Compositional Changes in the Extra Virgin Olive Oil Used as a Medium for Cheese Preservation

Area of Science:

• Food Science
• Analytical Chemistry
• Food Chemistry

Background:

• Extra virgin olive oil (EVOO) is susceptible to oxidative and hydrolytic degradation.
• Whey cheese, in various forms (semi-hard, hard, soft), is sometimes stored or used with EVOO.

Purpose of the Study:

• To investigate the impact of immersing different types of whey cheese (C1, C2, C3) in EVOO on the oil's quality parameters.
• To assess changes in oxidative and hydrolytic indicators, fatty acid profiles, and phenolic composition of EVOO during storage with cheese.

Main Methods:

• EVOO was stored for two months with immersed semi-hard (C1), hard (C2), and soft (C3) whey cheese.
• Oxidative and hydrolytic parameters (e.g., K232), fatty acid composition, and phenolic content of the EVOO were analyzed.

Main Results:

• EVOO stored with immersed cheese showed accelerated degradation compared to control oil.
• Key indicators like K232, myristic acid, and trans-oleic fatty acid exceeded limits in oils with C1 and C2, suggesting standard tests are inadequate.
• Significant reductions in total phenolic content were observed, with C1 and C2 causing greater decreases (-92.1%, -93.5%) than C3 (-85.0%).
• Fatty acid profile changes were attributed to fat migration from the cheese.

Conclusions:

• The chemical composition of cheese significantly influences the quality and composition of EVOO when used as a storage medium.
• Standard analytical parameters may not accurately reflect the quality and authenticity of EVOO used in conjunction with cheese.
• Cheese components beyond protein, such as moisture and carbohydrates, play a role in altering the EVOO's phenolic profile.