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This article constitutes the third instalment in a comprehensive series dedicated to the comparative analysis of solvent solutions for oilseeds extraction. With some adaptations, all solvents considered except methanol would allow complete extraction of the meals. Nonpolar solvents such as hexane are penalized by their hydrophobicity in penetrating biological matrices, but their immiscibility with water makes their recycling simple and efficient. Their low energy requirement for evaporation and the use of live steam for final residue elimination are advantageous. Dichloromethane is similar to hexane in its low miscibility with water and high volatility, but its higher density could disrupt percolation by compacting the material bed. Ethyl acetate and 2-methyloxolane have limited miscibility with water, allowing for simple removal of process water, but residual water promotes higher solvent retention in the marc, making the desolventizer’ s task more difficult and requiring higher solvent-to-solid ratios. Saturated methyl ethyl ketone contains even more water, potentially exacerbating these problems. Acetone, as well as ethanol and isopropanol, are completely miscible with water, thus prohibiting the separation of process water and requiring additional process steps such as pervaporation for alcohols and rectification for acetone. Substantial energy savings are possible with these solvents by separating oil from the miscella through cold precipitation, particularly in the case of ethanol, which has low miscibility with oil. An additional operation is the drying applied to the incoming material. Each solvent family therefore presents specific challenges and advantages, requiring tailored solutions to optimize extraction while maintaining efficiency, profitability, and product quality.

While it is clear that solvent extraction (SE) dominates the vegetable oil production sector because of the higher yields it allows, it is more difficult to estimate the difference in added value (AV) between this production method and extraction by mechanical means alone (ME). The aim of this article is to propose an objective method for assessing this differential by addressing the question of assessing the material balances associated with each process and the issue of the value of expeller cakes in different economic contexts, an assessment made necessary by the absence of regular public quotations for these feedstuffs. Material balances are determined by the oil content in the seeds and the oil residues left in SE meals and ME cakes. Based on 100 kg of seeds, oil production was estimated at 43.7 and 44.9 kg using the SE process compared with 39.3 and 38.8 kg using the ME process for rapeseed and sunflower respectively. To assess the value of expeller cakes, we used a basket of feedstuffs with known quotations and nutritional value to determine an equation for price prediction within 35 market conjunctures between June 2008 and May 2024. These predictions were used to establish a linear correlation between hexane meal prices and predicted expellers prices allowing a calculation of the added value in 574 market situations from 2010 to 2024. A linear regression shows that AV of ME is equal to 0.71 AV of SE + 6.8 €/t for rapeseed and 0.63 AV of SE + 2.1 €/t for sunflower.

As there is a lack of regulations on pesticide levels in crude oils, this study aimed to evaluate transfer factors for extrapolating concentration limits established for maize kernels to the crude oils extracted from their germs. Maize kernels were spiked with 4 organophosphates insecticides (chlorpyriphos, chlorpyriphos-methyl, fenitrothion, pirimiphos-methyl), 2 pyrethroids (cypermethrin and deltamethrin) and a pyrethroid synergist, piperonyl butoxide (PB) targeting a dose of 1 mg/kg grain. The kernels were transformed in a pilot starch-mill to separate the germs (wet-milling) then these germs underwent an oil extraction process in a mini-pilot comprising a thermal conditioning stage, a mechanical extraction followed by a solvent extraction and a desolventization-toasting stage for the meal. Analyses were carried out by gas chromatography coupled to MS/MS detector. The pesticides content was measured on kernels, spiked kernels, germ, crude oil and meal. Surprisingly, a significant difference in behavior was observed between organophosphates and pyrethroids in the transition from grain to germ. For the former, the applied pesticides were recovered at levels between 48% and 81% in the germ, compared to only 9–11% for the latter and 31% for PB. It has been shown by means of acetonitrile washing on spiked seeds that the pyrethroids remained bound to the hydrophobic cuticle of the grains. On the other hand, from the germ to the oil, the initial hypothesis of an almost total transfer of the pesticides in the fat fraction of the material was confirmed. The germ to meal concentration ratios were on average 0.019, 0.065 and 0.109 for organophosphates, PB and pyrethroids respectively. In the same order, the concentration ratios between germ and crude oil were 1.87, 1.98 and 2.17. Grain to final oil transfer factors ranged from 7.4 to 12.7 for organophosphates, 4.8 for PB and 1.4 and 1.7 for cypermethrin and deltamethrin respectively.

