Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2024
Publication Date: 7/16/2024
Citation: Compton, D.L., Pero, B.A., Radloff, G.H., Evangelista, R.L., Winkler-Moser, J.K., Kenar, J.A., Cermak, S.C., Appell, M.D., Evans, K.O., Wegener, E.C., Rheay, H.T., Skory, C.D. 2024. Lipase-catalyzed transesterification of virgin and refined hemp seed oil with ferulic acid ethyl ester. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.12849.
DOI: https://doi.org/10.1002/aocs.12849

Interpretive Summary: New, economically viable, agri-based materials must be developed to sustain a bioeconomy with natural, renewable products that can replace petroleum-based products. For example, ultraviolet (UV) absorbents used in many personal care products are derived from petroleum-based products and are potentially associated with adverse environmental and health effects. This research has established a biobased method to convert hemp seed oils and compounds abundant in corn and wheat bran into UV absorbing and antioxidant products that can be used in the personal care industry. This research demonstrated that the conversion process was equally efficient with refined, cold pressed hemp seed oil and less expensive virgin, cold pressed hemp seed oil without effecting the production of the final product or the UV absorbance and antioxidant ability of the final product. Using virgin instead of refined seed oil will provide an 11% cost savings for the seed oil feedstock in the manufacturing process. The modified hemp seed oil products are a potential commercial product as ultraviolet absorbents and antioxidants in the $60 Million (United States and European Union, 2022, projected to grow 5% annually) personal care, natural ingredients market. This research creates new, expanded market opportunities for agricultural commodities and combats climate change by reducing dependence on petroleum-based chemicals.

Technical Abstract: The transesterification of ethyl ferulate (EF) and unrefined, virgin, cold pressed hemp seed oil (HOV) and refined, bleached, deodorized cold pressed hemp seed oil (HOR) using a commercial lipase, Novozym 435 (Candida antarctica B lipase immobilized on an acrylic resin), was examined in 150-mL, shaken, batch reactions at 60°C for two weeks. The reactions produced feruloylated hemp seed oils, FHOV and FHOR, respectively, and the reactions were monitored to determine the difference between virgin and refined hemp seed oil on the transesterifications. The FHOV and FHOR reactions both reached EF conversion equilibrium of 58% after ca. 168h. Ultraviolet (UV) absorbing and antioxidant capacity of the FHOV and FHOR were determined. Both FHOV and FHOR (50 mM in ethanol) were excellent UVA II absorbers, lambda-max 322 nm, and exhibited absorption into the UVB. The DDPH* radical (200 micro-M) scavenging of the FHOV and FHOR (0.25–2.5 mM) were both shown to be rapid antioxidants (50% DDPH* radical scavenged in <5 min) at 1.0 and 2.5 mM suggesting that inherent components contained in the HOV did not adversely affect enzyme activity relative to transesterification using HOR. Overall, using less expensive, unrefined, virgin hemp seed oil vs. more expensive, refined hemp seed oil did not appreciably affect the enzyme kinetics of the transesterification reactions nor the UV absorbing and antioxidant efficacy of the resultant feruloylated hemp seed oils, making FHOV a less expensively produced feruloylated hemp seed oil for cosmetic and personal care applications.