**4. Characteristics of antioxidants**

The main characteristic of a compound or antioxidant system is the prevention or detection of a chain of oxidative propagation, by stabilizing the generated radical, thus helping to reduce oxidative damage in the human body [21]. Gordon [22] provided a classification of antioxidants, mentioning that characteristic. There are two main types of antioxidants, the primary (breaking the chain reaction, free radical scavengers) and the secondary or preventive. The secondary antioxidant mechanisms may include the deactivation of metals, inhibition of lipid hydroperoxides by interrupting the production of undesirable volatiles, the regeneration of primary antioxidants, and the elimination of singlet oxygen. Therefore, antioxidants can be defined as "those substances that, in low quantities, act by preventing or greatly retarding the oxidation of easily oxidizable materials such as fats" [23].
