Physicochemical properties and bioactive compounds content in encapsulated freeze-dried powders obtained from blueberry, elderberry, blackcurrant and maqui berry

BACKGROUND: Berry fruits stand out for their high contents of anthocyanins responsible for their red-purple color. The region of Patagonia, Argentina, is a significant cultivar region of these fruits. Due to berries' very short shelf-life, it is interesting the development of dehydrated products that can be stored at room temperature and still be a source of bioactive components and natural colorants. OBJECTIVE: The objective of this work was to evaluate the effect of freeze-drying process and storage at 38 degrees C on the levels of bioactive compounds and color, in lyophilized products based on blueberry, blackcurrant, elderberry and maqui berry pulps from the E1 Bolson area, Rio Negro, Argentina. METHODS: Fruit pulps with addition of encapsulating agents (Maltodextrin/Arabic gum) were freeze-dried and evaluated for the content of monomeric anthocyanins, total polyphenols, antioxidant capacity, color (CIELab parameters) and physical characteristics. RESULTS: The obtained freeze-dried powders showed high levels of retention of bioactive compounds, yielding between 68.2 and 99.6% of retention of polyphenols and anthocyanins depending on the fruit. Color parameters were also stable after freeze-drying and during 60 days of storage at 38 degrees C. CONCLUSIONS: The obtained stable powder ingredients based on berries from Patagonia can be used as a source of bioactive compounds and pigments.