Direct extraction of sunflower seed by filtration-extraction

Conclusions The influence of certain variables upon the direct, continuous, solvent extraction of sunflower seed meats has been discussed. It has been shown that the ideal preparation consisted of first reducing the hull content to about 10% by weight. Then the dehulled meats were rolled, cooked, crisped, and re-rolled prior to solvent extraction. Drying before rolling, followed by cooking and crisping, was also helpful in the reduction of residual lipids content but to a lesser degree than was re-rolling after cooking. It has been shown that the use of relatively low solvent/meats ratios required initially high mass velocities and that mass velocity during extraction was higher than that realized during cake washing. The full industrial-scale run confirmed the experimental findings; thus the direct, continuous, solvent extraction of sunflower seed meats is a commercial reality. An oil-content reduction from 53% to 1.68% in one operation is a technological advance of great magnitude. Except for periods when rice bran is processed, the plant is in continuous operation on sunflower seed meats and consistently produces meals containing between 1.5% and 1.7% oil content.     

Prepress solvent extraction of cuphea seed

Simulation of commercial processing of Cuphea seed to obtain needed quantities of oil and meal was accomplished with pilot facilities. Cuphea seed was conditioned in a single-deck cooker. Cooked seed was pressed with a mechanical screw with two-speed shaft, variable-speed drives and a four-section cage with cored sleeves. A feed rate of 22 kg seed/h and a feed screw-to-main shaft ratio of 2:1 gave good press cake with 8.1% residual oil. Press cake was extracted in a batch-type modular extraction pilot plant. Miscella stages were sequentially pumped through the beds, followed by hexane rinses. Spent cake was desolventized and toasted, and full miscellas were stripped to recover the crude oil. The finished Cuphea meal had only 0.30–0.55% residual oil. Thus, conditioned Cuphea seed was easily pressed without prior flaking to acceptable cakes, and conditions simulating commercial solvent extraction efficiently removed residual cake oil.     

Supercritical fluid extraction in sunflower seed technology

Sunflower (Helianthus annuus L.) seed represents an important source for edible oil and its protein fraction is also recognised as valuable for human consumption when suitably purified from polyphenols, which negatively affect colour and nutritional value. On this basis, a main research has been developed, with the aim of testing the technical feasibility of a supercritical fluid extraction (SFE) process involving a preliminary supercritical CO₂ (SC‐CO₂) extraction of oil from sunflower de‐hulled seeds, followed by the removal of polyphenols from de‐fatted meal by means of ethanol coupled with SC‐CO₂. The paper reports the experimental protocol followed, together with the kinetics of the extractions, knowledge of which allows the optimisation of working parameters and the determination of process yields.     

Continuous solvent extraction of soybeans and cottonseed

The current trend in soybean processing in the United States is toward ever larger capacities handled through single extractors and desolventizer-toasters. There are 20 such plants which average over 2,000 tons per day, with the largest handling over 3,000 tons per day. Slight differences in extraction efficiency, in heat economy, in solvent loss, and in plant reliability make or lose thousands of dollars each day for such plants. The operating characteristics of these 20 plants which now crush over half of all the U.S. soybean production are detailed. Cottonseed is the most complex and variable of all the oilseeds. A review of the corresponding variation in the processing conditions required to obtain quality products is made.     

Alcoholic extraction of vegetable oils. III. Solubilities of babassu,coconut, olive,palm, rapeseed,and sunflower seed oils in aqueous ethanol

Summary Solubilities of babassu, coconut, olive, palm, rapeseed, and sunflower seed oils in aqueous alcoholic solutions at various temperatures were determined by a direct and simple method. Solubility curves for the six oils are presented. The critical solution temperatures increase with the water content of the alcohol, and in each case the relationship is linear. The pressure in the system also varies with the temperature, the maximum being about 20 p.s.i.g.     