Quantitative information on the concurrent changes in major rumen microbial functions induced by dietary lipids in relation with the degree of unsaturation of fatty acids is scarce. During a three-period essay (9 days per period), rapeseed (Brassica napus L., RO), sunflower (Helianthus annuus L., SO) and linseed (Linum usitatissimum L., LO) oils at the high level of 80 g/kg dry matter input (DMI) and a control without oil were compared in four 1-L dual outflow fermenters inoculated with bovine rumen microbiota and maintained on a maize silage-based diet. Neither the fermentation medium pH and redox potential nor starch and protein degradabilities were significantly altered. Oil supply significantly decreased butyrate and methane specific productions of to the benefit of propionate and hydrogen specific productions and decreased the microbial protein outflow and synthesis efficiency while increasing the outflows of ammonia and isovalerate, these effects being amplified by the fatty acids’ unsaturation degree. Besides, with no impact of the degree of unsaturation, oil supply increased the amount of fermented hexose, the productions of all SCFAs except butyrate and the specific production of acetate. The rumen variables apparently sensitive to oil unsaturation degree were thus related either to metabolic hydrogen removal pathways or to protein metabolism.

In a context where the search for naturalness, the need to reduce the carbon footprint and the development of a decentralized crushing sector are intensifying, mechanical extraction is a technology that is regaining major importance for the industry. The performance of this technique remains far below what is desirable, while the understanding of the main phenomena involved in screw presses remains insufficient. This article, after a brief presentation of the state of the art of this discipline, presents a new model centered on the notions of pressure generation and plasticity. According to this approach, plasticity can account for parameters such as the water and oil content of oilseeds, their temperature, and their possible dehulling. Plasticity in turn would explain both the compressibility of the cake and its ability to resist the thrust of the screws, and consequently to generate pressure or to creep or flow backward depending on the geometry of the screw and the cage. The model must also incorporate the notions of compression velocity, friction, and the complexity of the interactions between these parameters and the impact of the succession of screw segments and cone rings. It has been built on observation and experience and gives an understanding of the need to work simultaneously on the conditioning and geometry of the presses to achieve improved performance in terms of energy, efficiency, and reduction of the temperatures experienced by the proteins and oils

The crushing industry is called upon to modify its processing methods in response to a rising demand for vegetable proteins, while at the same time increasing transparency and naturality. Changing the processes without taking this request into account would mean risking rejection and failure. The social sciences have shown that the collective unconscious inextricably links the notion of naturalness to healthy eating, respect for the environment, and social honesty. However, this notion goes beyond what’s rational and proves difficult to pin down when it comes to evaluating products. France does not recognize the ISO data sheet that defines what a “natural” ingredient is. Yet we do need a standard, if only to make informed choices between different possible technological paths. This standard of reference could be inspired by available norms in related fields, or it could be based on the best available technologies within a framework that takes into account both societal aspirations and the technical and economic possibilities of the industrial world. To achieve this, the sector’s representative bodies, the State, and consumer advocate groups should engage in a collective approach.

The move towards more sustainable production and consumption patterns is a goal shared by a large part of society. In the oil-mill sector, whether it be animal feed or human food, this development should make it possible to improve the protein autonomy of the territories and to use proteins more efficiently. Current methods make some of the rapeseed proteins indigestible and leave most of the undesirable compounds from the seeds in resulting meals. Residual oil, fibrous envelopes, glucosinolates, phytic acid, phenolic compounds and oligosaccharides, as well as overcooking, however, have negative effects on the value of proteins. An important part of the article is devoted to reviewing these effects. Their extraction, combined with milder heat treatments, would provide excellent quality proteins to the market and generate value for the entire value chain. Efficient dehulling and mechanical extraction would be the prerequisites for this development. An ethanolic extraction revisited to exploit the secondary metabolites would then complete this process with, however, a limited effect on phytic acid. All these technologies have the advantage of not posing major acceptability problems. This development requires new investments in applied research to make this new approach to processing oilseeds possible and efficient.

