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Inappropriate utilization of biosolids may adversely impact agrosystem productivity. This article addresses the response of H. vulgare and P. monspeliensis to different doses (0, 100, and 150 t ha−1) of municipal solid waste (MSW) compost in a greenhouse pot experiment. Plant growth, heavy-metal uptake, gas exchange, and photosynthetic pigment concentrations and photosynthesis parameters were considered. Results showed that compost supply significantly increased shoot and root dry weights of both species, and this was positively correlated with nutrient uptake. Chlorophyll and carotenoid contents were positively influenced, especially in H. vulgare at rate of 100 t ha−1. Furthermore, MSW compost application increased net photosynthetic rate (A), stomatal conductance (Gs), and water-use efficiency (WUE) in both species. Alternatively, MSW compost amendment increased plant heavy-metal contents but levels remained lower than phytotoxic thresholds. This preliminary study suggests that a MSW supply at moderate...

The present study aimed to investigate the efficiency of composted municipal solid wastes (MSWs) to reduce the adverse effects of salinity in two forages species, Polypogon monspeliensis (L.) Desf. and Hordeum vulgare L., and their direct effect on plant hormonal status. Plants were cultivated in the greenhouse using pots filled with saline soil (EC = 5.13 dS m −1 ) supplemented with 100 and 150 t ha −1 of MSW compost or without compost that was used as control, and irrigated twice a week with tap water. Biomass production, leaf number and root length were determined at the end of the experiment. We also analyzed contents of potential toxic (Pb 2+ , Zn 2+ , and Cu 2+ ) elements and seven major plant hormones (abscisic acid, ABA; the cytokinins (CKs) zeatin, Z; and zeatin-riboside, ZR; the auxin indole-3-acetic acid, IAA; jasmonic acid, JA; salicylic acid, SA and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, ACC) in roots and shoots. The application of MSW compost increased shoot biomass in both species up to 47%, as well as the number of leaves per plant and root length. The increase in root growth was apparent in both P. monspeliensis genotypes than H. vulgare . In general, MSW compost addition decreased ACC concentration in the shoots and roots of studied species. By contrast, CKs substantially increased in shoots especially in both P. monspeliensis genotypes. Auxin indole-3-acetic acid concentration was higher in the shoots of P. monspeliensis from the north region than in H. vulgare and P. monspeliensis derived from the south region. It is suggested that increased CK content and its transport from the root to the shoot were probably induced by the basipetal transport of auxin from the shoot to the roots. This study suggested that the MSW supply at moderate doses (100 t ha −1 ) could be highly beneficial for the cultivation of crops such as P. monspeliensis and H. vulgare in saline soils by adjusting plant hormonal balance.

The differences in the chemical composition of virgin olive oils (VOO) obtained from trees of the Chetoui variety cultivated at different altitudes in Tunisia were evaluated. All samples were harvested using the same controlled procedures and were submitted to a controlled processing in the same laboratory mill. Several analytical parameters such as fatty acid composition, amounts of phenols; o-diphenols and pigments were analyzed. All these parameters showed an important effect on the fatty acids and phenols content of the oils. The total phenol content was positively correlated with the altitude, ranging from 817.33 mg/kg (403 m) to 131.91 mg/kg (10 m). However, the results of the regulated parameters in the potential quality classified all the analyzed oils into the ‘‘extra virgin’’ category. Key words : Orchard elevation, total antioxidant capacity, phenolic compounds, quality index.

The aim of the present work was to investigate the influence of fruit ripening on oil quality and volatile compounds in an attempt to establish an optimum harvesting time for Oueslati olives, the minor olive variety cultivated in Tunisia. Our results showed that many analytical parameters, i.e., peroxide value, UV absorbance at 232–270 nm, chlorophyll pigments, carotenoids and oleic acid contents decreased during ripening, whilst linolenic acid increased. Free acidity remained practically stable with a very slight rise at the highest maturity index. The volatile compounds emitted by the Oueslati olive oil were characterized and quantified by HS-SPME-GC-EIMS. Twenty-three volatile compounds were identified, mainly aldehydes, sesquiterpenes and esters. The results show variations in the volatile fractions and quality parameters of Oueslati extra virgin olive oil obtained at different olive-ripening stages. Fifteen sesquiterpenes were identified for the first time in this cultivar, mainly hydrocarbon derivatives, but also oxygenated ones. On the basis of the quality parameters and volatile fractions studied, the best stage of Oueslati olive fruits for oil processing seems to be at ripeness index about 3.0. Indeed, these results suggested the possibility of using sesquiterpenes for olive authenticity and traceability and demonstrated that the volatile fractions can be used as indicators of the degree of ripening of the olives used to obtain the corresponding virgin olive oils.

