Functional monoesters of jojoba oil can be produced by enzymatic interesterification: Reaction analysis and structural characterization

Abstract

AbstractLong‐chain monounsaturated fatty acid ethyl esters (LMFAEE) and fatty alcohol acetates (LMFAA) are important functional compounds in industry, and new sources are needed. In this study, jojoba oil was interesterified with ethyl acetate (EA) for the combined production of LMFAEE and LMFAA. Lipozyme RM IM and Novozym 435 were employed as the biocatalyst and their efficiencies were compared. Aliquot removal and subsequent 1H NMR analysis were used to monitor reaction progress and determine the interesterification yield (IY, %). Optimization of this reaction was conducted for both lipases with respect to four experimental parameters: temperature, EA content, immobilized lipase load, and reaction time. The highest IY in the presence of Novozym 435 was 97%, which was achieved after 9 hours of reaction at 37°C with 75 wt% EA and 5.00 wt% lipase load at 300 rpm, whereas the IY was 76% in the case of Lipozyme RM IM. The interesterified product was purified by preparative TLC and characterized by 1H NMR, FT‐IR and GC‐MS, indicating the main components are ethyl cis‐11‐eicosenoate (44%), cis‐11‐eicosenyl acetate (25%) and cis‐13‐docosenyl acetate (22%). Novozym 435 exhibited excellent operational stability over 17 interesterification cycles with ca. 12% IY decrease.Practical applications: Conversion of the rare LMF‐acid/alcohol source from jojoba oil to LMFAEE and LMFAA was realized in a one step interesterification reaction. The obtained jojobyl LMFAEE and LMFAA, in mixture or purified form, can serve as functional ingredients in various upmarket products, such as functional lipids, fragrances, cosmetics, pharmaceuticals and lubricants. Cis‐11‐eicosenyl acetate and cis‐13‐docosenyl acetate are also important insect pheromones in biological study. Additionally, the lipase reuse can help reduce cost significantly, making jojoba oil more economically attractive for industrial application.Jojoba oil was converted to long‐chain monounsaturated fatty acid ethyl ester (LMFAEE) and fatty alcohol acetate (LMFAA) via enzymatic interesterification with ethyl acetate. The resulting jojobyl LMFAEE and LMFAA have great potential for various upmarket applications in both industry and academia (e.g., fragrance, cosmetic, pharmaceutical and insect pheromone).