Production Of Structured Lipids Research Articles

Synthesis of structured lipid with balanced omega-3: Omega-6 ratio by lipase-catalyzed acidolysis reaction: Optimization of reaction using response surface methodology

The present study deals with the production of structured lipid containing omega-3 and omega-6 fatty acids in the ratio of 1:1 by incorporating omega-3 fatty acids (α-linolenic acid) from linseed oil into groundnut oil using lipase (Lipozyme IM from Rhizomucor miehei) catalyzed acidolysis reaction in hexane. The reaction conditions were optimized by response surface methodology with a four-variable five-level central composite rotatable experimental design. The influence of four independent parameters, namely ratio of fatty acid concentrate from linseed to groundnut oil (0.66–1.98, w/w), reaction temperature (30–60 °C), enzyme concentration (1–5%) and reaction time (2–54 h) on omega-3 fatty acids incorporation into groundnut oil were optimized. Optimal conditions for the structured lipid containing omega-3 to omega-6 fatty acids in the ratio of 1:1 were determined to be; enzyme concentration 3.75% (w/w), temperature 37.5 °C, incubation time 30.81 h and ratio of free fatty acid concentrate from linseed oil to groundnut oil 1.16 (w/w).

Lipase‐assisted acidolysis of high‐laurate canola oil with eicosapentaenoic acid

AbstractThe production of structured lipids via acidolysis of high‐laurate canola oil (Laurical 15) with EPA in hexane was carried out using lipase from Pseudomonas sp. The optimal reaction conditions used 4% lipase, at a mole ratio of oil to EPA of 1∶3 at 45°C over 36 h. The positional distribution of FA on the glycerol backbone of unmodified oil indicated that lauric acid was mainly located at the sn‐1,3 positions. Stereospecific analysis of the oil modified with EPA showed that lauric acid remained mostly esterified to the sn‐1,3 positions of the TAG molecules and that EPA was also primarily in the sn‐1,3 positions of the TAG molecules. Thus, the resultant structured lipids may have optimal value for use in applications where quick energy release and EPA supplementation are required.

Effects of antioxidants on the lipase‐catalyzed acidolysis during production of structured lipids

AbstractIn the production process of structured lipids, the influence of the addition of antioxidants before enzymatic acidolysis was investigated. Eight different antioxidants were screened: butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, ascorbyl palmitate, citric acid, EDTA, a tocopherol blend and lecithin. As substrates, oils with different degrees of unsaturation (rapeseed, safflower or fish oil) as well as caprylic and capric acids were used. Enzyme activity (measured as percent incorporation of caprylic/capric acid into the oils) was not significantly influenced by the addition of antioxidants, neither in a batch process nor in a packed‐bed reactor operation. α‐Tocopherol concentrations remained stable for those mixtures where tocopherols were added. Primary oxidation products (measured as peroxide values) were reduced after acidolysis in the packed‐bed reactor, likely due to the adsorption in the enzyme bed. The study shows that the addition of antioxidants before enzymatic reactions has no negative effects on the reaction progress. None of the antioxidants chosen had a significant positive effect on either the reaction process or the oxidative status of the structured lipid produced.

Modification of Oils and Fats to Produce Structured Lipids

Awareness regarding the harmful effects of excessive oils and fats intake is universal. Consequently, health conscious individuals are modifying their dietary habits and eating less fat , as high fat intake specially saturated fat is associated with increased risk for obesity, high blood cholesterol, coronary heart disease, cancer, and arteriosclerosis. Although oils and fats are not only the concentrated source of energy but also the source of essential fatty acids (EFA). Taking into account the drawbacks and benefits of oils and fats, the production of Structured Lipids (SLs) containing especial fatty acids has been now a days attracting more and more attention.

Production of structured lipids by acidolysis of an EPA-enriched fish oil and caprylic acid in a packed bed reactor: analysis of three different operation modes.

