The ultrasound application does not affect to the thermal properties and chemical composition of virgin olive oils

Highlights

• •

  Virgin olive oils (VOOs) were sonicated (40 kHz) during 60 min.

• •

  Bubbles growth was present in the oils during the ultrasound (US) treatments.

• •

  A slight increase of the temperature was observed during the US treatments.

• •

  In general, no alterations on VOOs quality and composition after sonication.

• •

  No significant changes on oils thermal properties were observed by US treatments.

Abstract

In this work, the effects of high power ultrasound treatment (40 kHz) on virgin olive oil (VOO) for different times (0, 15, 30 min) were studied, in order to verify if extent modifications in their chemical composition and thermal properties. The effects of the different ultrasound treatments on VOOs were determined considering the following parameters: quality index (free acidity, K ₂₃₂ and K ₂₇₀), lipid profile (fatty acids and triglycerides composition) minor components (phenols, tocopherols, pigments and volatiles) and thermal properties (crystallization and melting) by Differential Scanning Calorimetry (DSC).

During the ultrasound treatments, bubbles growth was present in the VOO due to the phenomenon of cavitation and a slight increase of the temperature was observed. In general, the ultrasound treatments did not cause alterations on VOO parameters evaluated (oxidation state, lipid profile, minor components and thermal profiles). However, a slight decrease was observed in some volatile compounds.