Extraction of oil from jatropha seeds using a twin-screw extruder: Feasibility study

The objective of this study was to evaluate the feasibility of mechanical pressing to extract oil from jatropha seeds using a twin-screw extruder. Experiments were conducted using a co-rotating (Clextral BC 21, France) twin-screw extruder. The influence of operating conditions on oil yield, specific mechanical energy and oil quality was examined. Operating conditions included screw configuration, pressing temperature and screw rotation speed. Generally, it was the screw configuration, or profile, that most affected oil extraction efficiency. The best oil yields, a minimum 57.5%, were obtained with a trituration zone composed of 10 monolobe and 10 bilobe paddles, and a pressing zone composed of 50 mm long, reverse pitch screws with a −33 mm pitch. In addition, oil extraction yield increased with decreasing temperature and screw rotation speed. Highest oil extraction yield (70.6%) with good press cake quality (residual oil content lower than 8%) was obtained under operating conditions of 153 rpm screw rotation speed, 5.16 kg/h inlet flow rate of jatropha seeds, and 80 ◦C pressing temperature. The corresponding expressed oil was inexpensive to produce (71 W h/kg seed processed or 314 W h/kg expressed oil for specific mechanical energy) compared with another continuous technique, i.e. the single expeller press, commonly used for mechanical extraction of jatropha oil. Its quality was also satisfactory for biodiesel production. The acid value, the density and the kinematic viscosity were 5.4 mg of KOH/g of oil, 915 kg/m3 and 36.7×10−6m2/s, respectively

Sterol concentration and distribution in sunflower seeds (Helianthus annuus L.) during seed development

Sunflower seeds are currently used for edible oil production. Among oil minor compounds, phytosterols are of special interest due to their cholesterol reducing properties. This paper reports studies on their accumulation and distribution in the embryo and hull, and the effects of temperature on phytosterol contents in sunflower seed produced under both conventional and organic field conditions. An optimized method of sterol determination, adapted to studies on small samples of seed, is presented. Seventy-two % of phytosterols were found in the embryo, 28 % in the hull. The periods of phytosterols concentration varied according to sterol category and seed part. Application of these results to improve production of natural sterols for functional food use is discussed

Effects of genotype and sowing date on phytostanol-phytosterol content and agronomic traits in wheat under organic agriculture

Cereals are an important source of sterols and stanols in the human diet. The present study underlines the effect of genotype and weather conditions in bread wheat, on total sterol and stanol content (TSS), agronomic traits, proteins and ash content under organic conditions. Variations in TSS as well as other characters between two sowing dates were observed. A broad genotypic variability was also reported since extreme genotypes differed by more than 30 mg 100. g-1 DW for TSS, with total stanol content varying twofold. Moreover, two groups of genotypes that differed in agronomic production, ash and protein content were depicted, based on their response to an increase in temperature. This result suggests that the genotypic factor prevails over the sowing date factor for determining sterol and stanol traits in wheat cultivated under organic conditions. Nevertheless, a strong interaction exists between the two factors, which can be used to drive bioaccumulation of these molecules

Sterol content in sunflower seeds (Helianthus annuus L.) as affected by genotypes and environmental conditions

Phytosterols play essential roles in many plant cell mechanisms. They are of industrial interest since, as part of the diet, they can reduce Low Density Lipoprotein cholesterol. An increase in plant sterol contents by improved crop varieties or crop management could help to answer industrial demands and also to develop environmentally friendly extraction methods. The aim of this study was to evaluate genotypic variability for sterol content in cultivated sunflower and effects of sowing date, in particular sowing date. Results showed large variability among a collection of sixteen sunflower inbred lines and hybrids. Total sterols varied almost twofold between extreme genotypes. A delay of sowing, giving higher temperatures during seed formation, induced a general increase in total sterol concentration by up to 35 per cent, as well as sterol composition but this varied according to genotype. These results are discussed with the aim of improving sterol content by sunflower breeding programmes

Fatty acid and phytosterol accumulation during seed development in three oilseed species

This study was carried out to compare the kinetic accumulation of bioactive lipids during seed development in three oil crops rapeseed, sunflower and woad. Field experiments were conducted under organic conditions during 3 years. After flowering, seeds were collected each 4–5 days until harvest. The three species differed by the quantity and quality of both fatty acids and sterols. Higher levels of phytosterols and fatty acids were reached between 20 and 40 days after flowering (DAF) in sunflower, 40 and 60 DAF in rapeseed and 25 and 45 DAF for woad. The modification of lipid composition during the grain filling depends on species. Knowledge of the composition and accumulation of fatty acids and phytosterols in sunflower, rapeseed and woad seeds would assist in efforts to achieve industrial applications. These seeds may give an interesting source of bioactive lipids

Oil and fatty acid accumulation during coriander (Coriandrum sativum L.) fruit ripening under organic cultivation

To evaluate the accumulation of oil and fatty acids in coriander during fruit ripening, a field experiment was conducted under organic cultivation conditions in Auch (near Toulouse, southwestern France) during the 2009 cropping season. The percentage and composition of the fatty acids of coriander were determined by gas chromatography. Our results showed that rapid oil accumulation started in early stages (two days after flowering, DAF). Twelve fatty acids were identified. Saturated and polyunsaturated acids were the dominant fatty acids at earlier stages (2–12 DAF), but decreased after this date. After this stage, petroselinic acid increased to its highest amount at 18 DAF. In contrast, palmitic acid followed the opposite trend. Saturated and polyunsaturated fatty acids decreased markedly and monounsaturated fatty acids increased during fruit maturation. It appears that the fruit of coriander may be harvested before full maturity

