respectively. Total color difference and sample shrinkage under NIRradiation were calculated within the range of 5.5 to 25.4% and 40.4 to 64.5%, respectively, which were significantly lower the ranges of MIR. Minimum total color change (5.5%) and shrinkage (40.4%) of quince samples werecalculatedunder NIR conditionwhile, the minimum values for MIR domain were 12.1 and 50%, respectively.
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