Formation Of Trans Fatty Acids Research Articles

Effects of frying on the trans‐fatty acid formation in soybean oils

AbstractTo evaluate the effects of repeated deep‐frying on the trans‐fatty acid (TFA) formation in soybean oils, simultaneous frying experiments were carried out. French fries were prepared using three different types of soybean oil (pressed soybean oil, PSBO; first‐grade solvent extracted soybean oil, FG‐SESBO; and third‐grade solvent extracted soybean oil, TG‐SESBO). French fries were fried intermittently at 180–185°C for a total frying time of 32 h and at an interval time of 30 min. It was found that the initial amount of total TFAs was 0.29 g/100 g, 0.31 g/100 g, and 0.90 g/100 g in PSBO, TG‐SESBO, and FG‐SESBO, respectively. Before the frying started, the C18:1,t‐9, trans‐linoleic acid (TLA), trans‐linolenic acid (TLNA), and total TFA content of the PSBO and TG‐SESBO were significantly lower than in the FG‐SESBO (p<0.05). However, in the frying oil samples, the final concentration of total TFA in the PSBO, TG‐SESBO, and FG‐SESBO were 1.79 ± 0.17 g/100 g, 1.12 ± 0.10 g/100 g, and 1.70 ± 0.07 g/100 g, which was 6.17‐, 3.61‐, and 1.89‐fold higher that in fresh oil, respectively. The highest increasing slopes of C18:1,t‐9, TLA, TLNA, and total TFA were observed in the PSBO.Practical applications: A high intake of TFAs has been shown to lead to an increased risk of coronary heart disease. Plant oils, particularly soybean oil, have been widely used in the food industry in China. Frying is one of the most common methods to cook food. The formation of TFAs during frying has been shown to be closely related to the temperature and duration of the frying process. However, the effects of frying on the formation of TFAs in different soybean oils have not been well studied. In the present study, we demonstrated that increasing the number of frying cycles can cause an intensive increase in the concentration of TFAs in different types of soybean oil, but especially in PSBO.

Effect of frying conditions on the physico-chemical properties of rice bran oil and its blended oil.

The changes occurring in rice bran oil and its blend with sunflower oil during repeated frying cycles of dried and moist potato chips were monitored. The parameters assessed were: Colour, Refractive Index, SpecificGravity, Oryzanol Value, Free fatty acid, Iodine Value, Peroxide value, anisidine value, Saponification Value, trans fats and fatty acid composition. No significant changes (p≤0.05) were observed in the refractive index and specific gravity of rice bran oil, sunflower oil and their model blend. The colour of blended oil was lesser than RBO and the intensity of color increased after each frying cycle during the deep fat frying of moistened and dried potato chips. The oryzanol content and iodine value decreased with the frying cycles. The decrease in oryzanol value during the frying operation was more prominent in rice bran oil as compared to the blended oils. The increase in p-anisidine value was more in rice bran oil as compared to blended oil. No significant changes (P<0.05) in the myristic, palmitic and stearic acid composition was observed during the repeated deep fat frying cycles in both the rice bran oil and blended oils samples. The amount of unsaturated fatty acid decreased gradually during repeated deep fat frying cycles in both the oils. The trans fat increased with repeated deep fat frying cycles in both the rice bran and blended oils, when used to fry moistened and dried potato chips. Both the oil samples showed greater formation of trans fatty acids when the moistened potato chips were used during frying.

Overview of trans fatty acids: Biochemistry and health effects

Trans fatty acids (TFA) are unsaturated fatty acids that contain at least one non-conjugated double bond in the trans configuration, resulting in a straighter shape. TFA present in our diet can either be industrially produced and ruminant or natural. The major process contributing to formation of industrial TFA is hydrogenation of vegetable oils. Thermal processes such as edible oil refining and frying also lead to the formation of TFA while, ruminant/natural TFA is formed in the rumen of ruminant animals through bio-hydrogenation. Industrial TFA poses severe effects on our health like cardiovascular problems, insulin resistance, infertility in women, compromised fetal development and cognitive decline. There are strict regulations for limiting/removing the TFA content from food supply across the world. However in India, there is scarcity of data on TFA content in foods and their consumption levels. Given the alarmingly rising trend of diabetes and cardiovascular disease in India, removal of TFA from the food supply along with generating awareness among the masses in this regard is of immense importance.