Drying,storage, and preparation of copra for extraction of oil

Various methods are used in drying copra. Because of costs, fuel oil and electricity are avoided by copra producers. Sun-drying remains as a cheap practical way of drying. Direct drying kilns rely on direct contact of combustion gases with coconut meat and produce a generally inferior grade of copra. Indirect drying kilns produce excellent copra. Various preparatory equipment may be used satisfactorily. A new copra oil mill will be most economically designed for handling copra as the main raw material. If, however, an existing oil mill is to diversify to include copra as new raw material, only minor equipment changes are needed. By 1980, copra will almost disappear as an export item, because the coconut producing countries will press and extract coconut oil domestically. The coconut-producing countries hope to obtain better quality of products, improve profit, and contribute to local economy by using local resources.     

Supercritical extraction of sunflower seed oil: Experimental data and model validation

In this work experimental results of sunflower seed oil extraction using supercritical CO₂ are presented, together with the outcome obtained by applying to the same data a theoretical model recently developed and further improved here.We performed extraction tests utilizing a supercritical extraction equipment having a volumetric capability of 100 ml; the seeds were milled to obtain different particle sizes (mean diameter between 0.19 and 1.2 mm); the range of pressure investigated was 280–550 bar, the temperature and solvent flow rate were maintained constant at about 40 °C and 10 g/min, respectively.The model accounts for the distinction between broken and intact oil-bearing cells and describes the extraction kinetics similar to the shrinking core models: it allowed satisfactory fitting of the experimental data and permitted to calculate the effective diffusivity of the oil in the seed, which resulted equal to 3 × 10⁻¹¹ m²/s. The reliability of the model is demonstrated by the fact that the value of the effective diffusivity, resulting from model optimization procedures, is similar for the various experimental tests.     

Pre-Pressing of oil from rapeseed and sunflower

The current methods of prepressing rapeseed and sunflower seed prior to solvent extraction are reviewed on a stage-by-stage basis. The energy consumption numbers are examined and the overall extractability of the presscake is discussed. Possible changes in processing methods, with advantages and drawbacks, are set out.     

Supercritical extraction of borage seed oil coupled to conventional solvent extraction of antioxidants

This paper describes the extraction of borage seed oil by supercritical carbon dioxide (SC-CO₂) and the further extraction of antioxidants from the SC-CO₂-defatted borage meal with organic solvents (water, methanol, ethanol and ethyl acetate). The optimal conditions for oil extraction were obtained at 303 and 323 K at 200 bar, 2.5 h and a continuous flow of CO₂ of 1.5 L/h introduced through the bottom when the operating pressure and temperature were reached, attaining a yield of 60%. Borage oil is rich in unsaturated fatty acids; oleic acid, linoleic acid and linolenic acid accounted for 74% of the total fatty acid content under the above conditions. The highest extraction yield was achieved using water or methanol as extracting solvent from the SC-CO₂-defatted borage meal at 303 K and pressures of 200 and 150 bar for water and methanol, respectively. The most potent extracts, according to all methods tested, were obtained with water and methanol.     

Evaluation of the diffusion coefficient of rapeseed oil during solvent extraction with hexane

The diffusion coefficient of rapeseed oil was determined from data obtained during time-varied solvent extraction experiments. The experiments were carried out in a Gülbaran extractor-diffuser with hexane as the solvent. A relationship was found between the slope of the diffusion line and the shape and size of the rapeseed particles. This relation can be used to calculate the diffusion coefficient. A diffusion coefficient of 3.4×10⁻⁸ cm²/s was determined from the experimental data.     

Evaluation of extractive contact units for oil extraction from dehulled sunflower seed

The efficiency of an extractive system generally depends on kinetic, thermodynamic and technological parameters. Each of these factors affects the extractive effectiveness, although the overall result depends on their interaction. In the present work this interaction is analyzed for oil extraction from dehulled sunflower seed. Experiments on laboratory scale were made to calculate the kinetic and thermodynamic parameters of the extraction. The behavior of the system in 2 typical contact units (mixer-settler and semicontinuous extractor) was studied and models assuming equilibrium conditions were formulated. The soundness of the models was checked by pilot-plant tests and good agreement was obtained as long as the residual oil concentration in the solid was higher than ca 0.01 c_so At lower oil concentrations the contact time becomes the main factor of the process, and the extraction is much less affected by the extraction ratio and the composition of the liquid.     

