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Microencapsulation by spray drying from an extract of the calyces of hibiscus sabdariffa l.

Abstract:

The objective of the research was to define the best conditions for ultrasound-assisted extraction of H. sabdariffa L. calyces, and to obtain microencapsulated powders, by spray drying. The extracts were analyzed, considering as variables: extracting solvent (water and water/ethanol) and the temperature /extraction time ratio (25 ºC/ 60 min and 60 ºC/30 min). Inlet air temperature (150 ºC; 190 ºC) and the mixture of gum arabic (G) and maltodextrin (MD) as encapsulating agents (G40/MD60; G60/MD40) were the variables studied. The parameters used for the analysis were: yield, pH, ºBx, chemical composition (phenols and total anthocyanins, HPLC-MS), and antioxidant capacity (DPPH). The best polyphenols extraction conditions were water:ethanol (80:20), at 60 ºC for 30 min. The presence of phenolic acids, flavonol glycosides, and anthocyanins (delphinidin-3-sambubioside and cyanidin-3-sambubioside) were identified as the signals of highest intensity. Inlet air temperature at 150 ºC and G60/MD40 allowed the highest total phenols and anthocyanins content. However, the antioxidant capacity was better at 150 ºC and G40/MD60. The microparticle obtained could be used as an ingbkp_redient for the preparation of phytopharmaceuticals or functional foods, considering their easy handling, and antioxidant capacity.