Soybean Oil Deodorizer Distillate Research Articles

A two steps enzymatic procedure to obtain sterol esters, tocopherols and fatty acid ethyl esters from soybean oil deodorizer distillate

Soybean oil deodorizer distillate (SODD) was enzymatically modified to obtain a product mixture comprised mainly of sterol esters, tocopherols, and fatty acid ethyl esters. Firstly, the original SODD was mixed with oleic acid to reduce its melting point from 65–70 to 30–35 °C and also to produce a reaction mixture with a ratio of free fatty acids (FFA) to sterols close to 2 to improve the progress of sterols esterification. Two enzymatic steps were used in order to separate sterols esterification and ethyl esterification in time and space. The first enzymatic step (in the presence of Candida rugosa lipase) allowed to efficiently transform more than 90% of the original sterols in a short period of time (5 h). The second enzymatic step (in the presence of Novozym 435) converted more than 95% of the FFA in less than 3 h. In addition, the stability of both biocatalysts has been evaluated and both bioprocesses have been scaled-up reutilizing the same batch of lipase up to 8 and 3 times for the first and the second enzymatic step, respectively. The final product obtained is intended to be used as starting material for the purification of sterol esters, tocopherols, and fatty acid ethyl esters via supercritical fluid extraction.

Improved methanol tolerance during Novozym435-mediated methanolysis of SODD for biodiesel production

SODD is proposed here as a sort of feedstock for biodiesel production. During lipase-catalyzed alcoholysis of soybean oil deodorizer distillate (SODD) for biodiesel production, lipase expressed higher tolerance to methanol compared to that with refined soybean oils as the feedstock, and much a faster reaction rate could be obtained. Further study showed that free fatty acid contained in SODD was the major factor contributing to the improvement of lipase tolerance to methanol. It was further demonstrated that the improved methanol tolerance was related to the hydrophobicity of the reactants (log Preactant), the lower the ∣log Preactant − log Pinterface∣, the higher the lipase tolerance to methanol that could be achieved. The highest biodiesel yield of 95% could be achieved by adding a 3 A molecular sieve as an adsorbent into the system to control the by-product water.

PHASE EQUILIBRIUM FOR SUPERCRITICAL CO2 AND THE METHYL ESTERIFIED PRODUCT FROM SOYBEAN OIL DEODORIZER DISTILLATE

ABSTRACT In order to study the feasibility of using supercritical CO2 (SC‐CO2) to concentrate natural tocopherols from soybean oil deodorizer distillate (DOD), the vapor–liquid phase equilibrium data were determined for SC‐CO2 and methyl esterified DOD (ME‐DOD) at 40C and in the pressure range of 9.7–16.2 MPa. A vapor and liquid phase circulation apparatus was employed. The samples from the liquid and vapor phases were analyzed by gas chromatography and high‐performance liquid chromatography methods. According to the determined data, the distribution coefficient and separation factor were calculated and discussed. The results showed that the separation factor between tocopherols and fatty acid methyl esters was from 2.5 to 3.8 at 40C and 9.7–16.2 MPa, which is fundamental and necessary for future process designs.

Lipase-catalyzed biodiesel production from soybean oil deodorizer distillate with absorbent present in tert-butanol system

Lipase-catalyzed alcoholysis of soybean oil deodorizer distillate (SODD) for biodiesel production was studied. During this system both free fatty acids and glycerides could be converted to biodiesel simultaneously. tert-Butanol has been adopted as the reaction medium, in which both the negative effects caused by excessive methanol and by-product glycerol could be eliminated completely. There was no obvious loss in lipase activity even after being repeatedly used for 120 cycles. Fine-pored silica gel and 3 Å molecular were found to be effective to control by-product water concentration and much higher biodiesel yield could be achieved with those adsorbents present in the reaction system. The highest biodiesel yield of 97% could be achieved with 3 Å molecular sieve as the adsorbent.

Comparison of Two Different Strategies for Tocopherols Enrichment Using a Molecular Distillation Process

The objective of this study is to compare two different strategies for enriching tocopherols in soybean oil deodorizer distillate (SODD) using a molecular distillation process. The first strategy is to submit crude SODD to a sequence of molecular distillations using different temperatures without any preparation of the raw material. The second strategy is to modify chemically the raw material and submit it to a sequence of distillations. In SODD chemical modification, acylglycerol species are converted into free fatty acids (FFAs) and glycerol through a saponification reaction at 65 °C followed by an acidulation step. Crude and chemically modified SODD were submitted to five stages of molecular distillation to evaluate and compare the performance of both sequences of distillations. It was observed that the enrichment of tocopherols was 4.1 and 5.8 times higher than the original feed concentration for crude and chemically modified SODD, respectively.