Solvents have a bad reputation in the cosmetics world, at least as regards the production of specialty vegetable oils used in this market. In order to do without these solvents, the cosmetics industry tends to use only mechanically produced oils. However, there is a range of seeds for which mechanical extraction is not satisfactory. This is the case with rare, expensive, and oil-poor seeds for which pressing does not give good yields, and results in high production costs. These are also hard seeds that cannot be pressed without causing the presses to become intensely hot, and this affects the quality of the oils. In recent years, our laboratory has worked on the development of extraction techniques with ethanol and the EcoXtract® solvent (2-methyloxolane) in order to provide professionals with production methods compatible with the COSMOS standard. Ethanol is not a good solvent for oils, especially in the presence of water and at low temperature. This drawback can be turned into an advantage to recover the oil (without distillation of the solvent) by cold decantation. The extraction is carried out on the hot components, and the oil is recovered by cooling the saturated miscella for the precipitation of the lipid phase. This process makes it possible to limit the energy consumption necessary for the recovery of the oil and the regeneration of the solvent. The great advantage for oils intended for the cosmetic market is that ethanol has a better solvent power for polar lipids compared to hexane and mechanical extraction. It is possible to split the lipid extract into neutral lipids and polar lipids by adjusting the precipitation temperature or by partial distillation. At the refining step, it is also possible to deacidify and remove contaminants from crude oil by liquid-liquid extraction with ethanol. We have recently obtained interesting results by reducing the phthalate concentration of walnut oils by 90%. The use of ethanol for oil neutralization is a process which generates less loss of neutral oil than the alkaline neutralization of a mixture with high acidity, and this is less harmful than physical refining during the production of 3-MCPD esters, esters of glycidol, and trans fatty acids. EcoXtract® is a solvent derived from the chemistry of pentoses in biomass. This solvent has very good oil solvation capacities and less biological toxicity than hexane. Its production has an acceptable carbon footprint and good sustainability characteristics. It is recognised by Ecocert as suitable for producing COSMOS ingredients. Compared to ethanol, its use requires fewer preparation steps (ethanol requires rigorous drying before extraction) and it requires less circulating solvent per kilo of oil extracted. The solvent removal from the meal requires less energy and allows the use of direct steam to aid in the removal of the solvent since the miscibility of water in this solvent is limited to 4.5 g/100g.

The loss of fats in the hulls is one of the main obstacles limiting the industrial implementation of rapeseed dehulling. The main reason resides in the shape of rapeseed outer cotyledons which resemble to the hulls’ shape and make it difficult to separate. The purpose of this study is to propose a new method for the purification of rapeseed hulls. After primary separation by aspiration, the mixture of hulls and kernels is passed between a pair of flat rolls where kernels are flattened and stick to the metal while the hulls do not. We exploited this property to adapt a small laboratory flaker with two counter-rotating cylinders of 65 mm diameter with scrapers that make the kernels fall away from the hulls. Process optimization by tunning experimental conditions (hulls moisture content, roller spacing, roller speed and feed rate) allowed the determination of the optimal operating conditions. Experiments showed that wetting improves the purity of the hulls but reduces the one of the recovered kernels. A gap of 0.1 mm was necessary. In addition, it was shown that the sorting quality depends on the ratio flow-rate / rotation-speed. The best performances are reached around 1 g.s−1.rpm−1. In these conditions, the hulls and kernels purity were 96% and 94% respectively. This preliminary work has allowed us to prove the concept. The next step will be to develop a pilot plant to validate the process efficiency on a larger scale (100 kg/h).

