In this study, Opuntia ficus‐indica mucilage was evaluated as a protecting agent of anthocyanins from Solanum melongena L. by spray drying. The performance of mucilage as a protectant was evaluated using the ratio of the percent of Radical Scavenger Activity (RSA) to the concentration of anthocyanin [C]. The results showed that, in presence of mucilage, after 4 months the %RSA/C was preserved in 73% of wet samples and in 64% of spray dried samples, compared to wet samples without mucilage, where %RSA/C preserved was 30%. Additionally, it was found that acidified mucilage (0.4%) could be used as a viable extracting and encapsulating agent, thereby avoiding the use of organic solvents and the generation of associated residues. Also, the acidification modified the rheological behavior of mucilage from non‐Newtonian to Newtonian, improving the spray drying process and preserving the %RSA/[CA] in 96% of samples after drying. Microcapsules observed by SEM showed a worm‐like morphology.
Acidified mucilage as an ecological extraction medium can be widely recommended due to its dual effect of preserving the antioxidant activity of the anthocyanins present in eggplant peel, and for avoiding organic solvents such as acetone, methanol and ethanol that are traditionally used in this type of extraction, but represent a source of pollutants in processing. Moreover, the viability of mucilage as an agent(material) to encapsulate and keep the properties of anthocyanins by spray drying without other encapsulating agents, opens the possibility of a new alternative in the conservation of food industry colorants. Additionally, the use of acidified mucilage is expected to reduce the number of stages in processing, the processing time, as well as the raw material involved, thereby providing additional economic benefits.