Influence of dual-stage sugar substitution pretreatment on drying kinetics and quality parameters of mango

• The dual-stage ultrasound process was used as pretreatment in mango drying.
• Dried samples subjected to the dual-stage ultrasound pretreatment dried faster.
• Dried pretreated samples had lower color change, phenolic and carotenoid contents.
• Sensory evaluation showed pretreated sample with good acceptance.

The aim of this work was to evaluate the use of the dual-stage (D3S) technique as a pretreatment on mango drying kinetics and on product quality. This pretreatment consisted in two stages, in which high-calorie sugars are partially removed from fruit samples in the first stage and, in the second stage, low-calorie sugar (Stevia-derived) is incorporated to the fruit to maintain its sweetness. The drying process was conducted in a fixed bed dryer at 60 °C and air velocity of 2 m/s. Experimental data were fitted successfully using the two-term exponential model. The dried pretreated samples presented faster drying rates. Evaluation of the final product was performed by means of total phenolic content, total carotenoid content, water activity, texture, color and sensorial test. Samples subjected D3S process had lower phenolic and carotenoid contents, reduced water activity, their texture was softer, and color difference was smaller compared to untreated samples. Sensory evaluation showed pretreated sample with good acceptance.