Free Oil Yield Research Articles

Effects of the Roasting-Assisted Aqueous Ethanol Extraction of Peanut Oil on the Structure and Functional Properties of Dreg Proteins.

The effects of the roasting-assisted aqueous ethanol extraction of peanut oil on the structure and functional properties of dreg proteins were investigated to interpret the high free oil yield and provide a basis for the full utilization of peanut protein resources. The roasting-assisted aqueous ethanol extraction of peanut oil obtained a free oil yield of 97.74% and a protein retention rate of 75.80% in the dreg. The water-holding capacity of dreg proteins increased significantly, and the oil-holding capacity and surface hydrophobicity decreased significantly, reducing the binding ability with oil and thus facilitating the release of oil. Although the relative crystallinity and denaturation enthalpy of the dreg proteins decreased slightly, the denaturation temperatures remained unchanged. Infrared and Raman spectra identified decreases in the C-H stretching vibration, Fermi resonance and α-helix, and increases in random coil, β-sheet and β-turn, showing a slight decrease in the overall ordering of proteins. After the roasting treatment, 62.57-135.33% of the protein functional properties were still preserved. Therefore, the roasting-assisted aqueous ethanol extraction of peanut oil is beneficial for fully utilizing the oil and protein resources in peanuts.

Demulsification of Emulsion Using Heptanoic Acid during Aqueous Enzymatic Extraction and the Characterization of Peanut Oil and Proteins Extracted.

Peanut oil body emulsion occurs during the process of aqueous enzymatic extraction (AEE). The free oil is difficult to release and extract because its structure is stable and not easily destroyed. Demulsification can release free oil in an oil body emulsion, so various fatty acids were selected for the demulsification. Changes in the amount of heptanoic acid added, solid-liquid ratio, reaction temperature, and reaction time were adopted to investigate demulsification, and the technological conditions of demulsification were optimized. While the optimal conditions were the addition of 1.26% of heptanoic acid, solid-liquid ratio of 1:3.25, reaction temperature of 72.7 °C, and reaction time of 55 min, the maximum free oil yield was (95.84 ± 0.19)%. The analysis of the fatty acid composition and physicochemical characterization of peanut oils extracted using four methods were studied during the AEE process. Compared with the amount of oil extracted via other methods, the unsaturated fatty acids of oils extracted from demulsification with heptanoic acid contained 78.81%, which was significantly higher than the other three methods. The results of physicochemical characterization indicated that the oil obtained by demulsification with heptanoic acid had a higher quality. According to the analysis of the amino acid composition, the protein obtained using AEE was similar to that of commercial peanut protein powder (CPPP). However, the essential amino acid content of proteins extracted via AEE was significantly higher than that of CPPP. The capacity of water (oil) holding, emulsifying activity, and foaming properties of protein obtained via AEE were better than those for CPPP. Overall, heptanoic acid demulsification is a potential demulsification method, thus, this work provides a new idea for the industrial application of simultaneous separation of oil and proteins via AEE.

Demulsification of peanut emulsion by aqueous enzymatic extraction using a combination of oleic and citric acids

In the present study, the effect of demulsification of peanut emulsion using a combination of oleic and citric acids mechanism was investigated. The free oil yield was 95.87% under optimal conditions. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed that the protein composition of the emulsion treated with citric acid and oleic acid was similar to that of the sample emulsion. Citric acid increased the particle size and ζ-potential of the emulsion. When the content of oleic acid reached 1.5%, the conductivity of the emulsion significantly decreased and Fourier-transform infrared spectroscopy demonstrated that the intensity of the hydroxyl absorption peak decreased significantly. Gas chromatography analysis revealed that the content of free oil oleic acid increased by only 0.4–0.5%. The phase transformation process during demulsification was investigated by optical and confocal laser scanning microscopy. Oleic acid combined with phospholipids changed the surface hydrophilic–lipophilic balance, and the emulsion changed from oil-in-water to water-in-oil. Small-Angle X-ray scattering analysis deduced that the droplets in the demulsified emulsion were approximately spherical reverse micelles. Results from this study suggest that improvement of combination of oleic and citric acids technology to is important for the large-scale industrial application of an aqueous enzymatic method.