Organic wastes were successfully used as soil amendment to improve agrosystems productivity. Yet, the effectiveness of this practice to enhance plant antioxidant capacities has received little attention. Here, we assess the effect of municipal solid waste (MSW) compost (at 40 t ha−1) on growth, polyphenol contents and antioxidant activities of Mesembryanthemum edule. MSW compost application significantly increased the soil contents of carbon, nitrogen, calcium, phosphorus and potassium. This was associated with higher nutrient (N, P, and K) uptake, which likely led to the significant improvement of the plant biomass and relative growth rate (RGR) (+93% on average) as compared to the control. In the same way, the fertilizing effect of the added organic matter significantly enhanced the antioxidant potential M. edule, assessed by radical scavenging activity, iron reducing power and β-carotene bleaching capacity. This was associated with significantly higher antioxidant contents, mainly total phenols and flavonoids. Heavy metal (Pb, Cd, Cu, and Zn) concentrations were slightly increased upon compost application, but remained lower than phytotoxic values. Overall, our results point out that short-term MSW compost application at 40 t ha−1 is efficient in enhancing the productivity together with the antioxidant potentiality of M. edule without any adverse environmental impact.

Summary The main triglycerides (TG) identified in the Oueslati virgin olive oil were 1,2,3-trioleylglycerol (OOO), 2,3-dioleyl-1-palmitoylglycerol (POO) and 2,3-dioleyl-1-linoleylglycerol (LOO) representing more than 80% of the total area of peaks in the chromatogram. Other minor triacylglycerols were 2,3-dioleyl-1-stearoylglycerol (SOO), 2-oleyl-3-palmitoyl-1-stearoylglycerol (SOP), 1-linolenoyl-2-oleyl-3-palmitoylglycerol (LnOP), 1, 2-dilinoleyl-3-palmitoylglycerol (LLP), 1, 3-dioleyl-2-linolenoylglycerol (OLnO), 1-linolenoyl-2-linoleyl-3-oleylglycerol (LnLO) and 1,2,3-trilinoleylglycerol (LLL). The sterol profile of Tunisian virgin olive oils produced from Oueslati cultivar was established by gas chromatography using a flame ionisation detector (GC-MS). More than 10 compounds were identified and characterised. As expected for virgin olive oil, the main sterols found in all Oueslati olive oils were β-sitosterol, Δ5-avenasterol, campesterol and stigmasterol. Cholesterol, 24-methylenecholesterol, clerosterol, campestanol, sitostanol, Δ7-stigmastenol, Δ5, 24-stigmastadienol and Δ7-avenasterol were also found in all samples, but in lower amounts. Most of these compounds are significantly affected by the geographical origin of the oil. Besides the sterol components, two triterpene dialcohols, erythrodiol and uvaol, were also detected.

The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg−1 for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg−1, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive oil was observed in the Koroneiki cultivar (0.24 mmol TE kg−1) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg−1) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid profile which are important for its shelf life.

BACKGROUND: The aim of the present work was to investigate the influence of fruit ripening on oil quality in an attempt to establish an optimum harvesting time for Chetoui olives, the second main olive variety cultivated in Tunisia. RESULTS: Our results showed that many analytical parameters, i.e., peroxide value, UV absorbance at 232 and 270 nm, chlorophyll pigments, carotenoids and oleic acid contents decreased during ripening, whilst oil content and linolenic acid increased. Free acidity remained practically stable with a very slight rise at the highest maturity index. The trend of oxidative stability, total phenols and o-diphenols, showed an increase at the early stages followed by a reduction at more advanced stages of maturity. The major phenolic compounds, such as hydroxytyrosol, ligstroside aglycon, elenolic acid, acetoxy-pinoresinol and oleuropein aglycon, seemed to have the same behaviour. In the case of tyrosol, a strong decrease was observed directly related with the ripening progress. CONLUSION: On the basis of the evolution of the analytical parameters studied, the best stage of Chetoui olive fruits for oil processing seems to be at ripeness index higher than 2.0 and lower than 3.0. Copyright © 2009 Society of Chemical Industry

