Development of Syzygium aromaticum (L.) essential oil encapsulates by ionic gelification and evaluation of antioxidant activity

Abstract

The objective of this work was to develop a product capable of protecting Syzygium aromaticum (clove) essential oil against high volatility. Clove oil (CEO) was encapsulated in alginate by ionic gelation with subsequent freeze-drying. Characterization was carried out by GC/MS, TGA/DSC and antioxidant (DPPH), and total phenol (Folin-Ciocalteau) analysis. Eugenol was the majority (81.5%) and the encapsulation efficiency varied between 14.0%+0.96 (F1: 1.0% alginate) and 9.8%+0.35 (F2: 2.0% alginate) in wet encapsulates, and 23.5%+0.14 (LF1: 1.0% alginate) and 16.9%+0.16 (LF2: 2.0% alginate) in freeze-dried encapsulates. The total phenol content reached 714.8+0.97 EAG g-1 in LF1, with strong inhibition of the DPPH radical (71.4%). Freeze-drying provided a higher percentage of active ingredients per gram of encapsulated and it was possible to identify high thermal stability in LF1 (mass loss: 81.8%; 258.9 °C) compared to wet encapsulates (mass loss: 86.5%; 65.8°C). The use of the lowest concentration of alginate seems to have been favorable. In this way, the accessible technology used allows preserving the content and properties of the CEO, offering a basis for new encapsulated research.