Liquid–liquid extraction of vegetable oil with ethanol predominantly removes the components having the greatest affinity for ethanol, such as free fatty acids responsible for the acidity of oil, but also some contaminants such as phthalates. The aim of this work is to study the effect of several operating parameters on the deacidification process: the initial free fatty acid content in oil (3.1, 5.8, 7.6 and 11.7% OA eq.), the ethanol-water content in solvent (70.0/30.0, 80.0/20.0, 87.8/12.2 and 95.6/4.4 g/g), and the oil/solvent ratio (0.50, 0.75 and 1.00 g/g). The economic assessment of the deacidification based on the costs of distilling solvent and neutral oil loss showed that the use of solvents containing 82 to 90 wt.% of ethanol enables to achieve a trade-off between efficiency of the extraction of free fatty acid and the neutral oil losses. A three-stage crosscurrent extraction using a solvent at 88.6 wt.% of ethanol (global solvent/oil ratio: 8.0 g/g) reduced the free fatty acid content from 5.8% OA eq. (in crude walnut oil) to 0.3–0.4% OA eq. with a loss of 4.0% of neutral oil mass. Regarding the extraction of phthalates, our results showed that the lower the water content in the hydroethanolic solvent, the more efficient the extraction of butyl benzyl phthalate (BBP). Moreover, extraction with ethanol has successfully reduced the BBP content below the current regulatory limit.

The sunflower crop provides an important honey flow for beekeepers. In France, beekeepers observed a decrease in honey yield from this crop these past years compared to the 1980s–1990s. They suspect the new cultivars to be less productive in nectar compared to the older ones, but no data is available to support this, and it is known that climate conditions have a strong impact on nectar secretion. This study aimed to explore the effect of abiotic environmental conditions on nectar secretion in sunflower, as well the range of variation of this secretion in a sample of current cultivars. Thirty-four current sunflower hybrid cultivars were sampled in test plots for their nectar secretion under varying conditions of temperature, air humidity and soil moisture. Air humidity controlled the sugar concentration of nectar, and thus its volume. To study nectar secretion independently from this effect, analyses subsequently focused on nectar sugar mass per floret. The nectar sugar mass increased with temperature up to an optimum of 32 °C, while the variation range of soil water tension was not sufficient to detect an effect on nectar sugar mass. This varied by up to 100% among the 34 cultivars (from 101 to 216 μg sugar per staminate floret in average), with a similar range to those reported in the literature for older cultivars. Likewise, oleic cultivars, a new type introduced since the early 2000s, were found to secrete the same amounts of nectar as linoleic cultivars, an older conventional type. The more self-fertile cultivars also showed no reduction in nectar secretion. Finally, we tested the method that measures the nectar gross secretion rate in one hybrid, and we observed that this hybrid secreted in average 28 μg sugar per hour per staminate floret. The potential benefits of this method were discussed.

This article describes how the transcriptomic data were produced on sunflower plants subjected to water deficit. Twenty-four sunflower (Helianthus annuus) genotypes were selected to represent genetic diversity within cultivated sunflower and included both inbred lines and their hybrids. Drought stress was applied to plants in pots at the vegetative stage using the high-throughput phenotyping platform Heliaphen. Here, we provide transcriptomic data from sunflower leaves. These data differentiate both plant water status and the different genotypes. They constitute a valuable resource to the community to study adaptation of crops to drought and the transcriptomic basis of heterosis.

In the extraction of vegetable oils, the idea of using ethanol as a solvent, allowing solvent recycling without distillation, can be attested as early as 1948 (Beckel), yet it is now seldom envisaged. The development of organic farming and a growing demand for a more natural diet prompted us to revisit this approach, which takes advantage of the relatively low affinity of ethanol for lipids to produce pure crude oils and meal with higher protein content. This method is based on the change of oil solubility in ethanol with temperature. Rapeseed oil extraction was carried out by hot pressurized ethanol (subcritical extraction condition). Oil was then recovered by cooling the miscella and demixing of two phases, an oil-rich phase and a solvent-rich phase. This study, after verifying the kinetics of extraction, focused on the optimization of the demixing temperature based on the amount and quality of recovered oil. The results show that ethanol extraction followed by cold demixing of the miscella makes it possible to obtain a high quality oil, free of free fatty acids and phospholipids.