Recovery of slaughterhouse Animal Fatty Wastewater Sludge by conversion into Fatty Acid Butyl Esters by acid-catalyzed esterification

Two types of Animal Fatty Wastewater Sludges (AFWS 1 and 2) were analyzed and fully characterized to determine their suitability for conversion into biofuel. AFWS 1 was determined to be unsuitable as it contains 68.8wt.% water and only 32.3wt.% dry material, of which only around 80% is lipids to be converted. AFWS 2 has only 15.7wt.% water and 84.3wt.% dry material of which is assumed to 100% lipids as the protein and ash contents were determined to be negligible. The 4-dodecylbenzenesulfonic acid (DBSA) catalyzed esterification of AFWS with 1-butanol was performed in a novel batch reactor fitted with a drying chimney for the “in situ” removal of water and optimized using a non-conventional Doehlert surface response methodology. The optimized condition was found to be 1.66mol equivalent of 1-butanol (with respect to total fatty acid chains), 10wt.% of DBSA catalyst (with respect to AFWS) at 105°C for 3h. Fatty Acid Butyl Esters (FABEs) were isolated in good yields (95%+) as well as a blend of FABEs with 1-butanol (16%). The two potential biofuels were analyzed in comparison with current and analogous biofuels (FAME based biodiesel, and FABE products made from vegetable oils) and were found to exhibit high cetane numbers and flash point values

Phytoconstituents of leaf extracts of Ziziphus jujuba Mill. plants harvested in Tunisia

The present study aimed to determine the phytoconstituent compositions of the leaves of four Ziziphus jujuba ecotypes (Choutrana, Mahdia, Mahres and Sfax). The chromatographic peaks of 18 compounds, including nine major fatty acids, five sterols, two triterpene alcohols and two methysterols, were quantified by the capillary gaseous chromatography method. The major fatty acids identified were linolenic (42.04%) and palmitic (23.04%). Unsaturated fatty acids ranged between 53% and 60%. The predominant sterols (mg/100g) were β-sitosterol (40.36) and stigmasterol (24.18). Cycloartenol (68.55mg/100g) and citrostadienol (12.27mg/100g) were the major metylsterols. Methylene cycloartanol ranged between 1.2mg/100g (Sfax) and 1.5mg/100g (Mahdia). Total phenolic content measured by Folin-ciocalteux ranged from 3.97mg GAE/g to 6.04mg GAE/g. The predominant flavonoids identified by HPLC were apigenin (6.1mg/g) and rutin (1.91mg/g). The fatty acids and flavonoids in the Z. jujuba leaves were responsible for their therapeutic and pharmaceutical effects. This could explain why Tunisian people traditionally use it as medicine to treat several pathologies

Effect of methylene blue on the formation of oxidized phospholipid vesicles

Soybean phosphatidylcholine, which is rich in linoleic acid, was oxidized with singlet oxygen through photosensitization with methylene blue. This compound facilitates the oxidation of phospholipids relative to the reaction with free unsaturated fatty acids. A response surface methodology was used to control oxidation, with methylene blue concentration and the amount of available air as independent variables. The conjugated diene-to triene ratio was then monitored. Hydroperoxide yield dependent principally on the amount of air, whereas photosensitizer concentration strongly influenced the size and zeta potential of vesicles formed by the sonication of oxidized phospholipids in water. Methylene blue plays an important role in the surface charge expression and ion permeability of these vesicles

Characterization of french coriander oil as source of petroselinic acid

Coriander vegetable oil was extracted from fruits of French origin in a 23% yield. The oil was of good quality, with a low amount of free fatty acids (1.8%) and a concurrently high amount of triacylglycerols (98%). It is a rich source of petroselinic acid (C18:1n-12), an important renewable building block, making up 73% of all fatty acids, with also significant amounts of linoleic acid (14%), oleic acid (6%), and palmitic acid (3%). The oil was characterized by a high unsaponifiable fraction, comprising a substantial amount of phytosterols (6.70 g/kg). The main sterol markers were β-sitosterol (35% of total sterols), stigmasterol (24%), and Δ7-stigmastenol (18%). Squalene was detected at an amount of 0.2 g/kg. A considerable amount of tocols were identified (500 mg/kg) and consisted mainly of tocotrienols, with γ-tocotrienol as the major compound. The phospholipid content was low at 0.3%, of which the main phospholipid classes were phosphatidic acid (33%), phosphatidylcholine (25%), phosphatidylinositol (17%), and phosphatidylethanolamine (17%). About 50% of all phospholipids were non-hydratable. The β-carotene content was low at 10 mg/kg, while a significant amount of chlorophyll was detected at about 11 mg/kg. An iron content of 1.4 mg/kg was determined through element analysis of the vegetable oil. The influence of fruit origin on the vegetable oil composition was shown to be very important, particularly in terms of the phospholipids, sterols, and tocols composition21