Effects of antioxidants on heat-induced trans fatty acid formation in triolein and trilinolein

To elucidate the relation between heat-induced cis/ trans isomerisation and thermal oxidative degradation of double bonds in unsaturated lipids, we investigated the effects of several edible antioxidants on these two molecular structural changes of double bonds in triolein ( cis-9, 18:1) and trilinolein ( cis-9, cis-12, 18:2), which were heated at 180 °C. trans Isomerisation and oxidative degradation of each cis double bond in the triacylglycerols during heating were evaluated on the basis of the increase in the amount of trans isomers and decrease in the amount of cis isomers by gas chromatography analysis. The synchronous suppression in trans isomerisation and cis deterioration of double bonds in these triacylglycerols were found by addition of antioxidants, whose inhibitory effects were associated with their kinds and concentrations. When triolein was heated in the presence of antioxidant, suppression of heat-induced trans isomerisation was directly proportional to that of cis deterioration. The results of our analysis suggested that the appropriate addition of antioxidants to edible oils during processing and cooking would facilitate the control of not only thermal oxidative degradation but also heat-induced trans isomerisation of double bonds in unsaturated lipids.

Inhibitory Activity of Natural Occurring Antioxidants on Thiyl Radical-Induced trans-Arachidonic Acid Formation

trans-Fatty acids in humans not only may be obtained exogenously from food intake but also could be generated endogenously in tissues. The endogenous generation of trans-fatty acids, especially in the cell membranes induced by radical stress, is an inevitable source for the living species. Thiyl radicals generated from thiols act as the catalyst for the cis-trans isomerization of fatty acids. Arachidonic acid (5c,8c,11c,14c-20:4) with only two of the four double bonds deriving from linoleic acid in the diet can be used to differentiate the exogenous or endogenous formation of double bonds. The aim of this study is to evaluate the effective compounds in preventing thiyl radical-induced trans-arachidonic acid formation during UV irradiation in vitro. The trans-arachidonic acids were found to be 75% after 30 min UV irradiation of all-cis-arachidonic acid. Myricetin, luteolin, and quercetin had the highest thiyl radical scavenging activities, whereas sesamol, gallic acid, and vitamins A, C, and E had the lowest. The structures of flavonoids with higher thiyl radical scavenging activities were a 3',4'-o-dihydroxyl group in the B ring and a 2,3-double bond combined with a 4-keto group in the C ring. These effective compounds found in the present work may be used as lead compounds for the potential inhibitors in the formation of trans-fatty acids in vivo.

Influence of natural antioxidants on the formation of trans‐fatty‐acid isomers during heat treatment of sunflower oil

AbstractThe intake of foods containing trans fatty acids (TFAs) can have deleterious effects on human health, mainly on the cardiovascular system. Thus, it is important to consider the processes that form TFAs in foods, and the alternatives to minimise their formation. The influence of two added natural antioxidants on TFA formation during heat treatment (120 h at 180°C) of sunflower vegetable oil were examined: rosemary extract (Rosmarinus officinalis L.) (1 g per kg oil) and lutein (0.1 g per kg oil). Changes in FA composition were determined using Ag‐ion SPE and gas–liquid chromatography, with total polar compounds determined using dielectric constant measurements and the index of atherogenicity was calculated. Total TFAs with ≥1 trans double bond increased from 0.91 to 1.71% in control samples; this increase was significantly less with both rosemary extract (1.55%) and lutein (1.43%) additions. Among the individual TFAs, significant increases were seen for C18:1,t‐9, C18:2,t‐9,t‐12 and C18:2,c‐9,t‐12/9‐t,12‐c. Polar compounds also increased, with the highest concentrations in control samples, and significantly less with both rosemary extract and lutein additions. According to results of our study, we can summarize that addition of lutein have greater effect on reduction of TFA formation than rosemary extract.Practical applications: Antioxidants, particularly from plants, are widely used in the food industry. They can provide benefits in food preparation, including improving colour, odour and stability, acting as acid regulators and natural preservatives. They have also become accepted by customers and consumers, and so indirectly they have had effects on consumer perception. Addition of natural antioxidants such as rosemary extract is usually limited by the sensory characteristics of the food, with one study showing that addition of rosemary extract at 1–3 g per kg vegetable oil is recommended. The effects of antioxidants on the formation of TFAs in vegetable oils has not been well studied in the literature. Among the already known benefits, the use of such antioxidants as functional ingredients in lipid technologies might reduce the formation of TFAs during thermal treatment.

