Production of a mixed fruit juice powder using mixture analysis and a fuzzy model

The present work aimed to find a mixed fruit juice powder with high antioxidant activity and sensory score. A two-step fuzzy algorithm and fuzzy toolbox were applied to produce acceptable sensory data for the mixture analysis design. The mixture design was then analysed using two responses of sensory and antioxidant activity, and the optimised beverage consisted of red grape (20.4%), mulberry (75.6%), and strawberry (4.0%). As compared to single fruit juices, the selected mixture yielded high content of phenolic compounds with desirable antioxidant activity and sensory score. Spray- and freeze-drying were then compared for the fruit juice powder production from selected mixed juices formulated with 20% maltodextrin (DE = 20). A significant (p < 0.05) difference was observed between the powder yield (82.0% in comparison to 51.7%), free radical scavenging activity (85.6% in comparison to 75.4%), and total phenolic content (2958.8 in comparison to 2791.4 mg GAE/L) of the freeze- and spray-dryer, respectively. Furthermore, the spray-dried powder was much lighter than the freeze-dried powder, with a lower chroma index, redness, and higher hue angle. Overall, freeze-drying was less destructive than spray-drying in the powder production from the mixed juice.