## 4 Discussion
[PERSON] using LC-MS and found caffe acid at concentrations of 10.12, 0.03, 0.02, and 0.01 umol/g in the extracts obtained with AcOEt from the culture medium of the species _Chaetomium globosum_, _Alternaria compacta_, _Alternaria_ sp., and _Alternaria_ sp., respectively. Again, it is found that the fungal species plays a central role in order to optimize the extraction conditions of phenolic compounds produced by fungi. Caffeic acid is classified as a hydroxycinnamic acid, a phenolic compound of the non-flavonoid type that belongs to the group of phenolic acids. These are characterized by a single phenyl group substituted by a carboxylic group and one or more hydroxyl (OH) groups. Not only does it have antioxidant activity, but also antimicrobial, anti-inflammatory, and anticancer activities, among others. It is present mainly in red fruits, coffee, wine, and vegetables [41]. According to [PERSON] et al. [42], the consumption of foods rich in caffeic acid leads to a protective effect against carcinogenesis by preventing the formation of nitrosamines and nitrosamides. The anticancer action of caffeic acid is mainly associated with its antioxidant and prooxidant capabilities, which are attributed to its chemical structure [42]. Natural antioxidants have a wide application in the food industry. They can be used to slow down the oxidation process of various foods, especially lipid food matrices [43]. In our study, we evaluated the ability of the fungal extract obtained under the best extraction conditions to slow the lipid oxidation of extra-virgin olive oil. The results are promising, considering that the fungal extract did not present statistical differences when compared to the standard antioxidant tocopherol, and maintained a lower peroxide value than the other experiments. This is an important finding as there are very few studies that have evaluated the ability of fungal extracts to retard lipid oxidation. Generally, studies tend to examine fruit extracts, such as that of Correia and Jordao [44], which evaluated the protective effect of extracts from different types of grapes. In this case, using butter, the authors verified that after 14 days at a temperature of 20 \({}^{\circ}\)C, the control sample (butter only) presented a higher level of peroxides (56.6 meq O\({}_{2}\)/kg), while the experiments using the grape extracts, rich in phenolic content, obtained from Touriga Franca grapes, presented a lower value of peroxides (38.1 meq O\({}_{2}\)/kg), indicating a potential protective effect against the lipid oxidation. The Brazilian National Health Surveillance Agency (ANVISA, RDC No. 740/2022) [45] authorizes the use of food additives and technological adjuvants in various food products, and the maximum amount of tocopherol allowed to be used as an antioxidant in olive oil is 200 mg/kg. In this study, we used this concentration of tocopherol (0.2 mg/g) as the positive control to evaluate the lipid oxidation of extra virgin olive oil. The fungal extract obtained under the best extraction conditions was able to protect the olive oil against lipid oxidation without significant difference when compared to tocopherol, which highlights once again the potential of this extract to be used in the food industry as an antioxidant, especially for food products rich in lipids.