Stearidonic Acid Content Research Articles

Fatty acid profiles of seeds from different Ribes species

Fatty acid composition of different cultivars of blackcurrant (Ribes nigrum L.), redcurrant (Ribes rubrum L.), gooseberry (Ribes uva-crispa L.) and jostaberry (Ribes nidrigolaria Bauer) was studied. These seeds contained from 17.8% to 22.4% of oil. The major fatty acid (FA) determined in these Ribes species was linoleic acid and significant differences were determined between the seeds of these Ribes species for all fatty acids analysed, except for stearic acid. Jostaberries had the lowest n-6/n-3 ratio, Index of Atherogenicity, Index of Thrombogenicity and the highest α-linolenic and stearidonic acid contents. Blackcurrants had the highest γ-linolenic acid content, followed by gooseberries. With their favourable FA composition, seeds of these Ribes species represent an interesting new source of essential FA that can be used as a supplement in everyday nutrition.

Use of <em>Echium</em> oil fatty acids and tricaprylin as substrates of enzymatic interesterification for the production of structured lipids

Structured lipids (SLs) were produced from the free fatty acids of Echium oil and tricaprylin by enzymatic acidolysis reactions. Lipozyme® RM IM, immobilized sn-1,3 specific lipase was used in the enzymatic reactions. In order to optimize the incorporation of stearidonic acid (SDA), three factors were chosen [Reaction temperature (50-60 ºC), reaction time (6-12 hour) and substrate molar ratio (3-6 mol/mol (total free fatty acids/tricaprylin)] for the application of response surface methodology (RSM) using a central composite circumscribed design (CCC) with five levels. The optimum temperature, time and substrate molar ratio obtained from the models were 60 ºC; 6 h, 6 mol/mol, respectively. Furthermore, SLs with 6.2% SDA content at sn-2 position were produced by scaling up the process. SL was obtained with nearly 78-79% of long-chain fatty acids at the sn-2 position. According to the melting profile analysis, the melting peaks of tricaprylin and Echium oil were sharper and narrower while the SL had more broadened peaks.

Preparation of phytosteryl ester and simultaneous enrichment of stearidonic acid via lipase-catalyzed esterification

Abstract The simultaneous synthesis of a phytosteryl ester and enrichment of stearidonic acid (SDA) were performed via a one-step lipase-catalyzed esterification of fatty acids from Ahiflower™ seed oil with phytosterol. A commercial lipase (Lipase OF) from Candida rugosa was employed as a biocatalyst. Three solvents were screened and cyclohexane was selected as a suitable reaction medium. The effects of enzyme loading, temperature, and solvent amount were investigated. The conversion as well as the SDA content were significantly improved by adding molecular sieves after 1 h of reaction. The optimum conditions were the enzyme loading of 10% (based on the total substrate weight), the temperature of 30 °C, and the solvent amount of 4 mL (based on a substrate weight of 2 g), respectively. The maximum conversion and SDA content in the residual fatty acid were 81 mol% and 58 mol%, respectively, under the optimum conditions. The SDA content increased a 3.4-fold from 17 mol% in Ahiflower™ seed oil to 58 mol%.

Enhancement of nutritionally significant constituents of black currant seeds by chemical elicitor application

Black currant seeds are obtained as a residue during juice production. Black currant seed oil contains high amounts of nutritionally desirable constituents such as γ-linolenic acid (GLA), α-linolenic acid (ALA) and stearidonic acid (SA), as well as certain phenolic acids, which act as natural antioxidants. Fatty acids and phenolic acids of seeds from black currant cultivars after elicitation with methyl jasmonate (MJ) were examined. GLA contents around 25% with respect to total fatty acid content were measured in seeds after pre-harvest treatment of black currants with 0.02mM MJ in 0.05% Tween-20. High GLA samples also exhibited high SA content (higher than 10% with respect to total fatty acid content); however, ALA dropped (from 16% to 10%). High GLA content seeds also showed increased contents of gallic, caffeic, p-coumaric and ferulic acids. In particular, seeds from 0.02mM MJ treated Ben Hope black currants exerted contents of gallic, caffeic, p-coumaric and ferulic acids of 201.4, 125.9, 201.3 and 112.5μgg−1vs 124.3, 58.6, 165.4 and 95.8μgg−1 measured in seeds from untreated Ben Hope black currants. Comparable results were obtained for Ben Alder and Ben Gairn berries. Chemical elicitation with 0.02 MJ is proposed as an industrial practice in such a way that, after consideration of quality issues, it would be obtained high added value black currant seeds.

