Effects of Osmotic Processes on the Bio-Active and Physico-Chemical Properties of Pumpkin Chips Produced by Convective Drying

In this study, pumpkin slices were dried by osmotic drying assisted convective drying method (60 ºC, 70 ºC) for the production of pumpkin chips. The findings of drying temperatures and pre-treatments were investigated on the drying speed, moisture content, effective diffusion, color, total phenol and flavonoid contents, and total antioxidant activity of the produced pumpkin chips. The drying rate values determined for pumpkin chips were determined to vary between 0.0105-0.0208 g moisture/g drying substance minute. Effective diffusion values were determined to be between 2.29-3.77x10-8 m/s. The chroma, total color change, and browning index values of the produced chips were found to be between 33.62-40.38, 88.64-109.06, and 6.10-31.16. The most appropriate color values were determined for 60 and 70 ºC in control samples. The TP substances have changed between 624.50 µg GAE/g fw – 4297.80 µg GAE/g dw.  The TF has changed between 158.52 mg KE/kg fw – and 362.22 mg KE/kg dw.  The TAA has changed between 1.63 µmol TE/g fw – and 8.61 µmol TE/g dw.  The group that best preserved the bioactive substances of chips was the control group samples dried at 70 ºC. According to the results obtained, while the drying process performed in 70 ºC-hot water dipping pre-treatment is recommended in terms of drying kinetics, the drying process performed for the control group is recommended in terms of quality characteristics.