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Olive oil is a very versatile product. It has distinctive virtues in the fields of health and nutrition. For this reason olive oil quality has attracted attention and become the focus of many studies. Olive oil quality depends on several factors such as ripening, extraction method, soil type, climatic conditions, harvesting time, varieties and storage conditions. Quality assessment of olive oil is linked to an important series of physicochemical parameters including free fatty acid content, peroxide value and sensory evaluation. The main objective of this study is to investigate using statistical analysis, the main factors influencing the quality of Tunisian olive oils. Physicochemical analysis of 89 samples of olive oil produced in the region of the Sahel and central Tunisia. This study demonstrates that the main factors influencing Tunisian olive oil quality are: olive ripening, harvesting methods, olive pre-processing storage, olive washing, leaf removing, mixing, separation systems and crushing time. The data also shows that the commercial qualitative parameters of virgin olive oil such as free fatty acids, peroxide value, specific spectrophotometric absorptions in the UV region and sensorial assessment depend on the cultivar and quality of olives before processing. The application of good olive-growing practices complemented by studies similar to this would improve the quality of olive oil produced in Tunisia. This will contribute to the promotion and value of these oils as a regional product.

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This study aims to investigate the effects of the 2,4-dichlorophenoxyacetic herbicide (2,4-D) on plasma lipids, lipoproteins concentrations, hepatic lipid peroxidation, fatty acid composition and antioxidant enzyme activities in rats. Animals were randomly divided into four groups of 10 each: control group and three 2,4-D-treated groups G1, G2 and G3 were administered 15, 75 and 150 mg/kg/BW/d 2,4-D by gavage for 28 d, respectively. Results showed that 2,4-D caused significant negative changes in the biochemical parameters investigated. The malondialdehyde level was significantly increased in 2,4-D-treated groups. Fatty acid composition of the liver was also significantly changed with 2,4-D exposure. Furthermore, the hepatic antioxidant enzyme activities were significantly affected. Finally, 2,4-D at the studied doses modifies lipidic status, disrupt lipid metabolism and induce hepatic oxidative stress. In conclusion, at higher doses, 2,4-D may play an important role in the development of vascular disease via metabolic disorder of lipoproteins, lipid peroxidation and oxidative stress.

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The present paper reports on the impact of the microbial growth changes, occuring during fifteen days of cv. Chemlali preprocessing storage in different containers representing the common practice during olive processing (plastic bags, reticular bags, and plastic boxes), on olive oil quality. Next, the microorganisms of their microflora (Fungi) were isolated and identified and their effect on olive oil aroma and volatile biogenesis was evaluated by comparing the olive oil volatile profile versus fungal volatile organic compounds. HS‐SPME technique was used for volatile component sampling. Virgin olive oil (VOO) chemical quality indices did not show major variations during storage. Olive oil contained novel volatile compounds that could enhance its flavor, but also contained some off‐flavor compounds which could reduce its organoleptic characteristics and thus its quality. Results show that olive microflora can contribute to the biogenesis of olive oil volatiles and thus some genera could potentially be used to enhance olive oil aroma. Practical applications The present paper try to assess the potential contribution of fungi in the biogenesis of volatiles found in olive oil. The identification of microorganisms capable of producing volatile compounds would have a great impact; the diverse functions of Fungal volatile organic compounds (FVOCs) can be developed for use in potential biotechnological applications (biofuel, biocontrol, etc.) with greater market value. For olive oil industry applications, some fungal volatile organic compounds are useful for the control of postharvest plant disease; someothers should be explored due to their antioxidant properties. Application of some of the microflora members or even application of enzymes that these microorganisms produce and that contribute to volatile biogenesis could have much to offer in olive oil quality.

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