Improvement of a process for purification of tocopherols and sterols from soybean oil deodorizer distillate

Soybean oil deodorizer distillate (SODD) is a useful material for purification of tocopherols and phytosterols (referred to as sterols). The SODD was first distilled, and the two substances were enriched. The preparation, which mainly contained free fatty acids (FFAs), sterols, and tocopherols, was named SODD tocopherols/sterols concentrate (SODDTSC). If sterols are converted to steryl esters and FFAs are converted to fatty acid methyl esters (FAMEs), relatively easy purification of tocopherols and steryl esters can be achieved because the boiling points of FAMEs, tocopherols, and steryl esters are different significantly. Hence, the development of a new two-step in situ reaction system was tried out for esterification of sterols with FFAs (first step) and esterification of FFAs with methanol (MeOH) (second step). A mixture of SODDTSC/water (95:5, w/w) and 250 units (U)/g-mixture of Candida rugosa lipase was prepared beforehand for the first-step reaction, and was agitated at 40 °C for 24 h with dehydration at 20 mmHg. Sterols were efficiently esterified, and the degree of esterification reached 95%. To the reaction mixture were added 7 M amounts of MeOH against unreacted FFAs, 20 wt.% water, and 25 U/g-mixture of Alcaligenes sp. lipase. The second-step reaction was then conducted at 30 °C for 20 h. Consequently, 95% FFAs were converted to FAME, and steryl esters synthesized by the first-step reaction were not reconverted to free sterols. Finally, SODDTSC (1.5 kg) was subjected to this two-step in situ reaction, and tocopherols and steryl esters were purified from the reaction mixture by short-path distillation. Tocopherols were purified to 72% (yield, 88%) and steryl esters were purified to 97% (yield, 97%).

Free fatty acid separation from vegetable oil deodorizer distillate using molecular distillation process

Distillates of the vegetable oil deodorization are composed of free fatty acids (FFA), sterols, tocopherols, sterol esters, hydrocarbons and breakdown products of fatty acids, aldehydes, ketones and acylglycerols. The content of free fatty acids in deodorizer distillates varies between 25 and 75%. Due to its high content, free fatty acid separation from deodorizer distillate is an important step to concentrate tocopherols to high purity. Tocopherols are valuable natural substances used in food, cosmetic and pharmaceutical industries. In this work, separation of free fatty acids from soybean oil deodorizer distillate (SODD) was investigated through molecular distillation, using different operating conditions. Evaporator temperature from 100 to 180 °C and feed flow rate in the range of 1.5–23.0 g min −1 were used in the experiments. FFA and tocopherols contents were monitored in each stream generated by the molecular distillation process (distillate and residue streams). The intention is to determine the best operating conditions to produce a material with minimum FFA content and to minimize tocopherol losses during the process. Removal of FFA in the distillate stream resulted in a preliminary concentration of tocopherols, which is removed in the residue stream of the molecular distillation. The results showed that an efficient FFA separation from SODD with the lowest loss of tocopherols requires specific operating conditions. It was possible to obtain a material with 6.4% of FFA and 18.3% of tocopherols from a raw material composed by 57.8% of FFA and 8.97% of tocopherols, using 160 °C of evaporator temperature and 10.4 g min −1 of feed flow rate. These results represent FFA elimination of 96.16% and tocopherol recovery of 81.23%.

Phase Equilibria for the Ternary System Methyl Oleate + Tocopherol + Supercritical CO2

To study the feasibility of using supercritical CO2 to concentrate natural tocopherols from soybean oil deodorizer distillate (DOD), we measured the ternary phase equilibrium data for methyl oleate + α-tocopherol + supercritical CO2 from (313.15 to 353.15) K in the pressure range from (10 to 29) MPa. The measured data were well correlated using the Soave−Redlich−Kwong EOS with the Adachi−Sugie mixing rule. The separation factor between methyl oleate and tocopherol in CO2 was investigated. On the basis of these results, equilibrium lines in the experimental ranges were obtained that provide fundamental data for concentrating tocopherols with supercritical CO2. In addition, because the distribution of tocopherol in supercritical CO2 increases markedly because of the abundance of methyl oleate, methyl oleate was shown to act as a cosolvent for tocopherol. Finally, according to the obtained results, a strategy for a separation operation was suggested. Visual observation also provided information useful in fur...