Supercritical fluid extraction of sunflower seed oil with CO2-ethanol mixtures

The effect of ethanol addition to supercritical carbon dioxide (SC-CO₂), up to 20%, on sunflower seed oil extraction over the range of 150 to 350 bars and 42 to 80°C was studied. A nonrecirculating home-made bench-scale system was used as extraction equipment. The oil-SC-CO₂-ethanol mixture was reduced to atmospheric pressure in a test tube, where two phases, oil and ethanol, were obtained and ethanol-saturated CO₂ was liberated to the atmosphere. Results show that sunflower oil solubility in SC-CO₂ greatly increases with addition of ethanol as entrainer over the whole range of pressure and temperature conditions. Some phospholipids are co-extracted at levels directly proportional to the added ethanol. Moreover, a large amount of phospholipids was recovered in the ethanolic phase. Acidity of the extracted oil with ethanol as entrainer was lower than that without alcohol. Part of the free fatty acids was found in the ethanolic phase.     

Effect of seed preparation on efficiency and oil quality in filtration extraction of rapeseed

The application of filtration extraction to rapeseed is discussed with particular emphasis on the effect of seed preparation on the hydrogenation characteristics of the oil. It was found that cooking the crushed seed without the addition of water, and at temperatures not exceeding 220F, produced a satisfactory oil. Under these conditions extraction efficiency was good and the resulting meal showed no harmful effects in feeding trials with mice. Presented at AOCS meeting in Toronto, 1962. N.R.C. 7667.     

超声强化提取薏苡仁油的研究

研究了提取溶剂、提取温度、料液比、薏苡仁粒径、提取时间对超声提取薏苡仁油的影响。在单因素实验的基础上 ,进行了正交实验。结果表明 ,各因素对油提取率的影响次序为 :物料粒径 >超声提取温度 >超声提取时间 >超声频率和功率 >料液比。优化后的工艺参数为 :提取温度 50℃ ,物料粒径 60～ 80目 ,料液比 1∶3 5 ,超声功率和频率 2 5kHz、30 0W ,提取时间40min。     

A kinetic study of phospholipid extraction by degumming process in sunflower seed oil

During the refining process of vegetable oils (degumming), phospholipids are eliminated by thermal treatment with water (hydratable phospholipids, HP) and other degumming agents such as phosphoric acid, citric acid, or acid mixtures (nonhydratable phospholipids, NHP). Samples of pressed crude sunflower oils were degummed with water and acids, and the corresponding pellets (gums) and supernatant oils were obtained by centrifugation. During the water degumming process, a decrease of more than 98% in the phosphatidylcholine (PC) content was achieved in 5 min; phosphatidylethanolamine (PE) was the most difficult compound to be removed. Phosphatidylserine, phosphatidic acid, and phosphatidylinositol (PI) presented an intermediate behavior. The optimal contact time for quantitative extraction of the most important HP (PC, PI, and PE) in crude sunflower oils was 35 min. For acid treatments, a rapid elimination of the residual levels of PC was registered (5 min); the optimal contact times for the quantitative removal of the NHP were 35 min for phosphoric acid und acid mixture, and 25 min for citric acid. Taking into account that PE was the most difficult component to be removed, its level could be used as a monitor to evaluate the efficiency of the degumming process.     

Photoinduced and thermal oxidation of rapeseed and sunflower oils

The aim of the present study was to compare oxidative stability of different sunflower and rapeseed oils. Ultra violet (UV) irradiation was used as an accelerator of the oil oxidation process. After UV irradiation, the formed volatile compounds were extracted by headspace solid‐phase microextraction HS‐SPME (DVB/CAR/PDMS fibre) and analysed by gas chromatography coupled with a flame ionization detector (GC/FID). At the same time, the same oil samples were thermally oxidized. The induction periods were determined on the basis of hexanal to 2‐trans‐nonenal ratio in the analysed samples. Finally, the obtained results were compared with induction period values obtained through the determination of peroxide and anisidine values, and from the Rancimat method, manostatic test and differential scanning calorimetry (DSC) method. The results obtained using the new method were well correlated with those achieved with the well‐established analytical techniques. The values of the induction period obtained after UV/HS‐SPME/GC/FID were up to three times higher than those from Rancimat, but the correlation between these two methods was on a very good level (correlation coefficient R>0.98). Similar correlation was also observed between these new methods and the DSC or manostatic test. In all cases, better results were obtained for rapeseed oils than sunflower oils.     

