Optimization of hot air drying conditions for production of mango powder with retention of color

Abstract:

What drying temperature best preserves the natural color of mango powder during hot air dehydration? This research aimed to identify the most suitable hot air drying conditions for converting fresh mango slices into powder while keeping color attributes close to those of the fresh fruit. Ripe Nam Dok Mai mangoes were sliced to 3 mm thickness, pre-treated with 0.5 % citric acid solution, and dried at three temperatures (50, 60, and 70 °C) in a tray dryer. Dried slices were ground and sieved through a 60-mesh screen. Color values (L*, a*, b*) were measured with a Hunter colorimeter, and moisture content, water activity, and total carotenoid levels were also recorded. Drying at 50 °C retained the highest lightness (L* = 67.3) and yellowness (b* = 38.4) but required 14 hours to reach the target moisture of 5-7 % (w.b.). At 60 °C, color retention was moderate (L* = 62.8, b* = 34.1) with a shorter drying time of 9 hours. Samples dried at 70 °C showed marked browning (L* = 55.4) and carotenoid loss. On balance, 60 °C offered the best trade-off between acceptable color quality and processing efficiency. The findings can guide small-scale processors seeking to produce shelf-stable mango powder without excessive pigment degradation.