Encapsulated cactus pigments as food colorants. Stability and uses in a food model system.

OTÁLORA, M.C.; CARRIAZO, J.G.; OSORIO, C.; NAZARENO M.A.

Coquimbo

Congreso; IX International Congress on Cactus Pear and Cochineal; 2017

International Society for Horticultural Science

Opuntia fruits are good sources of betacyanins and betaxanthins which can be used as natural red-purple and orange-yellow food colorants, respectively. Pigment encapsulation has been assayed to improve its stability. In this work the encapsulated betacyanins (EBC) and betaxanthins (EBX) were prepared by spray drying (SD) and ionic gelation (IG), using a maltodextrin combined with cladodes mucilage and a calcium alginate matrix, respectively. The encapsulated pigments were characterized; besides, the storage stability and functional properties of EBC and EBX were compared, being the latter more stable than the red-purple pigments. Degradation reaction of encapsulated betalains followed pseudo-first order for SD kinetic and first-order for IG one. Encapsulated pigments (EBC and EBX) were successfully applied in two different food model systems: yogurt (SD microcapsules) and jelly gum (IG capsules). The pH value of yogurt (pH 4.3) and low moisture content of jelly gum (aw 0.40) were important parameters in the microbiological stability during the storage. Color is the first criterion that is used in the acceptance or rejection of a product by consumers, and it is an important attribute of quality for the food industry. Model food systems presented a vivid red-purple and orange color after one month of storage under refrigeration (4°C). Color changes in these products were evaluated between the samples at zero time and after 30 days of storage, showing the stability of the betalains in the food model system. The encapsulated pigments those prepared by SD and by IG are both promising functional additives which can be used as natural colorants for healthy foods taking into account the well reported medicinal properties of betalains.