Droplet vaporization modeling of rapeseed and sunflower methyl esters

For numerical simulations of the combustion of liquid fuels, a thoroughly validated and verified quantitative model for droplet evaporation is necessary. In this work a simple single droplet infinite conductivity model is simulated for low pressure (0.1 MPa) and various temperatures (550–1050 K) using a chosen property rule (see Eq. (7)) and five convection correlations (C1, C2, C3, C4, and C5, see (Table 1) to obtain the temporal evolution of droplet diameter squared, droplet surface temperature and average evaporation rates of vegetable oil derived biofuels – rapeseed methyl ester (RME) and sunflower methyl ester (SME) – under near-quiescent conditions. The predictions are compared with the experimental and analytical results of Morin et al. [1]. The model uses an effective Reynolds number to conflate the effects of forced and natural convection. It is observed that the predicted temporal history of droplet diameter for RME droplet matches more closely with correlation C1 for T_amb ? 748 K and correlation C2 for T_amb ? 803 K at various ambient temperatures (i.e., from low to high evaporation rate). The correct droplet lifetime is predicted best by C1 for all temperatures. For average evaporation rates for SME, C1 best fits the experimental data. For the average evaporation rate of RME, the present model with C1 gives a better prediction than the theoretical, and corrected theoretical results of Morin et al. [1], and is observed to match closely with their experimental results. The present results using C2 are also found close to the experimental results for RME and SME. It is observed that the oxidation of RME/SME is similar to n-decane – a pure component fuel.     

Fractionation of sunflower seed proteins

Fractionation of sunflower seed salt-soluble proteins, which amount to nearly 80% of the total seed nitrogen, has been performed by a method we proposed in 1970 and which was confirmed by several others. Three varieties of seeds have been investigated: ‘Armavirec,’ ‘Peredovik’, and a pure strain. The occurrence of three groups of proteic fractions was confirmed. Their proportions, which fluctuate with varieties, are roughly: 20% for “light” (low molecular weight) albumins, 5–10% for “heavy albumins,” and 70–80% for globulins. The first group was isolated by Sephadex G-50 chromatography from the other two, which were separated by dialysis. A second chromatography of these three groups on Sephadex G-200 has been realized (with preliminarily calibrated columns for molecular weight evaluations). “Light” albumins appear as a rather homogeneous constituent with a molecular weight of 14,000 and an aminoacid composition showing high amounts of methionine, cystine, arginine and glutamine. “Heavy” albumins, which are still mixed with globulin fractions after dialysis, have a molecular weight of 48,000 and a very different aminoacid composition with a high level of lysine. Globulins are composed of at least four different fractions, two of which (M=12,000 and M=25,000) are presumably subunits of the other two and have significantly different aminoacid compositions.     

Projection and prospects for sunflower seed

Oil-type sunflower production may be expected to increase during this decade and strengthen the crop’s position as the second largest world source of vegetable oil. The development would intensify its already profound effect upon world trade in general and the vegetable oil industry in particular. The Soviet Union, producer of more than half of the world’s supply of sunflower oil, has greatly influenced the position of this commodity. Apparent increasing production there and in other countries, including the U.S., will influence the market position of all vegetable oils. Sunflower oil with its many desirable characteristics should find ready acceptance in world markets. Sunflower meal should be competitive with most vegetable proteins. Domestic sunflower production has been competitive with other farm crops in many areas. Requirements for successful production include the application of good management and the use of available information and materials. In most instances where production has not been satisfactory, poor management, which is somewhat typical in attempting to grow most new crops, has existed. A need also exists for further development of high yielding varieties, insect and disease control, improved harvesting procedures, control of field losses to birds and improved cultural practices. Good progress is being made in each of these categories.