The olive oil content in phenolic compounds depends on the variety of the fruit used for its extraction as well as on the predominant climate conditions in the tree cultivation area. Here, we report on the characterization of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivars Chemlali and Chetoui, grown in three different Tunisian locations, Zaghouan (North), Sousse (Center) and Sfax (South). Chetoui olive oil samples obtained from fruits of olive trees cultivated in Zaghouan and Chemlali olive oil samples obtained from fruits of olive trees cultivated in Sousse were found to have a higher mean total phenol content (1004 and 330 mg/kg, respectively). Olive oil samples obtained from fruits of both cultivars had different phenolic profiles and a higher content in 3,4-DHPEA-EDA when the olive trees were cultivated in Zaghouan. Both olive cultivars were found to have different responses to environmental conditions. Chetoui olive oil showed decreased oxidative stability when the fruits were obtained from olive trees cultivated in the center of Tunisia (34.8 h) and in Sfax (16.17 h). Furthermore, statistical data showed that the phenolic composition and oxidative stability of Chetoui olive oil varied more by location than those of Chemlali olive oils.

Chemlali olive oil was blended with oils obtained from Oueslati and Chetoui varieties to improve the quality of the former one. Parameters such as triacylglycerols and phenolic compounds were characterized for various blends of Chemlali x Oueslati and Chemlali x Chetoui. Results show that blended oils had an improved composition as compared to that of Chemlali. In fact, the highest percentage of Oueslati and Chetoui olive oils (60% of blending) could lead to 1,2,3-trioleylglycerol (OOO) of up to 30.20 and 33.44%, respectively. The amount of aldehydic form of oleuropeine aglucon was higher when Chemlali was blended using either 40 or 60% of Chetoui olive oil (from 99.17 to 299.63 and 334.16 mg kg -1 ). Key words: Oil blending, Chemlali x Oueslati, Chemlali x Chetoui, phenolic fraction, triacylglycerols African Journal of Biotechnoloy , Vol 13(12), Vol 1386-1392

The effectiveness of compost supply at several doses (0, 50, 100, and 150 t/ha) to a saline soil was studied using municipal solid waste (MSW) and palm waste (PW) composts. The experiment was carried out in pots under cultivation of Polypogon monspeliensis (halophyte forage species) and Hordeum vulgare (common forage species) and lasted three months. The investigation focused on some selected soil physico-chemical properties, soil microbial biomass, and ten soil enzymatic activities; Arylsulfatase (ARY), dehydrogenase (DEH), β-glycosidase (β-GLU), protease (PRO), urease (URE), invertase (INV), Fluorescein diacetate hydrolase (FDAH), catalase (CAT), acid and alkaline phosphatases (PHO). Both amendments improve markedly the saline soil quality. They ameliorate the physico-chemical properties. The increase of soil pH is regarded as an interesting fact and is usually proportional to the compost application rate. Electrical conductivity increased proportionally to the applied rates. Soil carbon and nitrogen amounts were also improved and the highest raise (7.5-folds) was noted for carbon. According to the substantial increase of the organic matter, levels of measured microbial biomass and several enzyme activities in saline soil were improved. DEH activity which proposed as a measure of overall microbial activity exhibited a significant increase only at dose 2 (100 t/ha). Consequently, One hundred tones of composts per hectare, under which some enzymes exhibited an optimal of activity and metal accumulation can be minimized, appeared an interesting rate for saline soil amendment.

Chetoui and Chemlali olive fruits were stored at two different temperatures (ambient and 5°C) for different periods before oil extraction at 0, 7, 14, 21 and 28 days to investigate the effect of postharvest fruit storage on olive oil quality. Conventional analyses (acidity, peroxide value, specific extinction coefficient at 232 and 270 nm and fatty acid composition) and non conventional analyses (pigments, total phenols, oxidative stability and radical scavenging capacity) were carried out in order to evaluate the oil quality. Results showed that fruit storage at ambient temperature led to the deterioration of the oil parameter qualities such as acidity, K232 and K270 which is more rapidly in Chemlali oils than that of Chetoui cultivar. In the same way, the trend of total phenols, oxidative stability and radical scavenging capacity of the studied olive oils showed a decrease during the fruit storage at ambient temperature. This reduction was more severe in Chemlali olive oils than those of Chetoui cultivar. Storage of fruits at 5°C prevented the fast alteration that is produced in oils extracted from fruits stored at ambient temperature. Key words: Olive storage, oil quality, fatty acids, stability.

