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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. g-Linolenic acid (GLA) was also enriched together with SDA.Practical applications: SDA, which is one of v-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.

A packed‐bed reactor (length 6.5 cm; id 4.65 mm) has been used to enrich docosahexaenoic acid (DHA) via the lipase‐catalyzed esterification of the fatty acid from tuna oil with ethanol. Lipozyme RM IM (from Rhizomucor miehei) was used for the esterification reaction because of its ability to discriminate between different fatty acids, and several reaction parameters, including the temperature, molar ratio of substrates, and water content were explored as a function of residence time. In this way, the optimum conditions for the enrichment process were determined to be a temperature of 20 °C, a molar ratio of 1:5 (i.e., fatty acid to ethanol), and a water content of 1.0 % (based on the total substrate weight). Under these conditions, a residence time of 90 min gave a DHA concentration of 70 wt% and a DHA recovery yield of 87 wt% in the residual fatty acid fraction.

Supine and sitting positions during the administration of oral contrast media provided better ileal distension than the right decubitus position in obtaining CTE. Advances in knowledge: The performance of CTE largely depends on adequate luminal distension and wall visualization. As the terminal ileum is the predominant site of small bowel pathology for inflammatory bowel disease, the supine or sitting position would be preferable for patients who are suspected of having small bowel pathology.

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