* Fats in oil: Oils are primarily composed of triglycerides, which are large molecules made of glycerol and three fatty acids.
* Hydrolysis: When oil goes rancid, it undergoes a process called hydrolysis. This means water molecules break down the triglycerides, separating the fatty acids from the glycerol.
* Free fatty acids: These fatty acids are now free and contribute to the acidity of the oil.
* Acidity: Fatty acids are acidic compounds, meaning they can donate a proton (H+) in a solution. The more free fatty acids in the oil, the more acidic it becomes.
Additionally:
* Oxidation: Rancidity is also caused by oxidation, where oxygen reacts with the fats, leading to the formation of aldehydes and ketones. These compounds can also contribute to the acidity.
* Hydroperoxides: Oxidation produces hydroperoxides, which are unstable and decompose into various compounds, including free fatty acids.
Overall, the breakdown of triglycerides into free fatty acids, along with the formation of other acidic compounds, contributes to the acidic nature of rancid oil.