Assessment of obtaining sunflower oil from enzymatic aqueous extraction using protease enzymes

The aim of this work was to maximize the enzymatic aqueous extraction (EAE) of sunflower seed oil using protease enzymes from the evaluation of various temperatures, pH and enzyme concentrations, using a Box-Behnken experimental design. The effect of a thermal pre-treatment of sunflower seeds on free oil yield (FOY) and oil quality was also determined. In the experimental range adopted, a lower temperature (40 °C) provided higher FOY values, as well as the intermediate pH (8.00) and maximum enzyme concentration (9% v/v). Thermal pre-treatment provided an increase in FOY in the initial extraction times (60 to 180 min) and decreased of the extraction time of 4 to 3 h to obtain the highest FOY value (~16%). The fatty acid composition of the oils obtained showed a predominance of oleic (~47.5%) and linoleic acids (~39.5%). The total phytosterol content in the samples was hardly affected by the heat pre-treatment of the seeds, while the fatty acid profile, tocopherol content and oxidative stability were not altered.

Effect of Papain on the Demulsification of Peanut Oil Body Emulsion and the Corresponding Mechanism.

This study investigated the effect of papain on the demulsification of peanut oil body emulsion extracted using an aqueous enzymatic method and the associated mechanism. The highest free oil yield using papain (92.39%) was obtained under the following conditions: an enzymatic hydrolysis temperature of 55°C, sample-to-water ratio of 1:3, enzyme concentration of 1400 U/g, and an enzymatic hydrolysis time of 3 h. Papain degraded the peanut oil body protein to small-molecular-weight peptides (≤ 14.4 kDa). Compared to the emulsion before enzymatic hydrolysis, the amino acid content in the aqueous phase was higher after enzymatic hydrolysis, the viscosity of the oil body emulsion was lower, and the particle diameter of the emulsion was significantly larger. The following demulsification mechanism was derived. Papain degrades the protein on the peanut oil body and dissolves it in water. The outer side of the oil body loses the protection of electrostatic repulsion and steric hindrance provided by the membrane protein. This causes the viscosity of the emulsion system and the molecular steric hindrance to decrease. As a result, the oil droplets gather and eventually demulsify. The results of this study provide the theoretical basis for the instability in oil body emulsions and are expected to promote the application of enzymatic demulsification in industry.

Rapid Salt‐Assisted Microwave Demulsification of Oil‐Rich Emulsion Obtained by Aqueous Enzymatic Extraction of Peanut Seeds

AbstractAqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process that can also provide edible protein. However, the AEE process may form a stable emulsion in most cases, which seriously limits the large‐scale industry applications for producing vegetable oils. In this study, the salt‐assisted microwave radiation demulsification of the oil‐rich emulsion prepared with AEE from peanuts is investigated. The microwave demulsification method is compared with other conventional demulsification methods, including heating, and freezing–thawing. The salt‐assisted microwave demulsification of the emulsions shows a greater free oil yield than conventional heating demulsification. Moreover, the microwave demulsification shows a similar free oil yield in less time than freezing–thawing method. Under the optimal operating conditions of demulsification, the free oil yield can reach 92.3% with CaCl2‐assisted microwave demulsification for only 2 min. In addition, the oxidative properties and the fatty acid compositions of the demulsified peanut oil are investigated. No significant difference in the fatty acid composition is observed among salt‐assisted microwave, freezing–thawing, and heating demulsified oil. The oxidative properties of the salt‐assisted microwave demulsified peanut oil is better than the conventional heating demulsified oil. Thus, salt‐assisted microwave demulsification provides a quick and effective demulsification method to obtain vegetable oils with high quality.Practical Applications: Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process. To solve the problem of stable emulsion formed during AEE process, the salt‐assisted microwave demulsification of the oil‐rich emulsion prepared with AEE is developed with high efficiency (demulsification for 2 min). In addition, the oxidative properties of the microwave demulsified oil is better than the conventional heating demulsified oil.

Sunflower oil from enzymatic aqueous extraction process: Maximization of free oil yield and oil characterization