Structured triacylglycerols (ST) enriched in eicosapentaenoic acid (EPA) in position 2 of the triacylglycerol (TAG) backbone were synthesized by acidolysis of a commercially available EPA-rich oil (EPAX4510, 40% EPA) and caprylic acid (CA), catalyzed by the 1,3-specific immobilized lipase Lipozyme IM. The reaction was carried out in a packed bed reactor (PBR) operating in two ways: (1) by recirculating the reaction mixture from the exit of the bed to the substrate reservoir (discontinuous mode) and (2) in continuous mode, directing the product mixture leaving the PBR to a product reservoir. By operating in these two ways and using a simple kinetic model, representative values for the apparent kinetic constants (kX) for each fatty acid (native, Li or odd, M) were obtained. The kinetic model assumes that the rate of incorporation of a fatty acid into TAG per amount of enzyme, rX (mole/(h g lipase)) is proportional to the extent of the deviation from the equilibrium for each fatty acid (i.e., the difference of concentration between the fatty acid in the triacylglycerol and the concentration of the same fatty acid in the triacylglycerol once the equilibrium of the acidolysis reaction is reached). The model allows comparing the two operating modes through the processing intensity, defined as mLt/(V[TG]0) and mL/(q[TG]0), for the discontinuous and continuous operation modes, respectively. In discontinuous mode, ST with 59.5% CA and 9.6% EPA were obtained. In contrast, a ST with 51% CA and 19.6% EPA were obtained when using the continuous operation mode. To enhance the CA incorporation when operating in continuous mode, a two-step acidolysis reaction was performed (third operation mode). This continuous two-step process yields a ST with a 64% CA and a 15% EPA. Finally, after purifying the above ST in a preparative silica gel column, impregnated with boric acid, a ST with 66.9% CA and 19.6% EPA was obtained. The analysis by reverse phase and Ag+ liquid chromatography of the EPA-enriched ST demonstrated that the CA was placed in positions 1 and 3 and the EPA was occupying position 2 of the final ST.

Production of structured lipids by lipase‐catalyzed acidolysis in supercritical carbon dioxide: Effect on acyl migration

AbstractStructured lipids were synthesized by the acidolysis of corn oil by caprylic acid in supercritical carbon dioxide (SCCO2) with Lipozyme RM IM from Rhizomucor miehei. The effects of pressure and temperature on the reaction were studied. To compare the degrees of acyl migration in the SCCO2 and solvent‐free reaction systems, the effects of reaction time on the degree of acyl migration were also studied. The highest mole percentage incorporation of caprylic acid (62.2 mol%) occurred at 24.13 MPa in SCCO2. The overall incorporation of caprylic acid in the SCCO2 system remained higher than that in the solvent‐free system at every temperature tested. This trend was observed more clearly at lower temperatures (35–55°C) than at higher temperatures (65–75°C). Acyl migration with both reaction systems was low, with a negligible difference between them up to 12 h, after which the degree of acyl migration in the solvent‐free system increased rapidly with time up to 24 h compared with the SCCO2 system.

Consistencia de lípidos estructurados a partir de aceite de pescado y grasa de palmiste

Through interesterification of oils and fats is possible to obtain structured lipids (SL), which are considered functional foods, due their potential effects on the prevention of diseases. For this reason, there is great interest in the production of SL. The objective of this paper was to obtain structured lipids from chemical interesterification from palm kernel fat and fish oil and to analyse the interactions that occur in the binary mixtures of these lipids. Six samples consisting of two individual samples and four binary mixtures were studied. The samples were analyzed for fatty acid composition and consistency at the range temperature from 5 to 25oC. A mathematical model of multiple regression of the quadratic type was applied. The results showed that the interactions between the two components were significant. The consistency depended on the palm kernel fat and on the binary interactions between palm kernel fat and fish oil. The negative coefficients to the consistency showed an antagonic effect which is characteristic of eutectic interactions between fats.

Structured Lipids-Novel Fats with Medical, Nutraceutical, and Food Applications.

Generally, structured lipids (SLs) are triacylglycerols (TAGs) that have been modified to change the fatty acid composition and/or their positional distribution in glycerol backbone by chemically and/or enzymatically catalyzed reactions and/or genetic engineering. More specifically, SLs are modified TAGs with improved nutritional or functional properties. SLs provide an effective means for producing tailor-made lipids with desired physical characteristics, chemical properties, and/or nutritional benefits. The production, commercialization outlook, medical, and food applications of SLs are reviewed here. Physical property measurements for SL in food systems and future research needs for increased industrial acceptance are also included in this review.