A new extraction process using ethanol at a temperature above boiling point is assessed from an economic point of view. The study was based on an assessment of the main operating costs adjusted by Lang’s factor. Operating costs were assessed based on energy consumption calculated using a model of the process developed from experimental results, and for a hypothetical unit with a 160 000 t/year rapeseed crushing capacity. The processing cost was estimated at 47.4 € per ton of processed seed. Amortization represented 35% of this cost, energy 32% and manpower 10%. Uncertainty about investment is the main factor that could lead to significant error in this cost, but this uncertainty could be offset by an adjustment of the amortization duration, most of the equipment being durable. Profit generated by the process relies principally on a better valuation of the meal: higher value comes from higher protein content and quality on the market for GM-free high protein feedstuffs. Oil quality is also improved by a lower oleic acidity, low phospholipid content and pigment concentration. This gain was estimated at 2.5% of the crude oil value. Unlike the conventional hexane process, hot ethanol extraction produces molasses in small proportions. Molasses value was set at 70% of corn price. The process profitability appears sufficiently positive to justify further research to test the hypothesis underlying our model. The main uncertainty lies in the performance of the process in real conditions of counter-flow extraction and solvent regeneration.

This study investigated alternative solvents: ethanol and isopropanol, to replace hexane and enhance the quality and value of oil and meal. Rapeseed oil extraction was carried out using ethanol (92 wt.% or 96 wt.%), isopropanol (84 wt.% or 88 wt.%) or hexane (as reference). Results show that hydroalcoholic extraction increased meal protein content by 13% compared to hexane extraction, but without significant influence of alcohol and water content. However, increasing water content improved glucosinolate extractability. Isopropanol 84 wt.% eliminated most glucosinolates from the seeds, decreasing glucosinolate concentration by 49–73% compared to meals extracted by the other alcohols.

Objective: To study of the compositional breakdown of seed components between the integument and the germ and its variability according to genetic and environmental factors. Methods: The study used 19 rapeseed lots grown in two areas of contrasted agronomical potential harvested in 2011. Pure fractions of hulls and germs were mechanically separated by centrifuge impacts after freezing the seeds. Chemical composition of the whole seeds and the pure kernel and hull fractions was determined. The results were used to calculate the seed hull content. Results: Hull accounted for 18.2% of total seed content. Real oil content of the hulls (8.4% dry basis) was lower than in the literature. Hulls contained 2.9% of the oil, 11.2% of the proteins, 73% of the NDF; 80% of the ADF, 95% of the lignin and 6.0% of the glucosinolates of the whole seed. The percentage of hulls in total seed content shows low variability, although the oil and the protein content of the fractions were significantly affected by cultivar and to a lesser extent by geographic location of the crops. Conclusion: Completely dehulled seeds could result in a meal with 48.3% protein (dry basis) and low fiber content (10.8% NDF, 6.6% ADF, 0.5% ADL) but higher glucosinolate content (130% compared to defatted seeds).

Sunflower seed quality, in particular the characteristics of hullability and protein content, has a significant impact on the protein content of the resulting meal. Seeds dehulled before crushing produce a meal with a protein content of approximately 36%; without dehulling, the protein content is typically in the range of 27–29%. This study seeks to assess the effect of sunflower variety on hullability and protein content. Genetic effects were studied by means of seed samples obtained from a network of variety evaluation trials undertaken across the production area in France for sunflowers. For both characteristics, significant differences between cultivars were observed; as a consequence, the potential protein content of their dehulled meals also ranged widely (34–44%). Genetic selection, which provides substantial improvements in both oil content and fatty acid composition, should therefore be expected to enhance the quality of sunflower meal.

Cooking-pressing or extrusion-pressing processes applied to soybeans produce partially deoiled cake used for animal feeding. These two processes were studied and compared with a view to implementation in an industrial unit. The various factors of hydrothermal treatment for conditioning the beans were studied at different scales (batch from 2 kg to 100 kg, and continuous flow at 100 kg/h) and the results showed the need for moist cooking to effectively deactivate the antitrypsin factors (FAT) while maintaining protein solubility. The extrusion-pressing was more effective for deoiling cakes than cookingpressing (5.4 vs. 6.7%) but less robust for deactivation of FAT (6.5 vs. 3.8 TIU/mg). The techno-economical study was carried out to simulate the crushing costs and net margins of both processes in a plant capacity of 20 000 t / year. It showed that the costs of both methods were similar (about 33 €/t). Gross margins were evaluated between 18 and 84 € / t in three valuation assumptions based on market price of oil, the mode value of the meal and the residual oil, the level of premiums GMO traceability and transport. The cooking-pressing process can also be applied to sunflower and rapeseed and versatility is an advantage to ensure continuous operation of the crushing unit in case of supply difficulties in soybean.

