Incidence of dairy wastewater on morphological and physiological comportment of Chemlali and Chetoui olive

In the present study the analysis of the physico-chemical parameters of the collected TWW shows the BOD, COD, COT, Cl-, NO3, NO2, suspended matter, organic matter, turbidity and conductivity were in accordance with the required Tunisian legislations. In the same occurrence, the ICP-MS and the UPLC-MS/MS analysis show that TWW were devoid of different toxic metals and antibiotics, respectively. We opted to reuse of the TWW in the irrigation of young olive trees of two varieties: Olea europaea L. cv. Chetoui and Olea europaea L. cv. Chemlali which receiving 1 L/week of TWW during five months. Results show that dry roots weight and the content of chlorophyll a in 'Chetoui' variety increased significantly (p < 0.05) when compared to the control group. On the same way, significantly increase of leaf area, dry roots and leaves weights was observed in 'Chemlali' variety treated with TWW. Keywords: Dairy wastewater, Reuse wastewater, Olea europaea L., ICP-MS, UPLC-MS/M

Effect of leaf-to-fruit ratio and girdling on gas exchanges, fruit growth and carbohydrate contents at different stages of fruit development of Olea europaea L. 'Picholine'

The effects of different source-sink ratios on fruit quality were studied for the table olive cultivar ‘Picholine’. This cultivar represents 15% of the production of table olives in Tunisia. Fruit size is an important quality parameter for table olives as small fruits have lower economical value. Three tertiary branches/tree were selected on 27-years-old olive trees (10 trees in total) at the start of the growing season 2009. After fruit set in early May four fruit-to-leaf ratios were imposed on 1-year-old wood (no fruits, 1:1, 1:2, 1:3) of each branch. Apexes of all shoots were removed in order to reduce the vegetative sinks. In mid-July five trees were randomly selected and all branches were girdled. The absence of fruits or girdling decreased leaf net photosynthetic rate (An) and increased leaf carbohydrate contents. Girdling stimulated fruit growth, while the effect of leaf-to-fruit ratio was less pronounced

Study of phenolic composition of olive fruits: validation of a simple and fast HPLC-UV method

A high-performance liquid chromatography (HPLC) method endowed with a gradient elution and a UV detection system was established and validated for the determination of phenolic acids, phenolic alcohols, hydroxycinnamic acid derivatives, flavonoids, secoiridoids and lignans during olive (Olea europaea L.) fruit development (green, purple and black olives). Within the test range, the calibration curves exposed a good linear regression (R 2>0.9995). Detection limits ranged between 0.63 and 13.43 mg/L for the detected phenolic compounds. The presented method yielded satisfactory repeatability in terms of retention times and average concentrations of phenolic compounds (RSD < 0.3%). Verbascoside was established as the major phenolic compound in black olives. Oleuropein was established as the dominating phenolic compound in green olives, and its level decreased during maturation. Additionally, this research is the first to experimentally evidence that the flavone luteolin-7-rutinoside is the predominant flavonoid glucoside in black olives, showing the most significant variation with fruit development. The above results validate the method for an easy and fast determination of different classes of phenolic compounds present in olive fruits

A comparative study on chemical composition, antibiofilm and biological activities of leaves extracts of four Tunisian olive cultivars

Olea europaea L. is one of the most important fruit trees in Tunisia because of its content of many potentially bioactive compounds. The aim of this study was to evaluate the chemical composition, antibiofilm, antiradical and acethylcholinesterase inhibitory activities from four Tunisian cultivars of Olea europaea L., i.e. ‘Chetoui’, ‘Meski’, ‘Oueslati’ and ‘Jarboui’. By means of standardized methods, total phenols were determined and some of them characterized by HPLC. The total phenols and flavonoids contents were found to be the highest in the leaves of Chetoui cultivar. The Chetoui cultivar exhibited an important antioxidant and anticholinesterasic activity and an important anti-biofilm activity against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Candida albicans, Enterococcus faecalis and Escherichia coli, with percentages of inhibition comprised between 83 and 93% at 2xMIC values. Olive leaves extracts could be used in the control of bacterial biofilms in food and food-related&nbsp;environments.</p

Discrimination of some tunisian olive oil varieties according to their oxidative stability, volatiles compounds and chemometric analysis

Oxidation stability is a key property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by several factors such as cultivar and place of production. Polyphenols, carotenoids, chlorophylls, fatty acids levels and some volatiles were correlated to oxidative stability in olive oils in five samples studied. Total polyphenols and saturated to polyunsaturated fatty acids (and/or oleic to linoleic acid ratio) ratio were shown to be the major parameters in oil antioxidant stability, according to analysis of variance and principal component analysis. The hexanal/E-2-hexenal ratio is a very important indicator of the freshness of the oils and can estimate their oxidation degre

