Effects of maltodextrin concentration and inlet temperature on the physicochemical properties of spray-dried kuini powder
Yu Von Germaine Chng, Lee Sin Chang, Liew Phing Pui
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.