What You Need to Know
The oil layer reduces oxygen diffusion to <0.1 mg O₂ L⁻¹, forming a chemical barrier that slows lipid oxidation and inhibits aerobic microbes. Residual lipase activity hydrolyzes phenolic glycosides such as oleuropein, reducing bitterness while preserving antioxidant phenols like hydroxytyrosol. The process also preserves the olives’ firmness through controlled salt and temperature conditions.
The Science
Primary Reaction
Anaerobic fermentation and enzymatic hydrolysis of phenolic glycosides (oleuropein) by residual lipase activity