AbstractIn this article, the enzymatic aqueous extraction (EAE) of sunflower seed oil was investigated. The effects of the operational variables (temperature, water seed mass ratio, and enzyme concentration) were evaluated in order to define the conditions that maximize the free oil yield (FOY). It was observed that increasing the amounts of water and enzyme in the extraction medium was disadvantageous to the removal of the oil, and that an increase in temperature provided a higher FOY. Thus, a temperature of 60°C, seed:water ratio of 1:5 (g/g), and enzyme concentration of 1% (v/v) were defined as the conditions for maximum FOY (17.76%). The use of a buffered medium under these conditions increased the FOY to 20.34%. The composition of the oils obtained by the EAE under different experimental conditions was determined and compared with the oil obtained from Soxhlet extraction. The oils under study presented high levels of oleic and linoleic acids, which corresponded to ~90% of the composition of fatty acids. It was also noted that, depending on the extraction conditions, the oils obtained by EAE presented phytosterol and tocopherol contents similar or superior to those of the oil produced by Soxhlet extraction.Practical ApplicationsThe enzymatic aqueous extraction of sunflower oil has the potential to replace the solvent extraction method. The results reported herein show that the composition of the sunflower oil obtained by the enzymatic method was similar to that of the oil extracted by the solvent method. In addition, the enzymatic method uses mild conditions that reduce the energy required for the process and the residues are free of organic solvent.

Economic Feasibility of Soybean Oil Production by Enzyme-Assisted Aqueous Extraction Processing

Aqueous oil extraction is an approach that could replace organic solvent extraction with water. Compared to typical solvent extraction and mechanical pressing processes, aqueous extraction has higher oil recovery (over 80%) than the mechanical pressing process, and resolve issues resulted from chemical loading and remaining in the hexane extraction. Proteases are used to assist free oil release from oil bodies by hydrolyzing cotyledon cell walls in aqueous extraction process. The resulting enzyme-assisted aqueous extraction process (EAEP) includes dehulling, flaking, extruding, enzymatic extraction, and enzymatic demulsification processes. SuperPro Designer was used to conduct a techno-economic analysis (TEA) of the extraction process. The total capital investment, operation cost, and profits were evaluated. During EAEP, insolubility of water and oil allows the simultaneous extraction of protein and oil. This decreases operation costs, especially the oil purification process, and therefore increases profits made from the main product (soybean oil). This simultaneous extraction also increases the profit towards the coproduct, i.e., protein in skim. Additionally, the absence of chemical and enzyme recycling contribute to the better economic value of EAEP. Despite the increase in facility costs due to extraction and demulsification units, the value-added coproduct extraction and high free oil yield contribute to the economic feasibility of EAEP in industrial- and commercial-scale productions when skim and insoluble fiber are used as water and carbohydrate supplies for integrated soy/corn ethanol biorefinery processing.

Geochemical property modelling of a potential shale reservoir in the Canning Basin (Western Australia), using Artificial Neural Networks and geostatistical tools

In underexplored sedimentary basins, understanding of the geochemical property distribution is paramount to a successful exploration campaign. This is traditionally obtained through the routine laboratory pyrolysis experiments. Compared to Machine Learning approaches, bulk geochemical analysis is relatively more time consuming, more expensive and generally provides property distribution in a lower resolution. This study has used the Artificial Neural Networks approach to predict continuous geochemical logs in wells with no or limited geochemical information. The neural network was trained with the Levenberg-Marquardt training algorithm, based on the established relationships between the typical well logs with laboratory measured geochemical data. A total of 96 data points from the Goldwyer shale of the Canning Basin, WA were used to train the network, with an accuracy of greater than 75% R2 values for the training, test and validation data in all models. The predicted, continuous geochemical logs have a good agreement with the laboratory measured geochemical data, particularly the TOC and S2 logs. Subsequently, these optimised geochemical logs are used as the input into a petrophysical property model to predict the organic matter distribution across the Broome Platform of the Canning Basin. This revealed the potential geochemical sweet spots, with higher free oil yield (S1), source rock potential (S2) and organic content (TOC) towards the north-western part of the sub-basin. The kerogen type distribution, on the other hand shows that in the south-eastern part of the sub basin, the shales yield Type II to Type III kerogen type, while they are predominantly Type III in the north-western part of the study area.

