Seven Factors Causing Oxidative Rancidity in Edible Oils

Unrefined oils can undergo oxidative rancidity during storage due to various factors, affecting the quality and safety of edible oils. Consuming severely oxidized oils can harm the digestive system, liver, kidneys, and heart, causing vomiting, diarrhea, and in severe cases, tumors, cancer, or death. What causes oxidative rancidity in oils? 

Seven factors causing oxidative rancidity of edible oils

1. Catalysts:

 Oils contain pro-oxidant substances, including trace metals, especially transition metals, which significantly impact oxidation. These strong catalysts shorten the induction period of oxidation and accelerate the reaction.

2. Temperature: 

Temperature is a crucial factor affecting the rate of chemical reactions. Generally, for every 10°C increase, the reaction rate doubles. Temperature also plays a vital role in the oxidation rate of oils.

3. Oxygen:

The auto-oxidation and polymerization processes involve the reaction of oils with oxygen. The oxygen absorption increases gradually during these processes. Typically, the higher the oxygen concentration, the faster the oxidation. In storage containers, the higher the partial pressure of oxygen, the quicker the oxidation.

4. Moisture: 

Moisture can cause and promote the spoilage of hydrophilic substances (like phospholipids, enzymes, and microorganisms), enhance enzyme activity, and support microbial growth, leading to hydrolytic rancidity and increased peroxide formation.

5. Light and Radiation:

Light, especially ultraviolet light, promotes oil oxidation due to photo-oxidation. It can decompose trace amounts of hydroperoxides in oils, generating free radicals and initiating chain reactions that accelerate oxidation. High-energy radiation can significantly increase the sensitivity to oxidative rancidity, often explained by the induction of free radicals by radiation energy.

HUATAI Oil Machinery reminds you: Refined oils processed with refining equipment can extend storage life and ensure safety. Generally, oils do not spoil within the specified period, but attention should still be paid to the storage environment to prevent spoilage due to environmental factors.