Assessment of refractive window drying of physalis (Physalis peruviana L.) puree at different temperatures: drying kinetic prediction and retention of bioactive components

The aim of this study was to assess the refractive window (TM) drying (RW) on retention of bioactive components and drying kinetics of physalis (Physalis peruviana) puree at different temperatures (50, 60, 70, 80 and 90 degrees C). Freeze-drying (FD) was used as control. Drying kinetic was evaluated by mathematical modeling. Antioxidant potential (DPPH/ORAC), total phenolic content (TPC) and total flavonoid content (TFC) were determined using spectrophotometric techniques. The content of tocopherols and fatty acid profile were determined by HPLC and GC, respectively. The Midilli & Kucuk model obtained the best fit for drying kinetics and an activation energy of 29.46 kJ/mol was determined at 60 and 70 degrees C. Samples showed higher antioxidant capacity with better retention of TPC (174.73 +/- 7.00 mg GAE/100 g and 184.20 +/- 12.60 mg GAE/100 g) and TFC (119.68 +/- 4.54 mg QE/100 g and 141.60 +/- 5.47 mg QE/100 g). Similar values of tocopherol contents were found between RW and FD. Linoleic acid is the main polyunsaturated constituent detected. RW showed a great retention of bioactive components, making it an alternative to preserving food.

Automated summary

This study assessed the effect of refractive window drying on bioactive components and drying kinetics of physalis puree at different temperatures. The results showed that refractive window drying had good retention of bioactive components and can be an alternative method for preserving food.