Revisiting the Enzymatic Epoxidation of Vegetable Oils by Perfatty Acid: Perbutyric Acid Effect on the Oil with Low Acid Value

• Published in: Journal of the American Oil Chemists' Society
• Main Authors: Liu, Wei, Chen, Jingnan, Liu, Ruili, Bi, Yanlan
• Other Authors: National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1007/s11746-016-2897-3; http://link.springer.com/content/pdf/10.1007/s11746-016-2897-3.pdf; http://link.springer.com/article/10.1007/s11746-016-2897-3/fulltext.html; https://onlinelibrary.wiley.com/doi/full/10.1007/s11746-016-2897-3

Abstract Enzymatic epoxidation of vegetable oils in the presence of free fatty acids has been well studied in recent years, by mainly using long chain fatty acids ( e.g. , stearic acid) as the active oxygen carrier. However, for the previous enzymatic processes, the acid value (AV) of final epoxidized oils using long chain fatty acids is high, and the free fatty acid is not easily removed in the post treatment with water. Aiming at developing a more sustainable process, enzymatic epoxidation of sunflower oil was revisited using different free fatty acids catalyzed by Novozym 435 (lipase B from Candida antarctica , provided by Novozymes, Bagsvaerd, Denmark). When long chain stearic acid was introduced into the epoxidation in toluene solvent, the epoxy oxygen group content (EOC) of 6.41 ± 0.19 % was obtained. Due to the poor water solubility of stearic acid, the AV of the final epoxidized oil product was very high (53.40 ± 1.34) after it was washed with water. Alternatively, current study shows that the epoxidation process using short chain butyric acid produced the final epoxidized oil with lower AV of 2.57 ± 0.11. When the enzymatic epoxidation of sunflower oil was optimized in the presence of butyric acid and Novozym 435, EOC of 6.84 ± 0.21 % was obtained, reaching an oxriane conversion of 96.4 ± 3.0 %. Therefore, introducing short chain butyric acid as an active oxygen carrier will provide an alternative to the present enzymatic epoxidation process and produce the desired epoxidized oil products with much lower AV only after simple water‐treatments, which will make the enzymatic epoxidation more attractive.