It has been reported that at least 35% maltodextrin was needed for the drying of various fruit juices, including apricot, blackcurrant and raspberry. For the immature acerola pice, at least 50% maltodextrin was needed (Fang and Bhandari 2012). More than 60% of maltodextrin was needed for spray drying of orange juice (Jayasundera et al. 2009; Fang and Bhandari 2012).
Table 4 indicates a significant increased of powder yield from 20.87 ± 5.41 to 57.42 ± 8.25% as the concentration of maltodextrin increased from 10 to 30% (w/v). The yield became constant between 30 and 40% (w/v) maltodextrin addition but was significantly (P< 0.05) decreased when 50% (w/v) maltodextrin was added. According to Taufik (2009), the limit when more drying agent was added but produced no more increase of powder yield was called the optimum dosage. There would not be improvement on yield but increases the cost if the concentration of maltodextrin was further increased. Moreover, too much maltodextrin would increase the TS content and led to high viscosity in the feed solution, which would negatively affect the drying performance (Tonon et al. 2008; Garcia-Cruz etal. 2013). Thus, in this study, spray drying with 30% (w/v) maltodextrin was the optimum dosage and was chosen as the best parameter.