Recovery of sterols as fatty acid steryl esters from waste material after purification of tocopherols

Tocopherols are purified industrially from soybean oil deodorizer distillate by a process comprising distillation and ethanol fractionation. The waste material after ethanol fractionation (TC waste) contains 75% sterols, but a purification process has not yet been developed. We thus attempted to purify sterols by a process including a lipase-catalyzed reaction. Candida rugosa lipase efficiently esterified sterols in TC waste with oleic acid (OA). After studying several factors affecting esterification, the reaction conditions were determined as follows: ratio of TC waste/OA, 1:2 (wt/wt); water content, 30%; amount of lipase, 120 U/g-reaction mixture; temperature, 40 degrees C. Under these conditions, the degree of esterification reached 82.7% after 24 h. FA steryl esters (steryl esters) in the oil layer were purified successfully by short-path distillation (purity, 94.9%; recovery, 73.1%). When sterols in TC waste were esterified with FFA originating from olive, soybean, rapeseed, safflower, sunflower, and linseed oils, the FA compositions of the steryl esters differed somewhat from those of the original oils: The content of saturated FA was lower and that of unsaturated FA was higher. The m.p. of the steryl esters synthesized (21.7-36.5 degrees C) were remarkably low compared with those of the steryl esters purified from high-b.p. soybean oil deodorizer distillate substances (56.5 degrees C; JAOCS 80, 341-346, 2003). The low-m.p. steryl esters were soluble in rapeseed oil even at a final concentration of 10%.

Purification of tocopherols and phytosterols by a two‐step in situ enzymatic reaction

AbstractThe purification of tocopherols and phytosterols (referred to as sterols) from soybean oil deodorizer distillate (SODD) was attempted. Tocopherols and sterols in the SODD were first recovered by short‐path distillation, which was named sODD tocopherol/sterol concentrate (SODDTSC). The SODD‐TSC contained MAG, DAG, FFA, and unidentified hydrocarbons in addition to the two substances of interest. It was then treated with Candida rugosa lipase to convert sterols to FA steryl esters, acylglycerols to FFA, and FFA to FAME. Methanol (MeOH), however, inhibited esterification of the sterols. Hence, a two‐step in situ reaction was conducted: SODDTSC was stirred with 20 wt% water and 200 U/g mixture of C. rugosa lipase at 30°C, and 2 moles of MeOH per mole of FFA was added to the reaction mixture after 16h. The lipase treatment for 40 h in total achieved 80% conversion of the initial sterols to FA steryl esters, complete hydrolysis of the acylglycerols, and a 78% decrease in the initial FFA content by methyl esterification. Tocopherols did not change throughout the process. To enhance the degree of steryl and methyl esterification, the reaction products, FA steryl esters and FAME, were removed by short‐path distillation, and the resulting fraction containing tocopherols, sterols, and FFA was treated with the lipase again. Distillation of the reaction mixture purified tocopherols to 76.4% (recovery, 89.6%) and sterols to 97.2% as FA steryl esters (recovery, 86.3%).

Phase equilibria for binary systems of methyl oleate–supercritical CO 2 and α-tocopherol–supercritical CO 2

In order to study the possibility of using supercritical CO 2 to concentrate tocopherols from soybean oil de-odorizer distillate (DOD), the binary phase equilibrium data for methyl oleate–CO 2 and α-tocopherol–CO 2 were measured at 313.15–353.15 K in the pressure ranges of 5–23 MPa for methyl oleate and 5–30 MPa for α-tocopherol, respectively. The measured data were well correlated using the Soave–Redlich–Kwong (SRK) equation of state (EOS) with the Adachi–Sugie (AS) mixing rule. The solubilities and distribution coefficients of methyl oleate and α-tocopherol in CO 2 were investigated. Finally, on the basis of these results, a conclusion was preliminarily drawn, supercritical CO 2 can be used to concentrate natural tocopherols from the esterified DOD in the experimental range investigated. In addition, the critical points of methyl oleate–CO 2 at three temperatures were estimated.

