What is the Difference Between Hydrolytic and Oxidative Rancidity?

The main difference between hydrolytic and oxidative rancidity lies in the processes that cause them. Rancidity is a chemical process that involves complete or incomplete oxidation or hydrolysis, resulting in an unpleasant taste and odor in food.

Hydrolytic rancidity occurs when triglycerides are hydrolyzed, liberating one or more volatile fatty acids. This reaction typically requires a catalyst, such as a lipase, or acidic or alkaline conditions, and results in the formation of free fatty acids and glycerol. Factors that can influence hydrolytic rancidity include heat, ultraviolet light, heavy metals, and oxygen.

Oxidative rancidity, on the other hand, is associated with the degradation of fats by oxygen in the air. In this process, the unsaturated fatty acid fragments of glycerides are oxidized at their double bonds, leading to the formation of aldehydes, ketones, and acids. Autoxidation, a spontaneous type of reaction, is responsible for oxidative rancidity in food products.

To prevent or delay the development of rancidity, various methods can be employed:

• For hydrolytic rancidity: storing food in a cool, dark place with little exposure to moisture or enzymes.
• For oxidative rancidity: using light-proof packaging, creating an oxygen-free atmosphere around the food, and adding antioxidants such as ascorbic acid and tocopherols.

Comparative Table: Hydrolytic vs Oxidative Rancidity

Here is a table comparing the differences between hydrolytic and oxidative rancidity:

In summary, hydrolytic rancidity is caused by the action of water and typically requires the presence of enzymes or moisture, while oxidative rancidity is caused by the action of oxygen on unsaturated fats. Both types of rancidity can lead to undesirable odors and flavors in food.