An energy-friendly alternative in the large-scale production of soybean oil.

Soybean oil is widely used as cooking oil, whereas the soybean cake is a valuable ingredient for animal food. The extraction of soybean oil is an energy-intensive process, with additional significant impact on the environment via the wastewater and hexane emissions. The research investigated different ways to minimize the energy consumption. In a traditional process, both direct (live) steam and indirect steam heating (jackets, tubular exchangers) are used to deliver the required heat duty. Direct steam injection is restricted to the first evaporator and the stripper, for a total of 620 kg/h. Indirect steam is also applied in the evaporators for a total of 6.44 MW. The desolventizing process requires a steam energy input of 8.15 MW. Integration of a heat exchanger network in the evaporation and stripping part of the process reduces the amount of direct steam usage from 620 kg/h to 270 kg/h and of the indirect heat duty from 6.44 to 5.05 MW. In the cake desolventizing part of the process, the energy requirement is reduced from 8.15 to 2.12 MW. The overall gross energy saving is hence ∼50%. The improvements moreover reduce both the waste water loadings by 56.5% and the CO2 emissions by 62.5%. Hexane emissions are moreover significantly (>90%) reduced.

Tracking Changes of Hexabromocyclododecanes during the Refining Process in Peanut, Corn, and Soybean Oils.

Hexabromocyclododecanes (HBCDs) are harmful compounds, which could be taken up by plants and occur in vegetable oils. In this study, we systematically tracked the changes of HBCDs during different refining processes in peanut, corn, and soybean oils in China. The refining processes were efficient at removing the concentrations of total HBCDs (∑HBCDs), although the levels did increase for peanut and corn oils during the neutralization and bleaching steps. Quite significant reductions in the ∑HBCD concentrations were observed for soybean oils (71-100%) through refining. α-HBCD and ∑HBCD levels were significantly and positively correlated with the peroxidation value (PV), suggesting that PV might be an indicator reflecting the changes of α-HBCD and ∑HBCDs during the oil-refining processes. HBCD intakes from vegetable oils represented a low concern for public health. The results might be helpful for quality and process control with a view to minimize the levels of HBCDs in vegetable oils.

Enzyme-based processing of soybean carbohydrate: Recent developments and future prospects.

Soybean is well known for its high-value oil and protein. Carbohydrate is, however, an underutilized major component, representing almost 26-30% (w/w) of the dried bean. The complex soybean carbohydrate is not easily hydrolyzable and can cause indigestibility when included in food and feed. Enzymes can be used to hydrolyze the carbohydrate for improving soybean processing and value of soybean products. Here the enzyme-based processing developed for the following purposes is reviewed: hydrolysis of different carbohydrate-rich by/products from soybean processing, improvement of soybean oil extraction, and increase of nutritional value of soybean-based food and animal feed. Once hydrolyzed into fermentable sugars, soybean carbohydrate can find more value-added applications and further improve the overall economics of soybean processing.

Regeneration of Waste Edible Oil by the Use of Virgin and Calcined Magnesium Hydroxide as Adsorbents.

In this study, we prepared virgin (S, L) and calcined (S-380, S-1000, L-380, L-1000) magnesium hydroxide for regeneration of waste edible oil. Deterioration of soybean oil, rapeseed oil, and olive oil was achieved by heat and aeration treatment. The properties of the different adsorbents were investigated using specific surface area measurements, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric-differential thermal analysis, and surface pH measurement. Moreover, the relationship between the changes in acid value (AV) and carbonyl value (CV) and the adsorbent properties were evaluated. The specific surface areas of S-380 and L-380 were greater than that of other adsorbents. In addition, the XRD results show that S-380 and L-380 contain both magnesium hydroxide and magnesium oxide structures. The decreases in AV and CV using S-380 and L-380 were greater than achieved using other adsorbents. The correlation coefficients between the decrease in AV and CV and specific surface area were 0.947 for soybean oil, 0.649 for rapeseed oil, and 0.773 for olive oil, respectively. The results obtained in this study suggest that a physical property of the adsorbent, namely specific surface area, was primarily responsible for the observed decreases in AV and CV. Overall, the results suggest that S-380 and L-380 are useful for the regeneration of waste edible oil.