Overcoming mass‐transfer limitations in partial hydrogenation of soybean oil using metal‐decorated polymeric membranes

AbstractThe conventional soybean oil hydrogenation process (metal catalyst on solid support particles slurried in oil, H2 bubbled through the oil) is compared with metal‐decorated integral‐asymmetric polyetherimide (PEI) membranes, as far as changes in temperature and pressure are concerned. Using metal‐decorated polymeric membranes, H2 is supplied to the catalytic sites by permeation from the membrane substructure. As opposed to the slurry process, metal‐decorated membranes show only slightly increased trans fatty acid (TFA) formation when the temperature is raised (50–90°C) to accelerate the process. This is likely due to the efficient and to some extent self‐regulating H2 supply directly to the catalytic sites on the membrane skin. The hydrogenation rate and TFA formation of the metal‐decorated membrane process show a minor dependence on pressure. © 2010 American Institute of Chemical Engineers AIChE J, 2011

PENGARUH SUHU DAN LAMA PROSES MENGGORENG (DEEP FRYING) TERHADAP PEMBENTUKAN ASAM LEMAK TRANS

Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Influencing of Deep Frying in Forming of Trans Fatty Acid . Frying process is one of the cooking&rsquo;s techniques using vegetable oil. This process is commonly used in food industry, restaurants, food services, food retail and household scale. This is a laboratory experimental study which performed in laboratory of Public Health Nutrition FKM-UI and Integrated Laboratory IPB, Bogor from December 2005 until March 2006. It was conducted by two (2) type of treatment (used cooking oil ex cassava and meat) with 4 (four) times for each treatment. The objective of this study is to know the influence of frying by using deep frying (frying in high temperature and in a long time) and repeating to trans fatty acid formation in cooking oil. From the result revealed that fatty acid type mostly contained in a fresh cooking oil is oleic acid. Trans fatty acid was formed after second repeating of deep frying and increased in line with the frequent of repeating. Correlation test result had shown that negative association between elaidic acid (trans) and oleic acid (cis) (r = - 0,8; p value = 0.016). In accordance with the beginning of trans fatty acid formation, it would be better to use the cooking oil not more than twice. Keywords: deep frying, trans fatty acid, cooking oil &nbsp;

Partial Hydrogenation of Soybean Oil in a Piston Oscillating Monolith Reactor

The partial hydrogenation of soybean oil was carried out in a novel piston oscillating monolith reactor (POMR). POMR performance was studied under the application of low frequency (0−17.5 Hz) and amplitude (2.5 mm) vibrations at 110 °C and 0.41 MPa H2 using a Pd/Al2O3 monolith catalyst. Results show observed rate improvements of up to 220% for 17.5 Hz, 2.5 mm piston oscillations over low frequency pulsing conditions. For comparison purposes, the reaction was also carried out in a stirred tank reactor using the monolith catalyst. The POMR showed better activity at an equivalent power per unit volume when compared to a stirred tank. With the monolith catalyst, both external and internal mass transfer limitations exist. Using standard diffusion-reaction calculations and measurements over a range of particle sizes it was shown that the vibrations improve external mass transfer rates as well as internal transport within the washcoat. The POMR showed equal or better serial pathway selectivity than a stirred tank, except at the highest frequency, but gave higher trans fatty acid formation.

