Effects of maltodextrin concentration and inlet temperature on the physicochemical properties of spray-dried kuini powder

Abstract

Kuini (Mangifera odorata) is known for its intense flavour, attractive colour, rich fibre content and antioxidant properties. However, its short shelf life (bruise within a week) limits the availability of this fruit. Hence, spray drying was proposed to transform this fruit into powder to increase its application. The maltodextrin concentration of 5–20% (w/w) and inlet temperatures of 140–180°C were applied to produce kuini powders. The effect of maltodextrin concentrations at constant inlet temperature (160°C) showed that a higher amount of maltodextrin (20% w/w) produced powder with a low water activity (0.16 ± 0.01 Aw), moisture content (2.16 ± 0.60%) and hygroscopicity (20.45 ± 0.60 g/100g) but the orange colour of the powder turned pale. The kuini powder was further spray dried at different inlet temperatures at constant optimal maltodextrin concentration (20% w/w). The kuini powder that was spray dried at 160°C had the optimal properties: low water activity (0.17 ± 0.01 Aw) and hygroscopicity (22.12 ± 0.09 g/100g) with high water solubility index, WSI (79.90 ± 1.85%) and wettability (279 ± 8 s), indicating the powder can be applied as a food ingredient with high solubility. The optimal spray-drying condition for the production of kuini powder was 20% (w/w) maltodextrin concentration at 160°C inlet temperature to have the highest yield of 43.08 ± 2.77%. Eventhough the reconstituted kuini powder had lower viscosity, colour and β-carotene content than kuini juice, this study showed the feasibility of production of kuini powder using spray drying operation which may broaden its application in the food industry.