Purification of steryl esters from soybean oil deodorizer distillate

AbstractSoybean oil deodorizer distillate (SODD) contains steryl esters in addition to tocopherols and sterols. Tocopherols and sterols have been industrially purified from SODD but no purification process for steryl esters has been developed. SODD was efficiently separated to low b.p. substances (including tocopherols and sterols) and high b.p. substances (including 11.2 wt% DAG, 32.1 wt% TAG, and 45.4 wt% steryl esters) by molecular distillation. The high b.p. fraction is referred to as soybean oil deodorizer distillate steryl ester concentrate (SODDSEC). We attempted to purify steryl esters after a lipase‐catalyzed hydrolysis of acylglycerols in SODDSEC. Screening of industrially available lipases indicated that Candida rugosa lipase was most effective. Based on the study of several factors affecting hydrolysis, the reaction conditions were determined as follows: ratio of SODDSEC/water, 1∶1 (w/w); lipase amount, 15 U/g reaction mixture; temperature, 30°C. When SODDSEC was agitated for 24 h under these conditions, acylglycerols were almost completely hydrolyzed and the content of steryl esters did not change. However, study with a mixture of steryl oleate/trilinolein (1∶1, w/w) indicated that about 20% of constituent FA in steryl esters were exchanged with constituent FA in acylglycerols. Steryl esters in the oil layer obtained by the SODDSEC treatment with lipase were successfully purified by molecular distillation (purity, 97.3%; recovery, 87.7%).

Optimización del proceso de esterificación química del destilado de desodorización del aceite de soja previamente saponificado y acidulado

In this research work, it was optimized the reaction conditions for the chemistry esterification of unsaponifiable matter in soybean oil deodorizer distillate. The process involves (i) alkaline hydrolysis of saponifiable matter; (ii) acidulation of soaps and (iii) acid catalyzed esterification of resulting total fatty acid. To determine the best process conditions to get the higher conversion rates of total fatty acids to ethylic esters, preserving the tocopherols, it was used, to analyze the results, the response surface methodology in a 2nd order factorial planning. In the step (i) saponification of soybean oil deodorizer distillate saponifiable matter using NaOH:total fatty acids molar ratio = 2:1, temperature = 80o C and reaction time of 40 min. In the step (ii) the resulting soaps were rapidly and stoichiometrically converted in free fatty acids with sulfuric acid (23 %), using an acid molar excess of 50 %, at 80o C, for 40 min and under atmospheric pressure. In the step (iii) the optima conditions for the esterification reaction of soybean oil deodorizer distillate were: ethanol:total fatty acids molar ratio from 6.4 to 11.2:1, SO 2 H 4 concentration from 0.9 to 1.5 % and reaction time from 1.3 to 2.6 h, with ethyl esters conversion rates up to 98 %. The mathematical model obtained is predictive and statistically significant (p<0,05). The total tocopherol losses during the process were less than 10,5 %.

Optimization of direct acid esterification process of soybean oil deodorizer distillate

In this research work, the reaction conditions for the direct acid esterification of free fatty acid from soybean oil deodorizer distillate was optimized, using anhydrous ethyl alcohol and concentrated sulfuric acid as catalyst to determine the best process conditions to get the best conversion rates of free fatty acids to ethylic esters, preserving the tocopherols. The conversion extent of free fatty acids to ethyl esters was optimized using a Response Surface Methodology obtained through a second order factorial experimental design. The optima conditions for the direct acid esterification of soybean oil deodorizer distillate were: ethanol:free fatty acids from 6.4 to 11.2:1, H 2 SO 4 concentration from 0.9 to 1.5 % and reaction time from 1.3 to 2.6 h, with conversions extent above 94 %. No significant tocopherol losses were observed during the process. Results showed a good fit between mathematical model and data obtained at different processing conditions, making this model predictive and statistically significant (p< 0,05).