Hydrogenation of sunflower oil over platinum supported on silica catalysts: Preparation, characterisation and catalytic activity

The effect of varying the Pt content (0.7 - 4.6 wt %) over a novel mesoporous SiO 2 support was investigated for hydrogenation of sunflower oil. The reaction was carried out in a batch reactor at 170 °C, 400 rpm and 3 bar hydrogen pressure. The activity and selectivity of the different catalysts to trans fatty acid formation were compared. The choice of metal precursor affected the catalyst activity, H 2PtCl 6 showed a moderate increase of the Pt activity compared to Pt(AcAc) 2. The presence of chlorine on a supported catalyst is believed to give rise to improved hydrogen spillover, which in turn may improve the hydrogenation activity. For the catalysts prepared using Pt(AcAc) 2, the activity improved with increased Pt loading up to 1.5%Pt, above which no significant increase in activity was observed with additional Pt loading. Additionally, it was found that the activity per exposed metal was greater at lower Pt loadings. The amount of Pt supported on the silica was shown to influence the selectivity to trans C18:1. Increasing the Pt loading from 0.7% to 4.6% correspondingly decreased the metal dispersion and increased the metal particle size. The smaller particles on the 0.7%Pt/SiO 2, 1.5%Pt/SiO 2 and the 2.7%Pt/SiO 2 catalysts presented a lower trans content compared to the 4.6%Pt/SiO 2 catalyst that exhibited larger particles.

Formation of trans fatty acids in edible oils during the frying and heating process

To assess an impact of heated edible oils on intake of trans fat, the formations of trans fatty acids (TFAs) in cooking conditions was estimated by a frying and heating model system. For the frying model, sliced raw potatoes (10% of the frying oil (w/w)) were fried in commercially available canola oil at 160, 180 and 200 °C, and the 10 frying cycles were performed. The TFAs contained both in fried potatoes and in frying oils were measured by gas chromatography (GC). Lipids content of raw potatoes was about 0.1% (w/w) and TFAs in the raw potatoes were negligible. On the other hand, fried potatoes contained lipids at the level of 8.8%–9.2% and their fatty acid composition was mostly in correspondence with that of the frying oil. The TFAs amount of potatoes fried by the tenth frying operation was at the level of 0.99–1.05 g/100 g lipids. When 100 g potatoes fried in this process were consumed, the TFAs intake was estimated at less than 0.1 g. After 10 frying operations, TFAs content, acid values and peroxide values of the frying oils were measured and compared with those of corresponding heated canola oils without food. The amounts of trans 18:1 FAs contained both in the frying oil and in heated oil were less than the quantitative limit (0.047 g/100 g oil). The increases of trans 18:2 FAs and trans 18:3 FAs of the used frying oil were 0.02 g/100 and 0.05 g/100 g, respectively, compared with those of the fresh oil. trans 18:2 FAs accumulation in the heated oil was slightly less than that in the frying oil. To elucidate TFAs accumulation in various edible oils during cooking, six kinds of commercially available edible vegetable oils were heated to 180 °C in glass test tubes. Small changes in TFAs amounts were observed after four hours heating. These results suggested that an ordinary frying process using unhydrogenated edible oils has little impact on TFAs intake from edible oils.

Activity and Selectivity of Nanostructured Sulfur-Doped Pd/SBA-15 Catalyst for Vegetable Oil Hardening

Sunflower and canola oils were hardened over a novel sulfur-promoted Pd catalyst. The formulated catalyst comprised of 0.7 wt % palladium nanoparticles promoted with 0.3 wt % sulfur highly dispersed on mesoporous silica SBA-15 (0.7% Pd−0.3% S/SBA-15). The effect of temperature (80−130 °C) and H2 pressure (3.6−9.3 atm) on the activity, selectivity, and trans (TFA) and saturated (SFA) fatty acids formation were studied for both oils. Under similar temperature and H2-pressure conditions, sunflower and canola oils exhibited different reactivities toward hydrogenation. For both oils, the activity of the catalyst increased with the temperature and with the pressure. However, increasing the temperature raised the levels of trans C18:1 especially at low hydrogen pressure. Partial hydrogenation of both oils from initial iodine (IVo) values of 120−130 to a final value of 90 with the sulfur-doped Pd catalyst yielded modified oils with a low TFA level (6%) and also controlled the formation of SFA (∼7%) under mild tem...

