Storage stability of the natural colourant from <i>Justicia spicigera</i> microencapsulated in protective colloids blends by spray‐drying

Abstract

Summary Muitle ( Justicia spicigera ), a Mexican native plant, produces a purple aqueous extract (MAE) because of its anthocyanin content. The aim of this work was to microencapsulate MAE by spray‐drying in two different protective colloids blends in a 1:1 weight ratio: gum Arabic‐mesquite gum (GA50‐MD50) and mesquite gum‐maltodextrin DE10 (MG50‐MD50), yielding the microcapsules M GA50‐MD50 and M MG50‐MD50 . The minimum integral entropy of the microcapsules was determined at 20, 35 and 40 °C, and the resulting water activities ( a W ) were 0.555, 0.592, 0.627 for M GA50‐MD50 and 0.581, 0.587, 0.648 for M MG50‐MD50 , respectively. These a W temperature sets were considered as the most adequate conditions for achieving maximum storage stability of the microcapsules. Total anthocyanin content (TAC) and total colour change (Δ E ) suffered considerable degradation at all storage conditions, but that degradation was significantly inhibited by encapsulating MAE in the biopolymers blends especially that made up by MG50‐MD50.