Process Optimization for Extraction of Millet Small Bran Oil by Aqueous Ethanol

Millet small bran is a kind of byproduct of the millet processing. It is a cost-effective resource for healthy nutritious oil, which contains 23% oil, with 72% essential fatty acid, tocopherol, phytosterol and oryzanol. In recent years, aqueous enzymatic extraction of millet bran oil has been researched widely. However, this method has the disadvantages of high production costs, low extraction efficiency and great loss of nutrition. In order to reduce the production cost and improve nutritive value of the products, the ethanol extraction method was developed and response surface method (RSM) was used to optimize extraction conditions. The research investigated the influence of extraction temperature, extraction time, solid-liquid ratio and ethanol concentration. The result showed that extraction time, solid-liquid ratio and ethanol concentration made the most contribution to enhancing free oil yield. According to the principle of box–behnken design, response surface analysis of 3 factors and 3 levels was used to optimize the extraction process. The optimal conditions of this aqueous extraction method were: extraction time (120min), solid-liquid ratio (1:5) and ethanol concentration (30%). Under the optimal conditions, the oil yield reached 89.216%. Through determining the quality indices such as acidity, peroxide value and water content of millet small bran oil extracted by aqueous ethanol solution, it could be concluded that the quality of extracted oil was superior to the national standard of crude millet bran oil and similar to the first grade pressed bran oil under the national standard. The contents of tocopherol and phospholipid in millet small bran oil were 131.32mg/100g and 1.12g/100g, respectively. Aqueous ethanol extraction method is not only an efficient and suitable method of extracting millet small bran oil, but also preserve the nutrients like phospholipid and tocopherol to the greatest extent. Hence, it can be concluded that aqueous ethanol technology has a good applying prospect in oil production industry.

Secondary structure of proteins on oil release in aqueous enzymatic extraction of rapeseed oil as affected hydrolysis state

ABSTRACTIn this study, the relationship between protein hydrolysis and oil release was studied by fluorescence microscopy and Fourier Transform Infrared (FTIR) spectroscopy, respectively. Five commercial proteases (Flavourzyme 1000L, Neutrase 1.5MG, Protamex, Alcalase 2.4L, and Thermolysin) were evaluated for oil extraction from rapeseed, and Alcalase 2.4L was found to be the best enzyme for highest free oil yield (81.81%). When use this enzyme, the results showed that parts of proteins restricted the release of oil, and the oil released almost completely was achieved after hydrolysis for 3.0 h. To further reveal the relationship between oil release and protein hydrolysis, the effects of hydrolysis time on the degree of hydrolysis of protein, and free oil yield were studied. The results showed that the release of oil was only related to the hydrolysis of parts of proteins, and when the degree of hydrolysis of protein was more than 17.05%, the effect of protein hydrolysis on oil release was greatly reduced. The intrinsic relationship between the structural changes of proteins and the release of oil in the hydrolysis process was analyzed by comparing protein secondary structure of different hydrolysis time, and the results showed that the transition of protein structure from order to disorder was an important factor for oil release.

Efficient and Response Surface Optimized Aqueous Enzymatic Extraction of Camellia oleifera (Tea Seed) Oil Facilitated by Concurrent Calcium Chloride Addition

AbstractThis paper reports an efficient aqueous enzymatic extraction (AEE) method for Camellia oleifera seed oil with the aid of response surface analysis. A maximum oil recovery of ~93.5% was obtained when a 2‐step AEE process was performed using 0.80% cellulase (v/w) solution at pH 6.0 maintained at 50 °C for 1 h followed by a solution of 0.70% Alcalase® with pH 9.2 at 57 °C for 4.1 h. It was found that the addition of Ca2+ during the proteolysis stage improved the free oil yield from ~62.1 to ~86.6%. This was attributed to the removal of tea saponins, cross‐linkage of anionic polysaccharides, and destabilization of cream emulsion by Ca2+. This was verified by decreased tea saponin and polysaccharide levels in the cream emulsion and bulk solution as well as lowering of the emulsion fraction. It was determined that addition of CaCl2 solution in continuous flow to the proteolysate is superior to one‐time or batch addition in inhibiting emulsion formation. The addition of CaCl2 may provide a means of replacing the more laborious, time‐consuming demulsification process otherwise required.

Destabilization of Emulsion Formed During Aqueous Extraction of Peanut Oil: Synergistic Effect of Tween 20 and pH

AbstractTo destabilize the emulsion formed during aqueous extraction processing (AEP) of peanuts, Tween and Span series surfactants (Tween 20, Tween 80, Span 20, and Span 80) were used alone or in combination to break the emulsion. Results indicate that only Tween surfactants had a pronounced demulsifying effect that was dependent on Tween concentration and system pH. When 1.2 wt% Tween 20 aqueous solution was used for oil extraction at pH 10.0, the highest free oil yield was achieved at 76.1 %, which was similar to the oil recovery of using proteases as a destabilization agent. The results obtained using a model emulsion system containing peanut oil and Tween 20/peanut protein isolates (PPI) showed that when Tween 20 and PPI coexisted in extraction medium at pH 10.0, the dynamic interfacial tension and droplet size distribution curves were very similar to those when Tween 20 was used alone, suggesting that Tween 20 dominated at the interface, instead of PPI. Destabilization of the model emulsions relied on three important factors: inclusion of Tween 20 at the initial mixing stage, high pH, and a gentle mixing speed. A synergistic destabilization mechanism of using Tween 20 at high pH during AEP was proposed. The discovery of Tween 20 as an effective demulsifier significantly contributes to the development of AEP of oilseeds.