Water reclamation from emulsified oily wastewater via effective forward osmosis hollow fiber membranes under the PRO mode.

By using a novel hydrophilic cellulose acetate butyrate (CAB) as the membrane material for the hollow fiber substrate and modifying its outer surface by polydopamine (PDA) coating and inner surface by interfacial polymerization, we have demonstrated that the thin-film composite (TFC) membranes can be effectively used for sustainable water reclamation from emulsified oil/water streams via forward osmosis (FO) under the pressure retarded osmosis (PRO) mode. The newly developed TFC-FO hollow fiber membrane shows characteristics of high water flux, outstanding salt and oil rejection, and low fouling propensity. Under the PRO mode, the newly developed TFC-FO membrane exhibits a water flux of 37.1 L m(-2) h(-1) with an oil rejection of 99.9% using a 2000 ppm soybean oil/water emulsion as the feed and 1 M NaCl as the draw solution. Remarkable anti-fouling behaviors have also been observed. Under the PRO mode, the water flux decline is only 10% of the initial value even after a 12 h test for oil/water separation. The water flux of the fouled membrane can be effectively restored to 97% of the original value by water rinses on the fiber outer surface without using any chemicals. Furthermore, the flux declines are only 25% and 52% when the water recovery of a 2000 ppm soybean oil/water emulsion and a 2000 ppm petroleum oil/water emulsion containing 0.04 M NaCl reaches 82%, respectively. This study may not only provide insightful guidelines for the fabrication of effective TFC-FO membranes with high performance and low fouling behaviors for oily wastewater under the PRO mode but also add an alternative perspective to the design of new materials for water purification purposes.

The evaluation and comparison of consecutive high speed centrifugation and LipoClear® reagent for lipemia removal.

BACKGROUND: The aim of this study was to evaluate and compare the efficiency of high speed centrifugation and LipoClear® reagent for lipemia removal in plasma samples spiked with Intralipid®, for 26 biochemistry analytes. MATERIALS AND METHODS: A plasma pool was collected. Aliquots of the pool were spiked with Intralipid® (final concentrations of 300mg/dL and 500mg/dL Intralipid®). The lipemia was removed from the aliquots by high speed centrifugation or LipoClear® reagent. 26 analytes were determined in native, lipemic plasma and in samples after lipemia removal. The bias from the concentration in the native sample was calculated for each parameter for Intralipid® concentrations, 300 and 500mg/dL of Intralipid®, respectively. Also, the recovery for each parameter after processing the samples using high speed centrifugation and LipoClear® was calculated. The biases and test recoveries were compared with the desirable specification for imprecision (DSI) according to Ricos available at the Wesgard's website. The bias and recovery for procalcitonin were compared with DSI according to Barassi and colleagues. RESULTS: The bias of the spiked samples exceeded the DSI at 300mg/L Intralipid® for creatinine, glucose, total protein, iron and albumin; and for all previously mentioned parameters including CK-MB, sodium, potassium, chlorides, magnesium and ALP at concentration of 500mg/L Intralipid®. For the test recovery the DSI criteria were not met for calcium, total protein, sodium and chlorides after high speed centrifugation and for glucose, calcium, phosphates, magnesium, sodium, potassium, chlorides, ALP, GGT, CK-MB, total protein, albumin and troponin T after using LipoClear®. CONCLUSIONS: LipoClear® is not suitable for lipemia removal from samples designated for glucose, sodium, potassium, chlorides, phosphates, magnesium, CK-MB, ALP, GGT, total protein, albumin, CRP and troponin T measurements. High speed centrifugation should be used for lipemia removal instead for glucose, potassium, phosphates, magnesium, CK-MB, ALP, GGT, albumin, CRP and TnT measurements.

High-efficiency removal of phytic acid in soy meal using two-stage temperature-induced Aspergillus oryzae solid-state fermentation.

