Microencapsulation of pomegranate (Punica granatum L.) seed oil by complex coacervation: Stability and application in an instant caffè latte beverage

Abstract

Pomegranate seed oil (PSO) is rich in highly oxidizable bioactive conjugated linolenic acids (cLnA), limiting food applications. This study aimed to investigate the oxidative stability (room temperature for 90 days; 60 °C, for 10 days, vacuum-sealed or not), physical and morphological properties of PSO microparticles produced by complex coacervation (CC). An instant caffè latte beverage was formulated with PSO microparticles (30%) as a proof-of-application vehicle for the microparticles and physical properties were evaluated. CC was compared with spray drying. Although non-coacervated microparticles showed superior oxidative stability, coacervated microparticles were overall stable for 60 days and cLnA retention reduced 42% after γ-tocopherol exhaustion. Coacervated microparticles' structure was collapsed after 90 days. Storage under vacuum increased the oxidative stability at 60 °C. Microparticles showed high solubility and thermal stability, addition to the product promoted negligible changes in physical properties. This study brings new insights regarding cLnA stability and PSO application in food.

Keywords: Conjugated linolenic acid isomers; Gum Arabic; SPME-GC–MS; Tocopherols; Volatile compounds; Whey protein; catalpic acid (PubChem CID: 5385589); punicic acid (PubChem CID: 5281126); α-eleostearic acid (PubChem CID: 5281115); β-eleostearic acid (PubChem CID: 5282820); γ-tocopherol (PubChem CID: 92729)..