New perspectives on the ozonated high-oleic sunflower oil physico-chemical behaviour.

Area of Science:

• Food Chemistry
• Lipid Oxidation
• Ozonation Technology

Background:

• High-oleic sunflower oil (SFO) possesses inherent antioxidant properties.
• Limited research exists on the physico-chemical characterization of ozonated SFO.
• Understanding ozonation effects on SFO is crucial for potential applications.

Purpose of the Study:

• To characterize ozonated SFO and its water emulsion.
• To evaluate the impact of ozonation on SFO's stability and antioxidant capacity.
• To investigate the role of water in the ozonation process of SFO.

Main Methods:

• Cold-pressed SFO was subjected to ozonation, both neat and as a water-SFO emulsion (1:9 ratio).
• Physico-chemical properties (acid value, peroxide value, rheology) were assessed.
• Structural analysis (NMR, FTIR) and antioxidant activity (free radical neutralization, Fe²⁺ binding, lipid membrane protection) were evaluated.

Main Results:

• Ozonated SFO samples exhibited excellent long-term stability, indicated by stable acid and peroxide values over 6 months.
• Ozonation increased viscosity and flow activation energy, surpassing those of raw SFO.
• NMR and FTIR confirmed high ozonation degrees via Criegee's mechanism, with water accelerating the process.
• Both ozonated SFO types demonstrated potent antioxidant capacities, including free radical scavenging and metal ion chelation.

Conclusions:

• Ozonation significantly enhances the stability and antioxidant properties of high-oleic sunflower oil.
• The presence of water accelerates the ozonation of SFO, offering a potential processing advantage.
• Ozonated SFO shows promise as a functional ingredient, warranting further in-vivo investigation.