BACKGROUND: Phytic acid of soy meal (SM) could influence protein and important mineral digestion of monogastric animals. Aspergillus oryzae (ATCC 9362) solid-state fermentation was applied to degrade phytic acid in SM. Two-stage temperature fermentation protocol was investigated to increase the degradation rate. The first stage was to maximize phytase production and the second stage was to realize the maximum enzymatic degradation. RESULTS: In the first stage, a combination of 41% moisture, a temperature of 37 °C and inoculum size of 1.7 mL in 5 g substrate (dry matter basis) favored maximum phytase production, yielding phytase activity of 58.7 U, optimized via central composite design. By the end of second-stage fermentation, 57% phytic acid was degraded from SM fermented at 50 °C, compared with 39% of that fermented at 37 °C. The nutritional profile of fermented SM was also studied. Oligosaccharides were totally removed after fermentation and 67% of total non-reducing polysaccharides were decreased. Protein content increased by 9.5%. CONCLUSION: Two-stage temperature protocol achieved better phytic acid degradation during A. oryzae solid state fermentation. The fermented SM has lower antinutritional factors (phytic acid, oligosaccharides and non-reducing polysaccharides) and higher nutritional value for animal feed.

Oxidative stability of soybean oil in oleosomes as affected by pH and iron.

The oxidative stability of oil in soybean oleosomes, isolated using the Enzyme-Assisted Aqueous Extraction Process (EAEP), was evaluated. The effects of ferric chloride, at two concentration levels (100 and 500 µM), on lipid oxidation, was examined under pH 2 and 7. The peroxide value (PV) and thiobarbituric acid-reactive substance (TBARS) value of oil, in oleosome suspensions stored at 60 °C, were measured over a 12 day period. The presence of ferric chloride significantly (P<0.05) affected the oxidative stability of oil in the isolated oleosome, as measured by the PV and TBARS. Greater lipid oxidation occurred under an acidic pH. In the pH 7 samples, the positively charged transition metals were strongly attracted to the negatively charged droplets. However, the low ζ-potential and the high creaming rate at this pH, may have limited the oxidation. Freezing, freeze-drying or heating of oleosomes have an insignificant impact on the oxidative stability of oil in isolated soybean oleosomes. Manufacturers should be cautious when adding oleosomes as ingredients in food systems containing transition metal ions.

Effects of high-pressure process on kinetics of leaching oil from soybean powder using hexane in batch systems.

UNLABELLED: Mass transfer models of leaching oil from soybean (Glycine max) flour with hexane after high-pressure process (HPP) treatment were developed. High pressure (450 MPa) was applied to the soybean flour (mean diameter of flour particle: 365 µm) for 30 min before leaching the oil components in the solvent. The ratio of solvent (volume, mL) to soybean flour (mass, g), such as 1:10 and 1:20, was employed to characterize the effect of solvent ratio on the leaching rate in the batch type of extraction process. Ultraviolet absorbance at 300 nm was used to monitor the extraction rate. Saturation solubility (C(AS)) was determined to be 21.73 kg/m³. The mass transfer coefficients (k) were determined based on the 1st- and 2nd-order kinetic models. The 2nd kinetic model showed better fit. The HPP treatment showed a higher extraction rate and yield compared to the control, while the amount of solvent did not affect the extraction rate and yield. The scanning electron microscope showed that HPP-treated soybean particles included more pores than the untreated. The pores observed in the HPP-treated soybean flours might help increase the mass transfer rate of solvent and solute in the solid matrix. PRACTICAL APPLICATION: High-pressure processing can help increase the extraction rate of oil from the soybean flour operated in batch systems. The conventional solid to solvent ratio (1:20) used to extract oil composition from the plant seed did not help increase the amount of oil extracted from the soybean flour.

Process improvement for semipurified oleosomes on a pilot-plant scale.

