Microencapsulation by complex coacervation as a tool to protect bioactive compounds and to reduce astringency and strong flavor of vegetable extracts

Abstract

Many plant extracts are rich in phenolic compounds. The cinnamon extract is a rich source of proanthocyanidins, polyphenolic compounds that have several beneficial effects to health. However, this extract presents strong flavor, bitterness, causing a sensation of astringency, and its compounds can suffer degradation. In this context, the aim of this work was to encapsulate the Ceylon cinnamon extract by complex coacervation using gelatin and five polysaccharides (gum arabic, pectin, cashew tree gum, carboxymethylcellulose, and κ-carrageenan) as encapsulating materials and to apply the free and encapsulated extracts in ice creams. The morphology of the particles in different temperatures, pH, salt and sugars concentrations was studied, as well as the stability of phenolic compounds and proanthocyanidins during particles storage. Free extract and encapsulated extracts prepared with gelatin/gum arabic and gelatin/κ-carrageenan pairs were added in ice creams that were evaluated by two-sided paired-comparison test and sensory acceptance. Particles presented resistance when submitted to different stress condition, except pH lower than 2 and temperatures higher than 50 °C. The encapsulation mainly using gelatin/κ-carrageenan and gelatin/cashew tree gum as wall materials promoted greater stability of the total phenolic compounds and proanthocyanidins during storage (until 80% of the initial content). Sensorial analysis results showed that the encapsulation using gelatin/gum arabic and gelatin/κ-carrageenan was able to mask the flavor and the astringency of the extract. These results prove that microencapsulation by complex coacervation is an alternative to increase the stability of the cinnamon extract and to overcome some of the challenges for its application in food.