Spouted bed as an efficient processing for probiotic orange juice drying.

This study evaluated the influence of spouted bed drying temperature and maltodextrin dextrose equivalent on the probiotic microbial survival during drying and storage period and on physicochemical properties of fermented probiotic orange juice in powder. Probiotic orange juice was spouted bed dried at 60, 70, 80 and 90°C using maltodextrin with a different dextrose equivalent (10, 20, 30 and 39). After drying, the microbial was higher when lower drying temperatures were applied. During the storage, the highest drying temperatures (80 and 90°C) negatively affected the microorganism survival. On the other hand, at the lowest drying temperature (60°C), the product presented higher Aw, what negatively affected the microbial survival during storage. The temperature of 70°C was the best to preserve the microbial viability during storage. Physicochemical parameters were improved when temperature increased and dextrose equivalent decreased.

Powder lemon juice containing oligosaccharides obtained by dextransucrase acceptor reaction synthesis and dehydrated in sprouted bed.

Oligosaccharides can be synthesized using the sugars present in the fruit juices through the dextransucrase acceptor reaction. In the present work, the effect of reducing sugar and sucrose concentration on oligosaccharide formation in lemon juice was evaluated through response surface methodology. The oligosaccharide formation in lemon juice was favored at high concentrations of sucrose (75 g/L) and reducing sugar (75 g/L). At this synthesis conditions, an oligosaccharide concentration of 94.81 g/L was obtained with a conversion of 63.21% of the initial sugars into the target product. Oligosaccharides with degree of polymerization up to 11 were obtained. The lemon juice was dehydrated in spouted bed using maltodextrin as drying adjuvant. The powder obtained at 60°C with 20 % maltodextrin presented low moisture (2.24 %), low water activity (Aw = 0.18) and the lowest reconstitution time (~46 s). The results showed that lemon juice is suitable for oligosaccharides enzyme synthesis and can be dehydrated in spouted bed.

Hygroscopic behavior and degree of caking of grugru palm (Acrocomia aculeata) powder.

This work aims to investigate the hygroscopic behavior of grugru palm powder through adsorption isotherms and its degree of caking. The powders of grugru palm (T1 - without maltodextrin, T2 - with 8 % of maltodextrin) were obtained by oven drying at 65 °C for 25 h. The experimental data was obtained through static gravimetric method at temperatures of 25, 30, 35 and 40 °C with different saturated salt solutions. The models of GAB, BET, Henderson, and Oswin were fitted to experimental data. The values of hygroscopicity were 6.39 and 5.17 % and degrees of caking were 3.11 and 0.03 % for T1 and T2, respectively. The adsorption isotherms from mathematical models can be classified as Type III. The GAB and Oswin models were the best representing the behavior of the powder isotherms, T1 and T2, respectively. The grugru palm powder proved to be non-hygroscopic and non-agglomerating. The T2 with 8 % of maltodextrin presented the lowest hygroscopicity.