Semipurified oleosomes were isolated on a pilot-plant scale using improved-process extraction conditions. The improved process consisted of continuous centrifugation in a three-phase decanter with recirculation of slurry until most of the oleosomes were recovered. Oleosome fractionation, oleosin identification, and isoflavone and saponin mass distributions and recoveries were investigated. The improved pilot-plant oleosome extraction process was achieved in 8 h. A total of 91%± 1% of soybean oil was recovered as intact oleosomes. The oil content of the aqueous supernatant and the residue fractions were low at 2% and 3%, respectively. The aqueous supernatant fraction contained 40% total soybean protein. About 76% of the proteins present in the oleosome fraction were soybean storage proteins. Washing the semipurified oleosomes with a 0.1 M Tris-HCl, pH 8.6 containing 0.4 M sucrose, and 0.5 M NaCl resulted in the recovery of the associated storage proteins. The recovery of these proteins in addition to the protein in aqueous supernatant accounted for 79% of the total soybean storage proteins fractionated by this process. Oleosins were detected at 17 and 18 kDa. Isoflavones and saponins partitioned into the oleosome, aqueous supernatant, and residue fractions at different ratios with the majority, about 82 and 63 mole%, respectively, in oleosome and aqueous supernatant fractions, making these fractions an attractive source for phytochemicals.

Simple extraction method of non-allergenic intact soybean oil bodies that are thermally stable in an aqueous medium.

This study supplied a simple extraction method for intact soybean oil body (ISOB) and examined the heating effect on ISOB. ISOB, which just contained its intrinsic protein (oleosin), could be obtained by pH 11 extraction (50000g, 45 min). ISOB suspension was dialyzed to deionized water (1:3600) and named DISOB. DISOB aggregated at pH 5.7, but NaCl pre-addition (5-500 mM) made ISOB disperse well at pH 5.7. The heating (30, 40, 50, 60, 70, 80, and 90 degrees C and boiling water baths, 30 min) did not affect the particle size distributions of ISOB. The pH and CaCl(2) effects on DISOB and its surface hydrophobicity were also not affected by heating (>95 degrees C, 5 min). Both unheated and heated ISOB were bound to native soybean protein but were not bound to the heat-denatured one. Thus, it was suggested that ISOB changed little by heating. This study was meaningful in two aspects: (1) pH 11 extraction removed beta-conglycinin, glycinin, and allergenic proteins (such as Gly m Bd 30K), and the obtained ISOB had good stability in an aqueous medium. (2) Heating could denature the contamination allergenic proteins.

Mechanisms of aqueous extraction of soybean oil.

Aqueous extraction processing (AEP) of soy is a promising green alternative to hexane extraction processing. To improve AEP oil yields, experiments were conducted to probe the mechanisms of oil release. Microscopy of extruded soy before and after extraction with and without protease indicated that unextracted oil is sequestered in an insoluble matrix of denatured protein and is released by proteolytic digestion of this matrix. In flour from flake, unextracted oil is contained as intact oil bodies in undisrupted cells, or as coalesced oil droplets too large to pass out of the disrupted cellular matrix. Our results suggest that emulsification is an important extraction mechanism that reduces the size of these droplets and increases yield. Protease and SDS were both successful in increasing extraction yields. We propose that this is because they disrupt a viscoelastic protein film at the droplet interface, facilitating droplet disruption. An extraction model based on oil droplet coalescence and the formation of a viscoelastic film was able to fit kinetic extraction data well.

Gravity separation of pericardial fat in cardiotomy suction blood: an in vitro model.

Fat emboli generated during cardiac surgery have been shown to cause neurologic complications in patients postoperatively. Cardiotomy suction has been known to be a large generator of emboli. This study will examine the efficacy of a separation technique in which the cardiotomy suction blood is stored in a cardiotomy reservoir for various time intervals to allow spontaneous separation of fat from blood by density. Soybean oil was added to heparinized porcine blood to simulate the blood of a patient with hypertriglyceridemia (> 150 mg/dL). Roller pump suction was used to transfer the room temperature blood into the cardiotomy reservoir. Blood was removed from the reservoir in 200-mL aliquots at 0, 15, 30 45, and 60 minutes. Samples were taken at each interval and centrifuged to facilitate further separation of liquid fat. Fat content in each sample was determined by a point-of-care triglyceride analyzer. Three trials were conducted for a total of 30 samples. The 0-minute group was considered a baseline and was compared to the other four times. Fat concentration was reduced significantly in the 45- and 60-minute groups compared to the 0-, 15-, and 30-minute groups (p < .05). Gravity separation of cardiotomy suction blood is effective; however, it may require retention of blood for more time than is clinically acceptable during a routing coronary artery bypass graft surgery.

