Bioactive compounds and oxidative stability of feral olive oils from Tunisian Amazigh Mountains using LC-ESI-QTOF-MS approach for the development of innovative food products

The selection of new olive cultivars with a good oil quality among feral olives may be considered as a way to diversify our olive genetic resources and to select new cultivars for oil production under Tunisian conditions. This study was carried out to determine phenolic and tocopherol compounds, pigments, oxidative stability, triacylglycerol, and fatty acid compositions of unstudied feral olive oils, and a comparison was made with the Chemlali cultivar, the most common Tunisian variety. Results demonstrated that the profiles of feral oils were distinctly different from those of cultivated Chemlali oil. All results indicate that there is a wide variability in the chemical characteristics of the studied oils. Our results showed that F3 feral olive oil was characterized by high mean values of total phenols (1073 mg kg(-1)) and oxidative stability (88.4 h). The cultivar genotype factors might explain variability in phenols (105-1074 mg kg(-1)), tocopherol (324-844 mg kg(-1)), C18:1 (57-78%), oxidative stability (26-105 h), and the profiles of triacylglycerol in investigated extra virgin olive oils (EVOOs). HPLC-ESI-MS analyses showed that F3 olive oil contains appreciable amounts of alcohols (399 mg kg(-1)) and high concentrations of secoiridoid derivatives (SID) (545 mg kg(-1)). Therefore, tocopherol analysis revealed the presence of alpha-, beta-, gamma-, and delta-tocopherols in all the studied olive oils. As for total tocopherols, the amount of each tocopherol varied according to genotype. alpha-tocopherol is the most abundant, whereas beta-, gamma-, and delta-tocopherols are less represented. Besides, the results demonstrated the great influence of total phenols and tocopherols on the stability of virgin olive oil (R-2 = 0.9027, R-2 = 0.901, P < 0.05, respectively). Additionally, the statistical analyses (PCA and HCA) can explain the variability of the oil composition according to the cultivar. The feral olive oils constitute a new edible oil source characterized richer in natural bioactive components.

Automated summary

This study analyzed the chemical characteristics of unstudied feral olive oils and found distinct differences compared to cultivated Chemlali oil. It revealed that feral olive oils are richer in natural bioactive components and could serve as a new source of edible oil.