α- and γ-tocopherol levels in Nelore steer blood plasma after a single oral treatment of soybean oil deodorizer distillate (SODD)

The paper presents a study on the effect of a treatment of steers with a single oral dose of soybean oil deodorizer distillate (SODD) on the α- and γ-tocopherol blood plasma concentrations. SODD containing 1.95% of α-tocopherol and 8.45% of γ-tocopherol in doses of 0.75, 1.50 or 2.25g/kg live weight was used on nine 2-year-old Nelore ( Bos indicus) steers to promote increases in the plasma concentration of vitamin E. Tocopherol analyses were performed by HPLC on a C18 column, using a UV detector. The results showed that a single oral treatment of steers with SODD produces significant increases in plasma α- and γ-tocopherol levels. The vitamin E content was increased up to four times the initial content, showing the high capacity of SODD as a source of vitamin E for bovines in a single oral dose with the objective of increasing vitamin E blood plasma concentrations and, consequently, the levels in the tissues, as well.

Supercritical Carbon Dioxide Extraction of High-Value Substances from Soybean Oil Deodorizer Distillate

This work attempted to recover high-value substances such as free fatty acids, tocopherols, sterols, and squalene by investigating a supercritical fluid CO 2 (SF CO 2 ) distillation-extraction processing of soybean oil deodorizer distillate. Experimental conditions varied between 50 and 90 °C, at 24.1 and 31.0 MPa. Reverse-phase high-performance liquid chromatography analysis was performed to analyze 14 components in the extracts after SF CO 2 treatment. Experimental results indicated that when tocopherols were extracted at 31.0 MPa, 90 (top) to 70 (bottom) °C, and 1000-L STP CO 2 usage, their recovery reached 83.6% and the average value of the concentration factor was 1.38. Furthermore, the concentration factor of tocopherols grew to 1.70 when the extracts collected in the top exceeded 400-L STP CO 2 . The concentration factors of fatty acids, squalene, and stereols were 1.37, 1.26, and 0.60, respectively. This investigation also found that the percentage of total fatty acids decreased, while polyunsaturated fatty acids increased, with an increase in the CO 2 volume given the same extraction condition.

Facile purification of tocopherols from soybean oil deodorizer distillate in high yield using lipase

AbstractTocopherols have been purified from deodorizer distillate produced in the final deodorization step of vegetable oil refining by a process including molecular distillation. Deodorizer distillate contains mainly tocopherols, sterols, and free fatty acids (FFA); the presence of sterols hinders tocopherol purification in good yield. We found that Candida rugosa lipase recognized sterols as substrates but not tocopherols, and that esterification of sterols with FFA could be effected with negligible influence of water content. Enzymatic esterification of sterols with FFA was thus used as a step in tocopherol purification. High boiling point substances including steryl esters were removed from soybean oil deodorizer distillate by distillation, and the resulting distillate (soybean oil deodorizer distillate tocopherol concentrate; SODDTC) was used as a starting material for tocopherol purification. Several factors affecting esterification of sterols were investigated, and the reaction conditions were determined as follows: A mixture of SODDTC and water (4∶1, w/w) was stirred at 35°C for 24 h with 200 U of Candida lipase per 1 g of the reaction mixture. Under these conditions, approximately 80% of sterols was esterified, but tocopherols were not esterified. After the reaction, tocopherols and FFA were recovered as a distillate by molecular distillation of the oil layer. To enhance further removal of the remaining sterols, the lipase‐catalyzed reaction was repeated on the distillate under the same reaction conditions. As a result, more than 95% of the sterols was esterified in total. The resulting reaction mixture was fractionated to four distillates and one residue. The main distillate fraction contained 65 wt% tocopherols with low contents of FFA and sterols. In addition, the residue fraction contained high‐purity steryl esters. Because the process presented in this study includes only organic solvent‐free enzymatic reaction and molecular distillation, it is feasible as a new industrial purification method of tocopherols.

7500. Properties of reactively sputtered NbN films: K L Westra et al,J Vac Sci Technol, A8, 1990, 1288–1293

Lipase-catalyzed alcoholysis of soybean oil deodorizer distillate (SODD) for biodiesel production was studied. During this system both free fatty acids and glycerides could be converted to biodiesel simultaneously. tert-Butanol has been adopted as the reaction medium, in which both the negative effects caused by excessive methanol and by-product glycerol could be eliminated completely. There was no obvious loss in lipase activity even after being repeatedly used for 120 cycles. Fine-pored silica gel and 3 Å molecular were found to be effective to control by-product water concentration and much higher biodiesel yield could be achieved with those adsorbents present in the reaction system. The highest biodiesel yield of 97% could be achieved with 3 Å molecular sieve as the adsorbent.