Anti-oxidative effects of rooibos tea extract on autoxidation and thermal oxidation of lipids.

Powdered rooibos tea extract (RTE), which is rich in polyphenols, is made from rooibos tea by freeze-drying. "Rooibos" is Afrikaans for "red bush," and the scientific name is "Aspalathus linearis." It is a broom-like member of the legume family of plants and is used to make an herbal tea which has been popular in South Africa for generations and is now consumed in many countries. In the present work, the anti-oxidative effect of RTE on oils and fats in autoxidation or thermal oxidation was studied, and it was confirmed that RTE has a very strong anti-oxidative effect on emulsifying oils owing to the water-soluble polyphenols such as rutin and quercetin contained in RTE. RTE was found to have a strong ability to quench radicals generated in the water phase, and to confer higher thermal stability against deep fat frying than tocopherol. But RTE showed little anti-oxidative effect on frying oil because of its lower oil-solubility.

Enzymatic production of trans-free hard fat stock from fractionated rice bran oil, fully hydrogenated soybean oil, and conjugated linoleic Acid.

Rice bran oil (RBO) was fractionated into 2 phases, solid (S-RBO) and liquid (L-RBO), using acetone at -18 degrees C and the weight yield of each S-RBO and L-RBO was 45.5% and 54.5%, respectively. Then, trans-free hard fat was synthesized from trans-free substrate of S-RBO and fully hydrogenated soybean oil (FHSBO) at different molar ratios (S-RBO : FHSBO; 1 : 1, 1 : 1.5, 1 : 2, and 1 : 3) with Lipozyme TL IM lipase (10% of total substrate). Conjugated linoleic acid (CLA, 20% of total substrate) was used as functional fatty acids for the production of trans-free hard fat. After fatty acid analysis, CLA (12.2% to 14.2%) was found on the triacylglycerol (TAG) backbone of the interesterified products along with stearic (37.6% to 49%), palmitic (15% to 17.9%), and oleic acids (13.3% to 19.2%). The interesterified product contained higher level of saturated fatty acid (62.6% to 70.1%) at sn-2 position. Total tocopherols (alpha-, gamma-, and delta-; 1.4 to 2.6 mg/100 g) and phytosterols (campesterol, stigmasterol, and beta-sitosterol; 220.5 to 362.7 mg/100 g) were found in the interesterified products. From DSC results, solid fat contents of the interesterified products (S-RBO : FHSBO 1 : 1, 1 : 1.5, 1 : 2, and 1 : 3) at 25 degrees C were 23.1%, 27%, 30.1%, and 44.9%. The interesterified products consisted mostly of beta' form crystal with a small portion of beta form. The interesterified product (S-RBO : FHSBO 1 : 1.5) was softer than the physical blend but slightly harder than commercial shortenings as measured by texture analyzer. Thus, trans-free hard fat stock, which may have a potential functionality could be produced with various physical properties.

Demulsification of oil-rich emulsion from enzyme-assisted aqueous extraction of extruded soybean flakes.

Extraction of soybean oil from flaked and extruded soybeans using enzyme-assisted aqueous extraction processing (EAEP) is a promising alternative to conventional hexane extraction. The efficiencies of four proteases releasing oil from extruded material were compared. Protex 51FP, Protex 6L and Protex 7L each extracted 90% of the total oil available while Protex 50FP gave similar extraction yield as the control (without enzyme treatment). During EAEP, however, a stable emulsion forms that must be broken in order to recover free soybean oil. The potential of various proteases and phospholipases to destabilize the emulsion was determined. Two enzymes, a phospholipase A2 (LysoMax) and a protease (Protex 51FP) were selected to determine the effect of enzyme concentration on demulsification. Although at a 2% concentration (w/w, enzyme/(cream+free oil)), each enzyme tested was effective in totally destabilizing the cream; the protease released significantly more free oil than did the phospholipase at concentrations less than 2%. At 0.2% concentration, 88 and 48% of free oil were obtained with the protease and phospholipase, respectively. Reducing the pH of the cream also destabilized the cream with maximum demulsification at the isoelectric point of soy proteins. These results provide destabilization strategies for the oil-rich emulsion formed during aqueous extraction processing of extruded flakes and significantly contribute to the development of this environmentally-friendly technology.

