Effects of pre-drying methods on physicochemical, textural and color quality attributes of explosive puffed dried mandarin snacks

The effect of the pre-drying processes on the physical, chemical, microstructural, color, textural and sensory properties of mandarin chips was studied. The aim of the study is to investigate the effects of different pre-drying methods (microwave drying (MD), hot air drying (HAD), freeze-drying (FD), osmotic dehydration (OD) and microwave combined with hot air drying (HAD + MD) on mandarin chips dried with the explosive puffing drying (EPD) method. Pre-dried mandarins until the moisture content of 70% (wb) were dried at 25 kPa, 60 degrees C for 180 min by EPD. The hybrid method HAD + MD + EPD was shown to be the most effective method for decreasing the moisture content and water activity (aw). It was concluded that the crust structure created during the pre-drying process affected the final product's bulk density and volumetric expansion (VE) characteristics. Therefore, the HAD + MD + EPD combination reduced porosity in mandarin snacks, resulting in lower hardness and increased crispness. Mandarin snacks produced with the FD + EPD method had the highest ascorbic acid content (297.93 +/- 1.92 mg/100 gDM), total phenolic content (181.82 +/- 1.05 mgGAE/100 gDM), and antioxidant activity (220.18 +/- 0.46 TEAC/100 gDM), whereas samples produce with the HAD + MD + EPD method had the highest total carotenoid content and, when the sensory properties were evaluated, the highest crispness and lowest hardness value. In today's world, where healthy snack intake is becoming more common, our study has shown that the HAD + MD + EPD method is an innovative and effective drying method for developing mandarin chips as a healthy snack food while protecting its functional and textural characteristics.