Influence of shell material on vitamin C content, total phenolic compounds, sorption isotherms and particle size of spray-dried camu-camu juice.

Introduction. Camu-camu is a native Amazonian fruit mainly known for its high vitamin C content. Its composition confers high antioxidant capacity on this fruit and makes it a potential source of antioxidant products. The use of spray-drying with the aid of a carrier agent is a technique that has been applied for the preservation of important components of foods and drugs. The objective of our work was to evaluate the influence of those agents used as shell material on the vitamin content and total phenolic compounds of camu-camu powder juice obtained by spray-drying. Materials and methods. A commercial frozen camu-camu pulp was the raw material; maltodextrin and gum arabic were the selected carrier agents. Processes were performed in a mini-spray-dryer with inlet and outlet air temperatures of 180 °C and 85 °C, respectively, and a drying air flow rate of 700 L·h–1. Laser diffraction was used to determine the particle size distribution of the samples, and sorption isotherms of spray-dried camu-camu were measured using a static gravimetric method. Total phenolic compounds and vitamin C were determined in the raw pulp and in the powders obtained. Results. When using gum arabic and maltodextrin as the carrier agents, the moisture results obtained for the spray-dried camu-camu powders were 2.8% and 3.2%, respectively; the process yield was 84% and 72%, respectively. The spray-dried powder produced using gum arabic presented higher contents of vitamin C [(15,363 ± 226) mg·100 g–1] and phenolic compounds [(6,654 ± 596) mg GAE·100 g–1] than the powder obtained with maltodextrin, respectively (11,258 ± 298) mg·100 g–1 and (5,912 ± 582) mg GAE·100 g–1. Conclusions. The concentration factors for the vitamin C and phenolic compounds in camu-camu powder reveal the effectiveness of spray-drying to preserve the antioxidant capacity of this fruit. Gum arabic was a more effective barrier than maltodextrin for bioactive compound retention. [ABSTRACT FROM AUTHOR]