Extraction and characterization of oil bodies from soy beans: a natural source of pre-emulsified soybean oil.

Soybeans contain oil bodies that are coated by a layer of oleosin proteins. In nature, this protein coating protects the oil bodies from environmental stresses and may be utilized by food manufacturers for the same purpose. In this study, oil bodies were extracted from soybean using an aqueous extraction method that involved blending, dispersion (pH 8.6), filtration, and centrifugation steps. The influence of NaCl (0-250 mM), thermal processing (30-90 degrees C, 20 min) and pH (2-8) on the properties and stability of the oil bodies was analyzed using zeta-potential, particle size, and creaming stability measurements. The extracted oil bodies were relatively small ( d 32 approximately 250 nm), and their zeta-potential went from around +12 mV to -20 mV as the pH was increased from 2 to 8, with an isoelectric point around pH 4. The oil bodies were stable to aggregation and creaming at low (pH = 2) and high (pH >/= 6) pH values but were unstable at intermediate values (3

Natural compounds obtained through centrifugal molecular distillation.

Soybean oil deodorized distillate (SODD) is a byproduct from refining edible soybean oil; however, the deodorization process removes unsaponifiable materials, such as sterols and tocopherols. Tocopherols are highly added value materials. Molecular distillation has large potential to be used in order to concentrate tocopherols, because it uses very low levels of temperatures because of the high vacuum and short operating time for separation and, also, it does not use solvents. However, nowadays, the conventional way to recover tocopherols is carrying out chemical reactions prior to molecular distillation, making the process not so suitable to deal with natural products. The purpose of this work is to use only molecular distillation in order to recover tocopherols from SODD. Experiments were performed in the range of 140-220 degrees C. The feed flow rate varied from 5 to 15 g/min. The objective of this study was to remove the maximum amount of free fatty acids (FFA) and, so, to increase the tocopherol concentration without add any extra component to the system. The percentage of FFA in the distillate stream of the molecular still is larger at low feed flow rates and low evaporator temperatures, avoiding thermal decomposition effects.

Recovery of oil components of okara by ethanol-modified supercritical carbon dioxide extraction.

Recovery of the oil components of okara by ethanol-modified supercritical carbon dioxide extraction was investigated at 40-80 degrees C temperature and 12-30 MPa pressure. In a typical run (holding period of 2 h, continuous flow extraction of 5 h), results indicated that the oil component could be best obtained with a recovery of 63.5% at relatively low temperature of 40 degrees C and mild pressure of 20 MPa in the presence of 10 mol% EtOH as entrainer. Based on gas chromatography-mass spectrometry (GC-MS) analysis, the extracts consisted mainly of fatty acids and phytosterols, and traces of decadienal. Folin-Ciocalteau estimates of total phenols showed that addition of EtOH as entrainer increased the yield and the amount of phenolic compounds in the extracts. The amounts of two primary soy isoflavones, genistein and daidzein, in the extracts also increased with increasing amount of EtOH.

Extraction of soybean oil from single cells.

Single cells prepared from autoclaved soybeans and cellulase treatment of the cells were effective in digesting the cell walls of and extracting the oil from soybeans. The first cell wall of the soybean single cell was completely removed using cellulases; the thin and transparent second cell wall of the cell was swollen. Oil in the cell formed spherical or hemispherical oil drops, and oil leaking from the oil bodies was observed. The oil was almost retained within the second cell wall. Water-extractable substances were obtained at approximately >60% of the weight. Flotation of oil drops by centrifugation was easily done. Ambient n-hexane extraction was also possible; however, residual oil remained in the oil bodies. Protease or peptidase digested the structure of the oil bodies; however, separation of the oil and the hydrolysates was impossible. The oil from the oil bodies was obtained effectively (>85%) by pressing the single cells and/or cellulase-treated single cells.