Production of structured lipids in a packed‐bed reactor with thermomyces lanuginosa lipase

AbstractLipase‐catalyzed interesterification between fish oil and medium‐chain TAG has been investigated in a packedbed reactor with a commercially immobilized enzyme. The enzyme, a Thermomyces lanuginosa lipase immobilized on silica by granulation (lipozyme TL IM; Novozymes A/S, Bagsvaerd, Denmark), has recently been developed for fat modification. This study focuses on the new characteristics of the lipase in a packed‐bed reactor when applied to interesterification of TAG. The degree of reaction was strongly related to the flow rate (residence time) and temperature, whereas formation of hydrolysis by‐products (DAG and FFA) were only slightly affected by reaction conditions. The degree of reaction reached equilibrium at 30–40 min residence time, and the most suitable temperature was 60°C or higher with respect to the maximal degree of reaction. The lipase was stable in a 2‐wk continuous operation without adjustment of water content or activity of the column and the substrate mixture.

Lipase-catalyzed acidolysis of olive oil and caprylic acid in a bench-scale packed bed bioreactor

Lipase-catalyzed acidolysis of olive oil and caprylic acid was performed in a bench-scale packed bed bioreactor to produce structured lipids (SL). A 1,3-specific lipase, IM 60 from Rhizomucor miehei was used as the biocatalyst. Reaction products were analyzed by reversed phase high-performance liquid chromatography, with an evaporative light scattering detector. Olive oil is characterized by four major clusters of triacylglycerol species with equivalent carbon number (ECN), C44, C46, C48, and C50. Three monosubstituted products and two disubstituted products were detected after the reaction. Monosubstituted products had ECN of C36, C38, and C40, and disubstituted products had ECN of C30 and C32. The effect of solvent, temperature, substrate mol ratio, and flow rate/residence time were studied. Optimal solvent-free production of SL was obtained at a substrate flow rate of 1 ml/min, residence time 2.7 h, temperature 60°C, and mol ratio 1:5 (olive oil/caprylic acid). Fatty acid distribution at the sn-2 position of olive oil was determined by pancreatic lipase hydrolysis as 74.8% oleic acid and 25.2% linoleic acid. SL produced at optimal conditions had 7.2% caprylic acid, 69.6% oleic acid, 21.7% linoleic acid and 1.5% palmitic acid at the sn-2 position.

Production of structured lipids by lipase‐catalyzed interesterification in a flat membrane reactor

AbstractThe application of membrane technology to the enzymatic production of specific structured lipids has been investigated in this work. Membrane screening was carried out in a membrane diffusion cell. Twenty‐six flat membranes of different materials were tested using rapeseed oil and capric acid. The suitable membranes were selected in terms of higher fatty acid and lower rapeseed oil permeation rates. The stability of membranes and the effect of fatly acid chain length on effluent fluxes were also investigated. Reaction experiments were carried out in a membrane reactor between medium‐chain triacylglycerols and n−3 polyunsaturated fatty acids (PUFA) from fish oil. Lipozyme IM was used as the biocatalyst. The incorporation of PUFA into medium‐chain triacylglycerols was increased by about 15% in a PUFA 90‐h reaction by simultaneous separation of the released medium‐chain fatty acids, compared to no separation under the same reaction conditions. It has thus clearly been demonstrated that membrane‐assisted separation improved the incorporation of acyl donors into oils beyond the reaction equilibrium defined by the original substrate concentration.

Production of structured lipids by lipase-catalysed interesterification in an ultrafiltration membrane reactor

The application of membranes to the enzymatic production of structured lipids has been investigated using an ultrafiltration membrane reactor for a reaction between medium chain triacylglycerols (MCT) and n-3 polyunsaturated fatty acids from fish oil. Lipozyme IM was used as the biocatalyst. The incorporation of polyunsaturated fatty acids into MCT was increased by about 15% over 80 h by simultaneous separation of the released medium chain fatty acids compared to control.

