Stability of the physical properties, bioactive compounds and antioxidant capacity of spray-dried grapefruit powder

Spray-drying may be an interesting alternative means of offering consumers high quality, stable, and easy-tohandle fruit. The stability of grapefruit powder formulated with gum Arabic, maltodextrin and whey protein isolate was studied. The changes during powder storage at 20 degrees C of the vitamin C (VC), total phenolics (TP), lycopene (Lp), antioxidant activity (AOA), color and mechanical properties were studied at different relative humidities (RH), from 0 to 56% for up to 9 month, either exposed to light or in darkness. Results showed that TP were the most stable compounds and Lp the most unstable. The properties studied with grapefruit powder were relatively stable when stored at 20 degrees C, in darkness or light, at RH <= 23.1% and for no more than 6 months. With these conditions, losses of 32, 3, 23-68 and 90% were observed for TP, VC, AOA and Lp, respectively, and the powder maintained its flowability and color.