Modelling of water and energy exchanges over a sparse olive orchard in semi-arid areas

International audienceAbstract. In the Mediterranean basin, olive orchards occupy a large fraction of agricultural lands due to its sustainability to harsh conditions, drought in particular. Since most modeling tools to simulate vegetation functioning are not meant to represent very sparse crops (i.e., rainfed olive trees have a vegetation fraction cover ranging from 2 to 15 %), computing the water needs and the vulnerability to drought of an olive orchard is a challenge. There is indeed a very high contribution of the bare soil signal to the total fluxes, and it is difficult to decipher the contribution of the tree from that of the entire surface. In this context, in an attempt to study the olive tree hydrological functioning at field scale (38 ha), an experimental site was setup and a Soil–Vegetation–Atmosphere (SVAT) model has been applied. To represent the orchard soil–plant–atmosphere interactions, a simulation with default settings was assessed using parameters derived from both the literature and ground measurements. In this default configuration, neither the predicted actual nor the potential transpiration could reach the observed transpiration acquired during the wet season (R2 = 0.67, the Root Mean Square Error (RMSE) = 5.63 mm week−1). We show that the model fails to reproduce the relevant leaf surface that transpires. To address this issue and to improve the estimate of the year-to-year variability of the olive tree transpiration, we propose guidance on how a SVAT model can be modified to more appropriately represent the hydrological functioning of a sparse orchard. Once the tree transpiration is accurately simulated (R2 = 0.93, RMSE = 1.62 mm week−1), we evaluated whether the fully coupled (single patch) or a fully uncoupled (two patch) system better reproduced the total fluxes and their components. Owing to the independent characteristics of the soil columns inherent in the assumption of the 2-patch version, the bare soil column shows a deficiency if the topsoil root extraction is not accounted for. We deduced that we cannot accurately reproduce the soil evaporation in this configuration. This study open perspectives for a better representation of water fluxes over sparse tree crops into both hydrological and SVAT models

Modification of pomological characteristics and flavor components of fruits and virgin olive oil following wastewater irrigation and soil tillage

BACKGROUND The experiment was carried out on olive trees cv. Chemlali, during two successive years (2013/2014). Two irrigation treatments (IT: Trees irrigated with wastewater; TRC: Trees grown under rainfed condition) were combined with two tillage practices (TTS: Trees grown in tilled soil; TNTS: Trees grown in non-tilled soil). RESULTS The results of the study showed that WW irrigation combined with soil tillage improved the pomological characteristics of olive fruits. The tree yield increase was substantial for IT and TTS. However, most of the identified phenolic compounds, especially oleuropein, mainly accumulated in olive fruits of the TC block (TNTS + TRC), suggesting a marked improvement in the nutritional value of these fruits. Moreover, fruits of TNTS had high contents of sugar compounds, required for the synthesis of the fruit storage material. The study also showed that the agronomic practices affected the amounts of some aromatic compounds responsible for the distinctive flavor notes of olive oil. CONCLUSION Hence, agronomic practices may affect considerably the commercial and nutritional values and the sensorial quality of the commodities

Effect of three irrigation regimes on Arbequina olive oil produced under Tunisian growing conditions

This study investigated the effect of irrigation amount on the concentration of phenolic compounds in olive (Olea europaea L., cv. Arbequina) oil obtained from an intensively-managed orchard in a semi-arid area with a Mediterranean climate in Tunisia. Different irrigation treatments 50% Etc, 75% Etc and 100% Etc were applied to the olive orchard. Oil quality, evaluated using the parameters established to determine the quality level of virgin olive oils (acidity, K232, K270 and peroxide index) was slightly affected by irrigation. However, results showed that irrigation positively affected both fruit and oil quality. In fact, the least irrigation regime (T1), showed a significantly higher content of oleic acid (70.08%), whereas olive oils from more irrigated trees (T2 and T3) had higher contents of palmitic acid (11.64% and 13.14%, respectively) and lower of linoleic acid (approximately 12.7%). However, content of phenolic compounds (hydrophilic and lypophilic), in the oils extracted, strongly differed. In fact, different irrigation regimes applied not only affected the total amount of phenols which were proportional to irrigation (193.2 and 271.87mgkg-1 for T1 and T3, respectively) except for T2 but also their HPLC profiles. Contrarily to phenols, insignificant differences were observed in the concentration of [alpha]-tocopherol between the irrigation treatments studied.Fatty acids Virgin olive oil Phenols Pigments [alpha]-Tocopherol Sensory analysis Irrigation