Production of structured lipids by lipase-catalyzed interesterification in a packed bed reactor: effect of reaction parameters on the level of diacylglycerols in the products

The 1,3-specificity of a lipase was utilized in lipase-catalyzed interesterification to produce specific structured lipids containing long-chain polyunsaturated fatty acids at the sn-2 position and medium-chain fatty acids (MCFAs) at the primary position in a packed-bed reactor. Diacylglycerols (DAGs) are important intermediate products in the production of structured lipids, both with regard to the yields of the products and the content of the by-products, but the levels of DAGs produced in lipase-catalyzed interesterification in a continuous process are not well-known. We examined the effects of the following interesterification parameters on the level of DAGs: reaction temperature, residence time, substrate ratio, and water content. Reaction temperature was the most critical factor, with elevated reactor temperatures (particular those above 60 °C) resulting in a considerable increase in the DAG content of the products. Longer residence times increased the level of DAGs in the products, and favoured the formation of 1,3-DAGs from 1,2-DAGs by acyl migration. Increasing the molar ratio between MCFAs and oil, as well as increasing the water content in the reacting substrate mixture affected the DAG content only slightly. The DAG content in the interesterification products had positive correlation with the migration of MCFAs, implying that a high level of DAGs is an indicator for partial acylglycerols and positional isomers, both are impurities in the products. On the other hand, the content of DAGs correlated positively with the incorporation of MCFAs, suggesting that the DAGs are also important for the production of the structured lipids. Under optimized conditions (temperature, 60°C; water, 0.03%; residence time, 4 h; substrate ratio, 6:1), the level of DAGs produced in the packed-bed reactor was less than 4%, and the incorporation and migration of MCFAs were 47% and 1%, respectively.

Lipid Modification Strategies in the Production of Nutritionally Functional Fats and Oils

Rapid improvements in the understanding of the nutritional requirements of both infants and adults has led to new developments in the modification of fats and oils. Specific targets include the improvement in growth and development of infants, treatment of disease in adults, and disease prevention.Efforts have been focussed on the production of structured lipids using medium-chain acids and long-chain polyunsaturated fatty acids (PUFAs), as well as the concentration of long-chain PUFAs from new and existing sources. Short- and medium-chain fatty acids are metabolized differently than long-chain fatty acids and have been used as a source of rapid energy for preterm infants and patients with fat malabsorption-related diseases. Long-chain PUFAs, specifically docosahexaenoic acid and arachidonic acid, are important both in the growth and development of infants, while n-3 PUFAs have been associated with reduced risk of cardiovascular disease in adults. Based on the requirements for individual fat components by different segments of the population, including infants, adults, and patients, ideal fats can be formulated to meet their needs. By using specific novel fat sources and lipid modification techniques, the concentrations of medium-chain, long-chain saturated, and long-chain polyunsaturated fatty acids as well as cholesterol can be varied to meet the individual needs of each of these groups.While genetic modification of oilseeds and other novel sources of specific lipid components are still being developed, chemical and lipase-catalyzed interesterification reactions have moved to the forefront of lipid modification technology. Fractionation of fats and oils to provide fractions with different nutritional properties has potential, but little work has been performed on the nutritional applications of this method. The choice of suitable lipid modification technologies will depend on the target lipid structure, production costs, and consumer demand. A combination of some or all of the present lipid modification techniques may be required for this purpose.

Production of structured lipids containing essential fatty acids by immobilizedRhizopus delemar lipase

AbstractAn attempt was made to produce structured lipids containing essential fatty acid by acidolysis with 1,3‐positional specificRhizopus delemar lipase. The lipase was immobilized on a ceramic carrier by coprecipitation with acetone and then was activated by shaking for 2 d at 30°C in a mixture of 5 g safflower or linseed oil, 10 g caprylic acid, 0.3 g water and 0.6 g of the immobilized enzyme. The activated enzyme was transferred into the same amount of oil/caprylic acid mixture without water, and the mixture was shaken under the same conditions as for the activation. By this reaction, 45–50 mol% of the fatty acids in oils were exchanged for caprylic acid, and the immobilized enzyme could be reused 45 and 55 times for safflower and linseed oils, respectively, without any significant loss of activity. The triglycerides were extracted withn‐hexane after the acidolysis and then were allowed to react again with caprylic acid under the same conditions as mentioned above. When acidolysis was repeated three times with safflower oil as a starting material, the only products obtained were 1,3‐capryloyl‐2‐linoleoylglycerol and 1,3‐capryloyl‐2‐oleoyl‐glycerol, with a ratio of 86∶14 (w/w). Equally, the products from linseed oil were 1,3‐capryloyl‐2‐α‐linolenoyl‐glycerol, 1,3‐caprylol‐2‐linoleoyl‐glycerol, and 1,3‐capryloyl‐2‐oleoly‐glycerol (60∶22∶18, w/w/w). All fatty acids at the 1,3‐positions in the original oils were exchanged for caprylic acid by the repeated acidolyses, and the positional specificity ofRhizopus lipase was also confirmed to be strict.

