Exceptional Nutritional Value of Tunisian "Chemlali Tataouine" Olive Oil Confirmed
Recent research conducted by the Biotechnology Center of Borj Cédria and the Olive Biotechnology Laboratory confirms the exceptional nutritional value of the Tunisian "Chemlali Tataouine" variety, considered one of the best in the world.
According to researcher Imen Oueslati, this oil is particularly rich in vitamin E (tocopherol), with a content exceeding 700 mg/kg, three times more than other Tunisian and international varieties, making it a remarkable natural antioxidant.
Oueslati warned against certain traditional practices still prevalent in the region, particularly in Douirat, where drying olives is used to reduce the "margine". These methods, she explained, degrade the quality of the oil, weaken the concentration of antioxidant compounds, and impact the flavor and health value of an oil she describes as a "treasure of Tataouine".
The laboratory's research also demonstrates the therapeutic richness of other local varieties. The Jerboui and Siali varieties contain phenolic compounds effective against allergies, certain cancers, and joint inflammation. Additionally, the leaves of the El Horr variety in Kairouan are distinguished by active molecules in the fight against certain types of breast cancer. Other local varieties have been found to be beneficial for cardiovascular health, reducing inflammation, and preventing risks related to diabetes and obesity.
The researcher emphasized that this nutritional value can be compromised if production conditions do not strictly respect the quality chain: harvest time, collection methods, transport duration, extraction techniques, and storage conditions.
She recommends avoiding too early or too late harvesting: the olive must be purple, neither green nor black, to guarantee an oil rich in aromas and beneficial compounds.
She also warned against storing oil in plastic bags, used "chekara", or unsuitable containers such as plastic containers or clay jars, which expose the oil to light, heat, and oxygen, accelerating its degradation.
Oueslati called for a review of several cultural practices related to olive oil production and conservation, which are still widespread despite their scientifically proven harmful effects. She also denounced misconceptions, including the belief that frying with olive oil is dangerous.
A series of experiments conducted by her team, including 20 frying cycles, showed that olive oil, thanks to its antioxidants, is the least altered in taste and smell and the least likely to produce toxic aldehydes at high temperatures, making it the best option for cooking without losing nutritional value.
She concluded by emphasizing the need to protect and multiply local Tunisian olive tree varieties, an integral part of the country's agricultural and cultural heritage, to ensure their sustainability and preserve their quality.
For his part, the President-Director General of the National Olive Oil Office, Moez Ben Omar, recalled during the information day organized by the Higher School of Commerce of Tunis at the University of La Manouba for World Olive Day, that the vast majority of olive groves in Tunisia are planted with local varieties, while foreign varieties account for only 8% of the total.
He specified that the Office, through the Olive Tree Multiplication Center of Béjaoua, produces nearly 200,000 local plants each year, reflecting the identity and olive heritage of Tunisia.