The present study focused on the comparison the chemical composition of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivar (Chemlali) grown in four planting densities (156, 100, 69, and 51 trees ha−1). Despite the variability in the triacylglycerols and volatile compounds composition, the quality indices (free fatty acids, peroxide value, and spectrophotometric indices K232and K270) all of the virgin olive oils samples studied met the commercial standards. Decanal was the major constituent, accounting for about 30% of the whole volatiles. Moreover, the chemical composition of the volatile fraction of the oil from fruits of trees grown at the planting density of 156, 100, and 51 trees ha−1was also characterised by the preeminence of 1-hexanol, while oils from fruits of trees grown at the planting density of 69 trees ha−1had higher content of (E)-2-hexenal (20.3%). Our results confirm that planting density is a crucial parameter that may influence the quality of olive oils.

The aim of the present investigation is to discriminate five minor Tunisian olive cultivars ( Hor Kesra , Sredki , Chladmi , Betsijina and Aloui ) by studying their sterol and phenol compositions. This is the first study of the chemical composition of virgin olive oils (VOO) from these cultivars. The majority of analytical parameters presented statistically significant differences ( P Betsijina oil was characterized by high mean values of total phenols (1400 mg kg −1 ) and oxidative stability (113 h). VOOs studied demonstrate that the differences in phenols (min: 253–max: 1400 mg kg −1 ), tocopherol (139–402 mg kg −1 ), sterols (1039–1567 mg kg −1 ), triterpene dialcohols (19.1–32.4 mg kg −1 ) and triacylglycerols profiles may be explained by genetic factors. Results of PCA and HCA analyses show a good discrimination between varieties according to phenol, triacylglycerol and sterol data. These components seem to be an effective tool to discriminate between the varieties.

The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive LC-ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas. In the Tunisian samples, 22 compounds have been characterised by LC-ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region.

The aim of the present work was to investigate the influence of fruit ripening on oil quality in an attempt to establish an optimum harvesting time for Chétoui olives, the second main olive variety cultivated in Tunisia.Our results showed that many analytical parameters, i.e., peroxide value, UV absorbance at 232 and 270 nm, chlorophyll pigments, carotenoids and oleic acid contents decreased during ripening, whilst oil content and linolenic acid increased. Free acidity remained practically stable with a very slight rise at the highest maturity index. The trend of oxidative stability, total phenols and o-diphenols, showed an increase at the early stages followed by a reduction at more advanced stages of maturity. The major phenolic compounds, such as hydroxytyrosol, ligstroside aglycon, elenolic acid, acetoxy-pinoresinol and oleuropein aglycon, seemed to have the same behaviour. In the case of tyrosol, a strong decrease was observed directly related with the ripening progress.On the basis of the evolution of the analytical parameters studied, the best stage of Chétoui olive fruits for oil processing seems to be at ripeness index higher than 2.0 and lower than 3.0.

In the present work, we studied the effectiveness of the predominant halophytes of Soliman sabkha (Tecticornia indica and Suaeda fruticosa) to promote soil biological activities and ecosystem productivity. Soil Arylsulphatese ARY, beta-glucosidase beta-GLU, phosphatase PHO, invertase INV, urease URE, and dehydogenase DES activities in Extra- and Intra-tuft halophytes and plant productivity were assessed. Results revealed a high increase of microbial community and ARY, beta-GLU, PHO, INV URE and DES activities (+298%, +400%, +800%, +350%, +320%, +25% and +759%, respectively) in Intra-tuft rhizosphere as compared to Extra-tuft one, which is likely due to the significant decrease of salinity in the rhizosphere of Tecticornia indica and Suaeda fruticosa. Both perennial plants exhibited high productivities (7.4 t dry weight ha(-1) and 2.2 t dry weight ha(-1), respectively) and Na+-hyperaccumulating capacities (0.75 t Na+ ha(-1) and 0.22 t Na+ ha(-1), respectively), reducing salt constraint and favouring soil fertility. This constitutes a promising alternative to enhance productivity in such a salt-affected biotope by offering suitable microhabitat for annual glycophytes.