Immobilized lipase‐catalyzed production of structured lipids with eicosapentaenoic acid at specific positions

AbstractStructured lipids (SL) were synthesized by the interesterification reaction between medium‐chain triacylglycerols and eicosapentaenoic acid (EPA) ethyl ester. The products were partially purified, and the fatty acid at thesn‐2 position was determined after pancreatic lipase‐catalyzed hydrolysis. The effect of additives (water and glycerol) on the rate of reaction was also investigated. Mol% EPA incorporated into the triacylglycerols was increased by adding water when trilaurin and tricaprylin were the substrates and IM 60 was the biocatalyst. With SP 435, EPA incorporation was always less with additional water than without water. The addition of glycerol (0.005 g or 0.01 g) improved interesterification catalyzed by IM 60 to some degree, but an excess amount (0.02 g) inhibited the reaction. The reaction with glycerol showed no significant difference with SP 435. After scale‐up and fractionation by column chromatography, we could recover approximately 0.3–0.4 g of product/g of reaction products. After hydrolysis by pancreatic lipase, we can conclude that IM 60 has a high specificity forsn‐1,3 positions. With SP 435 lipase, 34.8–39.3 mol% of EPA was found at thesn‐2 position of the recovered SL.

Production of structured lipid containing docosahexaenoic and caprylic acids using immobilized Rhizopus delemar lipase

Triglycerides with medium-chain fatty acids at the 1- and 3-positions and functional fatty acids at the 2-position are referred to as structured lipids. An attempt was made to produce a structured lipid containing docosahexaenoic and caprylic acids using 1,3-positional specific Rhizopus delemar lipase, which was immobilized on a ceramic carrier by coprecipitation with acetone. When a reaction mixture containing 5 g tuna oil and 10 g caprylic acid, 0.6 g immobilized lipase, and 0.3 g water was incubated at 30°C for 2 d with shaking, acidolysis proceeded effectively but hydrolysis occurred simultaneously. This hydrolysis could be repressed by omitting water from the subsequent reaction mixture. The immobilized lipase could be reused 14 times without any significant loss of activity, and approximately 65% of the fatty acids at the 1- and 3-positions in the tuna oil were exchanged for caprylic acid. All the triglyceride products contained one or two caprylic acid molecule(s). Docosahexaenoic acid bound at the 1(3)-position in tuna oil was not exchanged because of the low activity of the R. delemar lipase on it.

Functional Characteristics and Nontraditional Applications of Milk Lipid Components in Food and Nonfood Systems

Milk fat can be modified to improve its functionality and expand its usage for traditional and nontraditional applications. The triglyceride, diglyceride, monoglyceride, and individual fatty acid components of milk fat determine functionality. Milk fat functionally is expressed through crystallization and melting behaviors, surface-active properties, and nutritional properties. Methods that are available to modify the functional properties of milk fat include fractionation by melt crystallization and supercritical fluid extraction, blending, texturization, interesterification, and glycerolysis. The selection of modification procedures is often driven by the requirement of the application.Modification of selected functionalities can expand the opportunities for milk fat as nontraditional ingredients in traditional applications, such as the use of milk fat fractions in chocolate and bakery products. New applications include the use of intact milk fat and milk fat fractions in the production of structured lipids, sucrose polyesters, edible films, emulsifiers, and cosmetics. Other nontraditional functionality associated with milk lipid components includes the antioxidant and anticarcinogenic properties of conjugated linoleic acid and the antimicrobial properties of lauric acid.