Sunflower meal is an alternative source of proteins for feedstuff but its high fiber content reduces the nutritional value. Different dehulling processes can improve the protein content and the nutritional value of meal. Partially dehulled sunflower meals with 32% and 36% of proteins produced in different crushing plants in France had been compared to non-dehulled sunflower meal (29% of proteins). The total French feedstuff production was simulated with a model including prices of raw materials observed during 2010-2011 campaign. The interest prices of the different qualities of sunflower meal compared to soybean meal varied from 0.43, 0.50 to 0.70 for 29, 32 and 36% of proteins content respectively. The 36% protein sunflower meal seems very well adapted to laying hens and ducks diets where 29% type should be more adapted to meat cows, sows and rabbits who need less concentrated diets. The new market for the 36 % protein sunflower meal type could notably help to provide local sources of proteins for high quality poultry production.

Energy consumption in oil mills is a major item of costs and a sensitive point in the production of biofuels. To improve their performance, industrials can recover lowtemperature heat thanks to a new technology of heat exchangers suitable for treating granular solid materials. Information about the energy requirements of the rapeseed crushing being not readily available, the article gives a detailed assessment of consumption items (per ton of seed: 263 MJ for preparation operations and 284 MJ for solvent extraction). These exchangers used as pre-conditioners saves about 55 MJ.t−1 of heat by use of steam condensates. We could go further in use of these devices on the one hand to recover heat from press cake and meal, and secondly to use recovered energy to dry and warm up the seeds before pre-pressing. In this configuration, the energy savings could reach 38% of current needs.

Dans le contexte du développement de la culture du soja dans le Sud-Ouest de la France et à partir d’un diagnostic des filières de production de graines et des débouchés possibles, la mise en place d’une unité de trituration est envisagée dans cette région selon trois scénarios de taille d’usine et de localisation (3000 tonnes par an (t/an) dans le bassin Tarn-Aveyron, 15 000 t/an dans le Gers et 30 000 t/an dans la vallée de la Garonne). Le procédé retenu (aplatissage-cuisson-pression) permet la production de tourteau de valeur alimentaire proche du tourteau de soja déshuilé importé. Un modèle de calcul de la marge nette de trituration a simulé le fonctionnement et les résultats économiques de ces usines de 2007 à 2014. Pour les scénarios 3000, 15 000 et 30 000 t/an, les résultats obtenus montrent que l’augmentation de la taille de l’usine réduit très fortement le coût de trituration (respectivement 119,6 €/t, 44,9 €/t et 33,6 €/t) et que les coûts de transport sont logiquement impactés par la densité des bassins de production et de consommation. Le surplus économique créé s’élève respectivement à –72, 10 et –2 €/t en moyenne pour la période 2007–2014 et s’améliore notablement pour les cinq derniers trimestres (–25, 57 et 45 €/t). Le fonctionnement de la filière a été simulé selon les points de vue des différents acteurs économiques (céréalier, organisme stockeur, éleveur) pour évaluer le bénéfice retiré. Des perspectives sont indiquées pour la réduction des coûts et pour l’amélioration de la valeur des produits créée.