Preparation of Highly Purified Stearidonic Acid from Echium Oil via an Enzymatic Method Combined with Preparative High Performance Liquid Chromatography.

Stearidonic acid (SDA), an n-3 polyunsaturated fatty acid (PUFA), can be obtained from plant origin oils and it can be a good source of PUFA for vegetarians. SDA can be easily converted to longer PUFA such as docosahexaenoic acid and eicosapentaenoic acid. Highly purified stearidonic acid (SDA) was prepared successfully from echium oil via an enzymatic method combined with preparative high performance liquid chromatography. In the 1(st) step, SDA enrichment was accomplished using Candida rugosa lipase and 39.5% of SDA was obtained in the fatty acid fraction. Subsequently, the 1(st) reaction mixture was used for the 2(nd) enzymatic esterification without any separation process. The 2(nd) esterification was conducted for further SDA enrichment in a packed-bed reactor using Lipozyme RM IM from Rhizomucor miehei and the SDA content increased in a very short residence time. Ethanol was selected as an appropriate alcohol to react as an acyl receptor, and the other conditions for SDA enrichment were optimized at 20°C of temperature, and 1:4 of molar ratio (i.e., fatty acid to ethanol). Under these conditions, 51.6% of SDA was obtained in the fatty acid fraction after a residence time of 15 min. Finally, highly purified SDA (purity, >99%) was obtained by prep-HPLC using the SDA-rich fraction obtained from the two-step lipase-catalyzed esterification.

Enrichment of stearidonic acid from echium oil via a two‐step lipase‐catalyzed esterification

Stearidonic acid (SDA) from echium oil was enriched substantially by a two‐step lipase‐catalyzed esterification using Lipase OF from Candida rugosa and Lipozyme RM IM from Rhizomucor miehei. During the first step, SDA was enriched in the fatty acid fraction via C. rugosa lipase‐catalyzed esterification with lauryl alcohol. The optimum reaction conditions of water content, temperature, and enzyme loading were 0.25%, 30°C, and 2%, respectively, in terms of the content and yield of SDA. Under these conditions, SDA content was increased to 39.3 from 14.3% of the starting material. To further elevate SDA content, Lipozyme RM IM‐catalyzed esterification was then conducted using the SDA enriched fatty acid from the first step and a maximum SDA content of 54.1% was obtained. Using this two‐step lipase‐catalyzed esterification, SDA content increased fourfold from 14.3 to 54.1% with a 74.8% yield. γ‐Linolenic acid (GLA) was also enriched together with SDA.Practical applications: SDA, which is one of ω‐3 fatty acids, is considered as a source of health beneficial polyunsaturated fatty acids for vegetarians. SDA enrichment obtained in this study leads also to a high level of GLA. Therefore, this enrichment can be applied to produce a novel structured lipid containing a significant amount of SDA and GLA.

Lipase‐Catalyzed Acidolysis of Olive Oil with Echium Oil Stearidonic Acid: Optimization by Response Surface Methodology

AbstractIn this study, our aim was to enrich olive oil with stearidonic acid (SDA) together with polyunsaturated fatty acids (PUFA) by lipase‐catalyzed acidolysis using olive oil (OO) and free fatty acids of Echium oil, in the presence of Lipozyme® TL IM. The reaction conditions were optimized by using response surface methodology. A three‐factor, five level central composite circumscribed designs was used to generate the design points. The factors chosen were: substrate molar ratio (Sr, 4–6 mol/mol), reaction temperature (T, 55–65 °C), and reaction time (t, 6–9 h). Targeted incorporation (5 %) of SDA into OO was achieved at substrate molar ratio of 6 mol/mol, 55 °C, and 8.4 h. Model verification performed under these conditions for mg‐ and g‐scale production yielded SDA contents of 4.9 and 4.8 %, respectively. Moreover, it was observed that the structured lipid (SL) obtained under optimum conditions contained approximately 42 % oleic acid and 43 % PUFA including linoleic acid, α‐linolenic acid, and γ‐linolenic acid. Omega‐6/omega‐3 fatty acid ratio of SLs was 0.7. Analysis of oxidative properties resulted in lower oxidative stability of SL than unmodified OO. This type of SL containing SDA and other PUFA is believed to be beneficial for human health.

