Encapsulation of an astaxanthin-containing lipid extract from shrimp waste by complex coacervation using a novel gelatin–cashew gum complex

Abstract

In the present work, the suitability of cashew gum for forming coacervates with gelatin and encapsulating a lipid extract from shrimp waste was studied. Gelatin and cashew gum formed coacervates at pHs ranging from 4 to 4.5. They were spherical in shape and tended to aggregate and form clusters at pH 4–4.2, whereas they were formless at pH 4.3–4.5. The coacervates were able to encapsulate the lipid extract (astaxanthin encapsulation efficiency 59.9 ± 0.01%), forming multinucleated, polymorphic microcapsules with an average size of 32.7 ± 9.7 μm. An accelerated stability study (43 days/36 ± 1 °C/80% relative humidity) revealed an improvement in astaxanthin stability as a result of encapsulation. The microcapsules, which showed a water solubility of 28.6 ± 4.7%, dispersed well in plain yogurt, selected as a food matrix to evaluate their coloring capacity. The color provided to the product by the encapsulated lipid extract was different in hue to that of the non-encapsulated one, showing higher chromaticity at comparable concentrations. A trained sensory panel confirmed the improvement in coloring capacity achieved through encapsulation, although no differences in odor were found.