Effects of Mixing Canola and Palm Oils with Sunflower Oil on the Formation of Trans Fatty Acids during Frying

GLC analysis was conducted to indicate the formation of trans- C18 fatty acids of sunflower, canola and palm oils during frying. Blends of sunflower oil and palm oil or canola oil were obtained by mixing sunflower oil with palm or canola oils at the volume ratios of 60: 40, 40: 60 and 20: 80 (v/v), then heated at 180?C ± 5?C for 5, 10, 15 and 20 h in the atmospheric oxygen. GLC results demonstrate that the formation of trans C18-fatty acids was generally dependent upon the frying time and oil mixing ratios. Furthermore, mixing sunflower oil with oils rich in monounsaturated fatty acids (palm or canola oils) lowered the formation of trans-C18 fatty acids during frying.

Formation of Trans Fatty Acids in Ground Beef and Frankfurters due to Irradiation

This study was conducted to investigate possible formation of trans fatty acids due to irradiation of ground beef and frankfurters. Ground beef and frankfurter samples were irradiated at doses of 0, 1, and 5 kGy at 4 degrees C, and stored at 4 degrees C for 7 d (ground beef) or 3 mo (frankfurters). After irradiation and storage of the samples, trans fatty acids along with other fatty acids were analyzed using a modification of AOAC method 996.01. The results showed that 1 kGy irradiation did not induce any change in trans fatty acid content. However, 5 kGy irradiation caused a small but statistically significant (P < 0.01) increase in the dominant trans fatty acid, C18:1 trans, which increased from 3.99% (of total fatty acid) for the nonirradiated ground beef to 4.05% for the 5 kGy sample, and from 1.21% for the nonirradiated frankfurter to 1.28% for the 5 kGy sample. Irradiation had no apparent effect on C16:1 and C18:2 trans fatty acids. In addition, irradiation slightly decreased the relative amount of poly-unsaturated fatty acid of ground beef and frankfurters, particularly after storage. Compared to variations in trans fatty acid content and fatty acid composition occurring naturally in meat and meat products, the changes due to irradiation were negligible.

