engleski

Combination of ultrasound assisted extraction (UAE) and cyclodextrin encapsulation for the isolation of antioxidants from olive pomace

Although polyphenols from olive pomace, have already been recognized as compounds of high added value, due to wide range of their biological activities, their utilization is still limited, mostly because of the lack of efficient, ecologically and economically acceptable methods of their isolation. In this study, continuous ultrasound assisted extraction, previously optimized in terms of time, temperature and probe diameter, was additionally modified by using β- and ɣ- cyclodextrin (8 g/L) as encapsulation agents for phenolic-type antioxidants from olive pomace. Encapsulation with β- or ɣ-cyclodextrin did not have significant impact on total phenolic content (23.53 -25.53 mg GAE/g DP) or ABTS antiradical efficiency of obtained extracts (21.72-23.08 mg TE/g DP). Also, the statistically significant reduction of tyrosol content in β- or ɣ-CD extracts has been observed (80.6 mg/100g DP, 69.3 mg/100 g DP and 56.1 mg/g DP). On the other hand, the content of hydroxytyrosol and oleuropein was significantly increased in extracts obtained with both investigated encapsulating agents. β- and ɣ-CD that showed comparable effects while maximal yields of oleuropein and hydroxytyrosol were obtained in ɣ-CD extracts (79.9 mg/100g DP and 229.4 mg/100g respectively). Generally, the main advantage of using encapsulation agents in obtaining natural extracts is their impact on stability of plant extracts during drying procedure, increased shelf life and improved organoleptic properties of crude extracts. Therefore additional investigations have to be carried out in order to fully assess the potential of cyclodextrins in the formulation of potent, stable and organoleptically acceptable olive pomace extract.

olive pomace ; antioxidants ; ultrasound essisted extraction

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