Effects of roasting temperatures and grinding type on the yields of oil and protein obtained by aqueous extraction processing

A three cylindrical roll crusher was used in this study to solve the comminution problem and to improve oil and protein yields in aqueous extraction processing (AEP) of peanuts. We combined confocal laser scanning microscopy (CLSM) and particle size distribution analysis to investigate the effect of different peanut processing material on oil and protein extraction. A proper roasting treatment (150 °C) is beneficial to oil extraction yield. However, the protein yield has been declining from 84.33% to 51.40% with the increase of roasting temperature from (130 °C–210 °C). The optimal average particle size of peanut paste in AEP was 15.2 μm which could hardly find intact oil bodies by CLMS. Nevertheless, the remained intact of protein body still could be found in insoluble fraction. In AEP, highest free oil yield (92.2%) was achieved with roasted peanut (150 °C, 20 min) using 1: 5 solid to liquid ratio (twice ground peanut pastes/water), pH 9, 60 °C for 2 h and demusification by adding 0.5% (w/w) Protex 50FP at pH 4.5 and incubating at 50 °C for 2 h. Without roasting treatment, the oil contents of insoluble and residual cream fractions from AEP were highly correlated with their protein contents (R2 = 0.8724, 0.9178, respectively). Additionally, the exposure of interior hydrophobic groups of peanut protein adhere more oil to the protein body surface, which may have led to increment in the oil content of insoluble fraction.

Aqueous enzymatic extraction and demulsification of camellia seed oil (Camellia oleifera Abel.) and the oil's physicochemical properties

An aqueous enzymatic extraction method was developed to extract oil from camellia seed (Camellia oleifera Abel.). Individual enzymes and combinations of enzymes, pH, the ratio of material to water, reaction time and methods of demulsification were studied. The effects of hexane and aqueous enzymatic extraction on the oil's physicochemical properties (acid value, peroxide value, fatty acid profile, phenolics, and phospholipids content) were compared. The combination of protease/cellulase yielded significantly more oil than did other combinations. Under the optimal reaction conditions, a free oil yield of 82.37% was obtained. Four types of demulsification methods were compared. After demulsification with 20% ethanol (v/v), the highest total free oil yield of 91.38% was achieved. Compared with hexane‐extracted oil, aqueous enzymatic‐extracted oil was more acidic; had a higher percentage of monounsaturated fatty acid and contents of vitamin E and squalene; and had lower peroxide values, percentage of total saturated fatty acid, polyunsaturated acid, and content of both total phenolics and total phospholipids.Practical applications: The current work will contribute to an efficient enzymatic extraction method for camellia seed oil and help with the develop a method to demulsify the emulsion.An aqueous enzymatic extraction method was developed to extract oil from camellia seed (Camellia oleifera Abel.). Individual enzymes and combinations of enzymes, pH, the ratio of material to water, reaction time and methods of demulsification were studied. The effects of hexane and aqueous enzymatic extraction on the oil's physicochemical properties (acid value, peroxide value, fatty acid profile, phenolics, and phospholipids content) were compared. The combination of protease/cellulase yielded significantly more oil than did other combinations. Under the optimal reaction conditions, a free oil yield of 82.37% was obtained. Four types of demulsification methods were compared. After demulsification with 20% ethanol (v/v), the highest total free oil yield of 91.38% was achieved. Compared with hexane‐extracted oil, aqueous enzymatic‐extracted oil was more acidic; had a higher percentage of monounsaturated fatty acid and contents of vitamin E and squalene; and had lower peroxide values, percentage of total saturated fatty acid, polyunsaturated acid, and content of both total phenolics and total phospholipids.