Enzymatic Synthesis of trans‐Free Structured Margarine Fat Analogues Using Stearidonic Acid Soybean and High Stearate Soybean Oils

AbstractEnzymatic synthesis of trans‐free structured margarine fat analogues from stearidonic acid (SDA) soybean oil and high stearate soybean oil was optimized using response surface methodology. The independent variables considered were the substrate molar ratio (2–5), temperature (50–65 °C), time (6–22 h), and enzymes (Lipozyme® TLIM and Novozym® 435). The dependent variables were mol% stearic acid incorporation and mol% SDA content. A good‐fit model was constructed using regression analysis with backward elimination and verified by a Chi‐square test. Desirable and optimal products composition were achieved at 50 °C, 18 h, 2:1, using Lipozyme TLIM, with 15.6 mol% stearic acid and 9.2 mol% SDA in the product and at 58 °C, 14 h, 2:1, using Novozym 435, with 14.8 mol% stearic acid and 6.4 mol% SDA. Using optimal conditions, structured lipids (SL) were synthesized in a 1 L stir‐batch reactor and free fatty acids removed by short‐path distillation. SL were characterized for their fatty acid profile, sn‐2 positional fatty acids, triacylglycerol profile, polymorphism, thermal behavior, and solid fat content. The SL had a desirable fatty acid profile, physical properties, and a suitable β′ polymorph content. These SL could be used as margarine fat analogues and an alternative to partially hydrogenated fat.

Increasing Stearidonic Acid (SDA) in Modified Soybean Oil by Lipase‐Mediated Acidolysis

AbstractThe objective of this work was to synthesize a structured lipid (SL) enriched in stearidonic acid (SDA, C18:4 ω‐3), from modified soybean oil (MSO) originally containing ~25% SDA. Low temperature crystallization (LTC) of MSO triacylglycerols (TAG) and free fatty acids (FFA) was performed. The TAG and FFA crystallization products (LTC‐TAG and LTC‐FFA, respectively) had SDA contents of 48.72 and 60.78%, respectively. Enzymatic acidolysis between MSO and LTC‐FFA was studied utilizing Novozym 435 and Lipozyme TL IM as biocatalysts. Substrate molar ratio, incubation time, solvent, and enzyme load were explored. Equilibrium was reached at 96 and 48 h for Novozym 435 and Lipozyme TL IM‐catalyzed reactions, respectively. The best conditions from these studies were also applied to the acidolysis of LTC‐TAG and LTC‐FFA. Utilizing Lipozyme TL IM and solvent free conditions, SLs with SDA contents of 37.61 ± 1.00% (20.86 ± 6.48% at sn‐2 position) and 53.46 ± 1.85% SDA (36.37 ± 3.14% at sn‐2 position) were obtained from the acidolysis reaction between MSO and LTC‐FFA, and LTC‐TAG and LTC‐FFA, respectively. Compared to the original SDA content of MSO, this process leads to a 52 and 116% increase in SDA content, respectively.

Searching for health beneficial n‐3 and n‐6 fatty acids in plant seeds

Various plant seeds have received little attention in fatty acid research. Seeds from 30 species mainly of Boraginaceae and Primulaceae were analysed in order to identify potential new sources of the n-3 PUFA α-linolenic acid (ALA) and stearidonic acid (SDA) and of the n-6 PUFA γ-linolenic acid (GLA). The fatty acid distribution differed enormously between genera of the same family. Echium species (Boraginaceae) contained the highest amount of total n-3 PUFA (47.1%), predominantly ALA (36.6%) and SDA (10.5%) combined with high GLA (10.2%). Further species of Boraginaceae rich in both SDA and GLA were Omphalodes linifolia (8.4, 17.2%, resp.), Cerinthe minor (7.5, 9.9%, resp.) and Buglossoides purpureocaerulea (6.1, 16.6%, resp.). Alkanna species belonging to Boraginaceae had comparable amounts of ALA (37.3%) and GLA (11.4%) like Echium but lower SDA contents (3.7%). Different genera of Primulaceae (Dodecatheon and Primula) had varying ALA (14.8, 28.8%, resp.) and GLA portions (4.1, 1.5%, resp.), but similar amounts of SDA (4.9, 4.5%, resp.). Cannabis sativa cultivars (Cannabaceae) were rich in linoleic acid (57.1%), but poor in SDA and GLA (0.8, 2.7%, resp.). In conclusion, several of the presented plant seeds contain considerable amounts of n-3 PUFA and GLA, which could be relevant for nutritional purposes due to their biological function as precursors for eicosanoid synthesis.Practical applicationsN-3 PUFA are important for human health and nutrition. Unfortunately, due to the increasing world population, overfishing of the seas and generally low amounts of n-3 PUFA in major oil crops, there is a demand for new sources of n-3 PUFA. One approach involves searching for potential vegetable sources of n-3 PUFA; especially those rich in ALA and SDA. The conversion of ALA to SDA in humans is dependent on the rate-limiting Δ6-desaturation. Plant-derived SDA is therefore a promising precursor regarding the endogenous synthesis of n-3 long-chain PUFA in humans. The present study shows that, in addition to seed oil of Echium, other species of Boraginaceae (Cerinthe, Omphalodes, Lithospermum, Buglossoides) and Primulaceae (Dodecatheon, Primula), generally high in n-3 PUFA (30–50%), contain considerable amounts of SDA (5–10%). Therefore, these seed oils could be important for nutrition.