BRIEFING PAPER: Culinary oils and their health effects

Summary Introduction Worldwide production, processing and consumption Production, storage and processing Culinary oils, nutrition and health Contribution of culinary oils to nutrient intakes in the UK diet The culinary oils Developments in culinary oils Culinary oils in a healthy, balanced diet ConclusionsAcknowledgementsReferencesSummaryVegetable oils are mainly produced from oilseeds (e.g. rapeseed and sunflower seed) as well as from legumes (e.g. peanut and soybean), nuts (e.g. walnut and almond) and the flesh of some fruits (e.g. olives). Vegetable oils are pressed from the plants and are then processed and refined to produce high‐quality oils suitable for use as an ingredient in recipes, for frying, in salad dressings and in the production of margarines and spreads.There has been substantial growth in the oilseeds markets over the past 30 years. This was initially driven by health concerns but, more recently, has been because of the interest in biofuels and the changing market. In 2008, the four main types of vegetable oil that dominated the world market (in terms of the quantities produced) were palm oil, soybean oil, rapeseed oil and sunflower seed oil. In the UK, the only oilseed crops harvested are rapeseed, hempseed and linseed/flaxseed. However, there are substantial imports of groundnuts, soybeans, sunflowers and palm kernels that are processed in the UK resulting in the production of a variety of different oils in the UK.Vegetable oils mainly comprise triacylglycerides. The main nutrient they provide is fat. The only other nutrient that is present in appreciable amounts is vitamin E (tocopherols and tocotrienols). Vegetable oils are also the main source of natural plant sterols in the diet and contain minor components, such as squalene and sphingolipids, all of which may provide a range of health benefits.The fatty acid composition of plant oils varies, and all plant oils are composed of a mixture of different fatty acids, in different proportions. Most culinary oils tend to be high in either monounsaturates or polyunsaturates, with the exception of palm kernel and coconut oils which are high in saturates. Categorising fats as ‘saturated fats’, ‘monounsaturated fats’ or ‘polyunsaturated fats’ (based on the predominant fatty acid) may be helpful for consumer understanding. However, this is an oversimplification of the actual situation.The constituent fatty acids of each culinary oil are primarily responsible for the functionality of the oil, along with the minor components. The properties of the oil can be modified through technical processes including hydrogenation, fractionation and interesterification. The processes used to modify the properties of oils have become a widely debated topic. Hydrogenation was a commonly used process to increase hardness and to stabilise fats without having to increase saturates to any great extent. However, as partial hydrogenation results in the formation of trans fatty acids, its use in the UK for consumer products has now virtually ceased. Some food manufacturers have been using interesterification to ensure that the oil has functional properties and the desired organoleptic qualities, without the formation of trans fatty acids. Alternatively, manufacturers have looked for new oils with more favourable fatty acid profiles. This has been made possible through plant breeding programmes using both conventional techniques and genetic modification and will have an important impact on the fatty acid profile of the UK diet in the future.However, overall there is little evidence to suggest that one vegetable oil should be promoted over any other oil on the basis of additional health effects as there are few good quality trials that have adequately compared the health outcomes of individuals consuming different oils. Indeed, because of the use of a variety of different vegetable‐based oils in food manufacturing processes, most people are consuming a wide variety of different oils each day. Instead, the choice of the oil often depends on the functionality of the oil for a particular food application, or on taste, personal preference or cost. The most important message for consumers to understand is that all oils, regardless of whether they contain ‘good’ or ‘bad’ fats, are almost 100% fat and that the oils themselves, as well as products manufactured from them, should only ever be included in the diet in moderate quantities.

Mutations in a Δ9–Stearoyl‐ACP‐Desaturase Gene Are Associated with Enhanced Stearic Acid Levels in Soybean Seeds

Stearic acid (18:0) is typically a minor component of soybean [Glycine max (L.) Merr.] oil, accounting for only 2 to 4% of the total fatty acid content. Increasing stearic acid levels of soybean oil would lead to enhanced oxidative stability, potentially reducing the need for hydrogenation, a process leading to the formation of undesirable trans fatty acids. Although mutagenesis strategies have been successful in developing soybean germplasm with elevated 18:0 levels in the seed oil, the specific gene mutations responsible for this phenotype were not known. We report a newly identified soybean gene, designated SACPD‐C, that encodes a unique isoform of Δ9–stearoyl‐ACP‐desaturase, the enzyme responsible for converting stearic acid to oleic acid (18:1). High levels of SACPD‐C transcript were only detected in developing seed tissue, suggesting that the encoded desaturase functions to enhance oleic acid biosynthetic capacity as the immature seed is actively engaged in triacylglycerol production and storage. The participation of SACPD‐C in storage triacylglycerol synthesis is further supported by the observation of mutations in this gene in two independent sources of elevated 18:0 soybean germplasm, A6 (30% 18:0) and FAM94‐41 (9% 18:0). A molecular marker diagnostic for the FAM94‐41 SACPD‐C gene mutation strictly associates with the elevated 18:0 phenotype in a segregating population, and could thus serve as a useful tool in the development of cultivars with oils possessing enhanced oxidative stability.

Trans fatty acid content and positional distribution in refined and heated rice bran oil

AbstractThe objective of this study was to evaluate the impact of the refining process and of heating at frying temperature (180 °C, 8 h) on the content of trans fatty acids and their positional distribution in sn‐positions of triacylglycerols (TAG) of rice bran oil. Tr‐18:2 was an artifact specific to the deodorization step, which additionally changed its distribution at the 2‐MAG and 1,3‐DAG positions. No correlation between the formation of polymer TAG and trans fatty acids could be observed.