Dehulling sunflower seeds can increase meal protein content by up to 35–36%. However, high variability in seed quality constitutes an obstacle to optimizing the dehulling process. This study has sought to identify the parameters that influence the protein content of sunflower seeds and the ease with which they can be dehulled. Genetic, climatic and crop management effects were studied using seed samples taken from farmers’ fields in south-west France. Soil and climatic effects were revealed to be important for protein content and ease of dehulling (hullability). Some cultivars were found to be significantly more difficult to dehull than others. No relationship was observed between oil content and protein content expressed as a proportion of DDM (defatted dry matter), but there was a significant negative linear relationship between hullability and oil content. Due to the wide range of locations and agricultural practices encountered in the farmers’ fields, it was not possible to verify with confidence the influence of other interactions such as nitrogen fertilization and the potential fertility of the fields. This work nevertheless showed that locality and growing conditions affect the quality of sunflower seeds. This variability in quality could be measured by crushers in order to optimize the dehulling process and thereby produce a meal of consistent quality, with a guaranteed protein content.

Vegetable oils take a large part in industry for food and non-food applications. However the extraction process of oil from oilseeds includes a solvent extraction step using hexane. Despite its various advantages it presents numerous drawbacks; it is sourced from petroleum, it has a high flammability and it appears to be dangerous for health and environment (CMR2). This study presents a theoretical screening using COSMO-RS simulations of the relative solubility of vegetable oil constituents regarding several bio-based solvents as well as an experimental screening of the efficiency of these solvents. The aim is to correlate simulations and experiments and give a preliminary evaluation for the substitution of hexane by bio-based solvents for the extraction of vegetable oils. Differences between theory and practice have been noticed for several solvents such as terpenes that appeared to be good candidates in theory and that were in fact the solvents that gave the lowest extraction yield.

The recent success of dehulled sunflower meals on the French market encourages reconsideration of the possibility of applying dehulling techniques to rapeseed. Hulls account for 18−20% of rapeseed mass; they contain mostly fibres (72%, 78% and 99%, respectively of the seeds’ NDF, ADF and ADL). Complete removal of these hulls would result in a high (43%) protein meal with enhanced added value. However, the technical feasibility of producing such a meal is impeded by the relatively high oil content of the hull fraction. This article presents a model of mass balance that takes account both of the purity of the “hull” and “kernel” fractions and comparisons of gross margins between conventional processing and dehulling-based processing. The value of dehulled rapeseed meal is assessed against both a range of market scenarios and the composition and price of a selection of alternative feeds. The gross margin differential favours dehulling only in periods where proteins are expensive and oil relatively cheap, as at present. Reducing the oil content of the hulls affects considerably the profitability of dehulling whereas modification of the protein content has only a modest impact. An important unknown is the effect of antinutritional factors on the final price of dehulled meals. Management of the glucosinolates residues through processing might decrease their noxiousness though the information on this is scant. Since this lack of knowledge is an impediment to the implementation of dehulling technology, research and development investments should start by addressing this question. Technical solutions could be developed to recover the oil contained in the hulls. Such solutions include expelling, aqueous extraction or tail-end dehulling after direct extraction of the seeds.

Global rapeseed production has undergone sustained growth over the past 20 years. Having surpassed cottonseed production in the early 2000’s, it is now the second most produced oilseed behind soybeans. The major producers are China, India, Canada and European Union (27). During this same period, rapeseed crushing has risen strongly, Europe being the major player in this expansion (development of biodiesel) followed to a lesser extent by Canada and China. World exports of rapeseeds are dominated by Canada, by far the largest exporter. Japan is a traditional importer, while China and the EU (27) are less regular buyers. Although less spectacular than palm oil growth, rapeseed oil growth is also remarkable. Its consumption occurs mainly in the crushing countries, the EU being the principal consumer. Rapeseed meal is the second major oilseed meal produced worldwide (after soybean meal). It has been following broadly the same trends as seeds and oils, this evolution was marked a short period of stagnation in the early 2000’s. Consumption of rapeseed meal has grown strongly in the EU (which is deficient in protein feed), in China (due to its extraordinary economic development), and in the USA (due to milk producers’ demand for feed). The main exporters of rapeseed meals are Canada and India. Oilseed prices spiked in 2008 and since 2010 are remaining at historically high levels: whilst prices fell sharply following the 2013 harvest, they remain well above the lows of 2009. Rape seed meal, however, will remain a secondary meal with known drawbacks; there is little prospect of its price going higher than 65–70% of that of soybean meal.