Effect of feeding Atlantic salmon (Salmo salar L.) a diet enriched with stearidonic acid from parr to smolt on growth and n-3 long-chain PUFA biosynthesis

Vegetable oils (VO) have become the predominant substitute for fish oil (FO) in aquafeeds; however, the resultant lower content of n-3 long-chain (≥C20) PUFA (n-3 LC-PUFA) in fish has put their use under scrutiny. The need to investigate new oil sources exists. The present study tested the hypothesis that in Atlantic salmon (Salmo salar L.), a high intake of stearidonic acid (SDA) from Echium oil (EO) would result in increased n-3 LC-PUFA biosynthesis due to a lower requirement for Δ6 desaturase. Comparisons were made with fish fed on diets containing rapeseed oil (RO) and FO in freshwater for 112d followed by 96d in seawater. EO fish had higher whole-carcass SDA and eicosatetraenoic acid (ETA) in freshwater and prolonged feeding on the EO diet in seawater resulted in higher SDA, ETA, EPA and docosapentaenoic acid (DPA) compared with RO fish. Fatty acid mass balance of freshwater fish indicated higher biosynthesis of ETA and EPA in EO fish compared with fish fed on the other diets and a twofold increase in n-3 LC-PUFA synthesis compared with RO fish. In seawater, n-3 biosynthetic activity was low, with higher biosynthesis of ETA in EO fish and appearance of all desaturated and elongated products along the n-3 pathway. SDA-enriched VO are more suitable substitutes than conventional VO from a human consumer perspective due to the resulting higher SDA content, higher total n-3 and improved n-3:n-6 ratio obtained in fish, although both VO were not as effective as FO in maintaining EPA and DHA content in Atlantic salmon.

Co-expression of the borage Δ6 desaturase and the Arabidopsis Δ15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean

Two relatively rare fatty acids, gamma-linolenic acid (GLA) and stearidonic acid (STA), have attracted much interest due to their nutraceutical and pharmaceutical potential. STA, in particular, has been considered a valuable alternative source for omega-3 fatty acids due to its enhanced conversion efficiency in animals to eicosapentaenoic acid when compared with the more widely consumed omega-3 fatty acid, alpha-linolenic acid (ALA), present in most vegetable oils. Exploiting the wealth of information currently available on in planta oil biosynthesis and coupling this information with the tool of genetic engineering it is now feasible to deliberately perturb fatty acid pools to generate unique oils in commodity crops. In an attempt to maximize the STA content of soybean oil, a borage Delta(6) desaturase and an Arabidopsis Delta(15) desaturase were pyramided by either sexual crossing of transgenic events, re-transformation of a Delta(6) desaturase event with the Delta(15) desaturase or co-transformation of both desaturases. Expression of both desaturases in this study was under the control of the seed-specific soybean beta-conglycinin promoter. Soybean events that carried only the Delta(15 )desaturase possessed a significant elevation of ALA content, while events with both desaturases displayed a relative STA abundance greater than 29%, creating a soybean with omega-3 fatty acids representing over 60% of the fatty acid profile. Analyses of the membrane lipids in a subset of the transgenic events suggest that soybean seeds compensate for enhanced production of polyunsaturated fatty acids by increasing the relative content of palmitic acid in phosphatidylcholine and other phospholipids.

Stearidonic and γ-linolenic acid contents of common borage leaves

Rosette leaves of field-grown common borage contained both γ-linolenic acid (18:3ω6) and stearidonic acid (18:4ω3). Their contents varied during the growing period from 0.5 to 2.6 mg and from 5.7 to 9.0 mg g −1 leaf dry wt, respectively. Approximately the same amount of both acids was found in the stalk leaves. The highest values for total fatty acid content, as well as for both γ-linolenic and stearidonic acid contents, in newly developed rosette leaves were found in late June, whereas in stalk leaves maximum values for all of these parameters were found in September. Under controlled growth conditions the total fatty acid content as well as the content and/or percentage of y-linolenic and stearidonic acids in the rosette leaves were affected to some extent by light intensity.