Effect of reactor type on trans fatty acid and stearate formation in fat hydrogenation in SCF solvent

Hydrogenation of vegetable fats is an important biomolecule modification process, traditionally carried out in a slurry reactor at low pressure (2–6 bar). Here, the hydrogenation of sunflower oil in supercritical propane and dimethyl ether catalysed by Pd (supported on activated carbon or alumina) is studied. One-dimensional simulation models for plug flow and mixed flow reactors, as well as two-dimensional dispersed plug flow reactor models, were developed for the case of isothermal and adiabatic operation. The hydrogenation of sunflower oil is considered as a reaction network based on linoleate, oleate ( cis C18:1), elaidate ( trans C18:1) and stearate triesters. Since trans fatty C18:1 ester and stearate formation is not desired, the question arises as to which reactor type is best to achieve a low elaidate content. Depending on the final allowed stearate content, different mixed and plug flow reactor models can be applied. However, for a fixed stearate formation rate, the mixed reactor gives a lower trans content than the plug flow reactor in most cases. Also, low temperature operation results in better oleate/stearate selectivity. Two-dimensional tubular reactor dispersed simulation does not give further insight into the problem. The use of Multiphysics (finite element method) for solving the dispersed plug flow model provides a way to simulate CSTR reactor behaviour. In our case, both heat and mass Péclet numbers of 10 −4 or less are sufficient to describe well-mixed reactor behaviour using the 2D mass and heat transfer pseudo-homogeneous model with radial and axial effects, with parameter values available for SCF. The models can be used for planning reaction operations in SCF as solvents intended for low trans fatty acid.

Nickel–boron alloy catalysts reduce the formation of Trans fatty acids in hydrogenated soybean oil

Soybean oil was hydrogenated by a group of amorphous alloy nanocatalysts of nickel and boron (Ni–B). The Ni–B alloy catalysts showed activities dependent on synthesis conditions. The trans-fat contents in products hydrogenated by one Ni–B catalyst were approximately half of those when a commercial nickel catalyst was used. The Ni–B catalyst had a lower selectivity towards formation of trans-fatty acids but a higher selectivity towards formation of stearic acid than the commercial nickel catalyst. The increases in trans-fatty acids correlated linearly with the increases in C18:1 (oleic and elaidic acids) for nickel-containing catalysts. The incorporation of boron in nickel-containing catalysts increased the selectivity ratio (for forming stearic acid) but did not change the linolenic selectivity. Because of the simplicity to synthesize amorphous catalysts, this work may lead to future development of novel alloy nanocatalysts to synergistically reduce the formation of both trans- and saturated fatty acids in hydrogenated products.

Low Trans and Saturated Vegetable Oil Hydrogenation over Nanostructured Pd/Silica Catalysts: Process Parameters and Mass-Transfer Features Effects

Sunflower and canola oils were hydrogenated over a novel Pd catalyst and a commercial N catalyst. The Pd catalyst consisted of palladium nanoparticles highly dispersed on mesostructured silica material. The effect of temperature (80−130 °C) and H2 pressure (3.6−9.3 atm) on the activity, selectivity, and trans (TFA) and saturated (SFA) fatty acids formation were studied for both oils and types of catalysts. It was found that the reaction temperature and the hydrogen pressure increased the activity of both catalysts and controlled the solubility of hydrogen and the cis/trans isomerization. The Pd catalyst exhibited a greater selectivity toward the formation of monoene in comparison to the commercial Ni catalyst. Partial hydrogenation of both oils from initial iodine (IVo) value of 120−130 to a final IV of 90 with the nanostructured Pd catalyst using a conventional stirred reactor equipped with a surface aeration turbine-type impeller yielded modified oils with low TFA level (7−10%) and also controlled the formation SFA (∼7%) under mild process conditions. Further reduction of TFA level was achieved when the hydrogenation of vegetable oils over Pd catalyst was carried out with a reactor equipped with a gas-inducing sparger-type impeller having enhanced mass-transfer features. Very low TFA (<5%) and SFA (3%) levels were obtained at a final IV value of 92.