Optimization of Ethanol‐Ultrasound‐Assisted Destabilization of a Cream Recovered from Enzymatic Extraction of Soybean Oil

AbstractA novel method using ethanol and ultrasound to extract oil from cream obtained from enzyme‐assisted aqueous extraction of soybean oil was developed. To evaluate the relationships between operating variables and free oil yield and to maximize the free oil yield, response surface methodology was introduced in this work. The developed regression model was fitted with R2 = 0.9591. Optimized variables were: ethanol concentration of 73 %, ethanol addition volume of 0.55 L/kg, ultrasound power of 427 W, ultrasound time of 47 s, and ultrasound temperature of 53 °C. The free oil yield from the cream under the above conditions was 92.6 ± 3.4 %. Scanning electron microscopy (SEM) was used to evaluate the effect of ultrasonic treatment on ethanol‐treated cream, and the SEM images clearly showed that the ultrasound treatment affected dispersing and fracturing of the microstructure of ethanol‐treated cream.

Enzymatic Demulsification of the Oil‐Rich Emulsion Obtained by Aqueous Extraction of Peanut Seeds

AbstractThis study details the enzymatic destabilization of the emulsion formed during aqueous extraction of peanut seeds and the quality of the resulting oil. The emulsion was exposed to enzymatic treatment and pH adjustment. The experimental results suggest that the alkaline endopeptidase Mifong®2709 was the most effective demulsifier, while Phospholipase A2 and pH adjustment had little effect on emulsion stability. The demulsifying conditions of Mifong®2709 were optimized by response surface methodology (RSM). The optimal conditions which produced a free oil yield of ~94 % were: 1:1 water‐to‐emulsion ratio, enzyme concentration of 1,600 IU/g of emulsion and 70 min hydrolysis time at 50 °C. We found that these conditions resulted in a positive relationship (R2= 0.9671) between free oil yield and the degree of protein hydrolysis. Increased protease treatment produced a smaller number of oil droplets, but the size of these droplets increased significantly. When compared to demulsified oil products obtained by using thermal treatment, the oil obtained by Mifong®2709 exhibited lower acid and peroxide values, contained more tocopherols and had a longer induction time as determined in the Rancimat test. The high yield and quality of peanut oil obtained by enzymatic treatment makes enzyme demulsification a promising approach to recovering free oil in aqueous extractions of peanuts.

The Research on Freeze-Thaw De-Emulsification Technology in Enzyme-Assisted Aqueous Extraction Processing

Experiments were carried out to analysis optimization of freeze-thaw regression model with Response Surface Analysis Method. The optimal response result is: freeze temperature: -18°C, freeze time: 12.5h, thaw temperature: 57°C, released oil yield: 93.16%, total free oil yield rate: 89.28%. The mechanism of demulsification was studied using Micro-imaging, SEM cooling stage, DSC, FTIR spectrometer. DSSP was changed and part of hydrogen bond was broken and α－helix structure conversed to random coil during the freeze process were found the effective freeze-thaw method to destabilize the emulsion.

Modification of aqueous enzymatic oil extraction to increase the yield of corn oil from dry fractionated corn germ

In previous aqueous enzymatic oil extraction (AEOE) experiments we reported a best free oil yield of 49% of the hexane extracted yield of dry fractionated corn germ. In the current experiments, a dispersion of 10% cooked, dry-fractionated germ in water was treated with α-amylase, glucoamylase and a cellulase complex. Free oil was collected by centrifuging a foam fraction of the dispersion. Several dispersion treatments were tried to evaluate their release of free oil and effect on the production of foam. The foam contained up to 8% free oil (dispersed from germ containing 26% oil) and fines oil (not centrifugally separable), protein and germ particles. Treatment with α-amylase and glucoamylase prior to treatment with the commercial cellulase used in previous AEOE studies increased the free oil yields about 25–61% of the hexane-extractable yield. A preliminary cost analysis indicates that oil separation with the amylase enhanced AEOE appears to be preferable to AEOE alone and profitable if crude corn oil cost exceeds $1.1/kg ($0.50/lb).

Advances in Aqueous Extraction Processing of Soybeans

AbstractAqueous extraction processing technologies, having advanced in recent years, may be a viable alternative to hexane extraction to separate oil and protein from soybeans. Different extraction strategies incorporating various modes of comminution, extraction buffers, and enzymes allow production of a range of oil and protein products, but also create different processing challenges. Processes capable of achieving high free oil yields often result in a soluble protein fraction difficult to isolate and dilute oil emulsions difficult to break. Other processes can achieve high yields and purities of native soy protein, but with reduced free oil yield or require a high osmotic and ionic strength extraction buffer. This review article discusses these various advanced processes and their relative advantages and disadvantages. In addition, the current understanding of the underlying fundamental concepts of aqueous extraction is discussed in order to help direct future investigations to improve these technologies.