Characterization and singlet oxygen quenching capacity of spray-dried microcapsules of edible biopolymers containing antioxidant molecules

A. FERREIRA DE FARIA; R.A. MIGNONE; M. A. MONTENEGRO; A. Z. MERCADANTE; C. D. BORSARELLI

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

American Chemical Society

Lugar: New York; Año: 2010 vol. 58 p. 8004 - 8011

0021-8561

Microcapsules of gum arabic (GA) or maltodextrin 20DE (MD) containing antioxidant (AOx) molecules, such as carotenoids and tocopherol derivatives, were prepared by the spray-drying technique. The properties of these microcapsules were evaluated by several techniques, such as dynamic light scattering (DLS), scanning electronic microscopy (SEM), and steady-state and time-resolved fluorescence spectroscopy of microencapsulated pyrene (Py). The quenching of photochemically generated singlet molecular oxygen (1O2) by the AOx in homogeneous solvent as well as in microcapsule solutions was evaluated using time-resolved phosphorescence detection (TRPD). The quenching rate constant of the process, e.g. kQAOx, was strongly dependent on the type of AOx molecule. These results are explained by compartmentalization effects of the AOx molecules in the core of the microcapsules and the accessibility of 1O2. The contribution of the biopolymer as quencher of 1O2 was also investigated. The present results can be applied to the design of edible antioxidants within the food and cosmetic industries.