Characterization of ozonated vegetable oils by spectroscopic and chromatographic methods

Area of Science:

• Food Chemistry
• Organic Chemistry
• Oxidation Chemistry

Background:

• Ozonation is a powerful oxidation technique.
• Understanding its impact on edible oils and fatty acids is crucial for food processing and stability.
• Olive oil and soybean oil are common dietary fats with varying degrees of unsaturation.

Purpose of the Study:

• To investigate the effects of ozonation on olive oil, soybean oil, and key fatty acids (oleic, linoleic, linolenic).
• To analyze the changes in chemical structure and physical properties of oils after ozonation.
• To identify reaction products and elucidate the ozonation mechanism.

Main Methods:

• Ozonation of oils and fatty acids with varying reaction times.
• Analysis using Nuclear Magnetic Resonance (1H, 13C NMR).
• Determination of peroxide value, acid value, viscosity, and molar mass.

Main Results:

• Ozonation decreased unsaturation in fatty chains with increased ozonation time.
• Formation of ozonides was observed, consistent with the Criegee mechanism.
• Peroxide and acid values increased, particularly in soybean oil.
• Higher and lower molar mass species (oligomeric and cross-ozonides) were detected after prolonged ozonation.

Conclusions:

• Ozonation effectively reduces fatty acid unsaturation in oils.
• The Criegee mechanism explains the formation of ozonides and subsequent products.
• Ozonation significantly alters the chemical and physical properties of edible oils, with implications for shelf-life and potential applications.