Incorporation of plasticizers and co-proteins in zein electrospun fibers

Authors: FEDERICI, ENRICO - Purdue University; Selling, Gordon; CAMPANELLA, OSVALDO - The Ohio State University; JONES, OWEN - Purdue University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2020
Publication Date: 11/24/2020
Citation: Federici, E., Selling, G.W., Campanella, O., Jones, O. 2020. Incorporation of plasticizers and co-proteins in zein electrospun fibers. Journal of Agricultural and Food Chemistry. 2020 68(49), 14610-14619. https://doi.org/10.1021/acs.jafc.0c03532.
DOI: https://doi.org/10.1021/acs.jafc.0c03532

Interpretive Summary: Corn protein (zein) was considered for evaluation, and to provide consumers with an option for high quality gluten-free bread. Zein in fiber form was required to accomplish this task. One proven method to produce zein fibers is the electrospinning process. In the electrospinning technique, small amounts of zein solution can be used to prepare suitable thin fibers which may be incorporated into bread. The zein solutions and fibers were fully characterized on their own or as blends of zein with other proteins or plasticizers (which are used to modify the zein properties). All components could be used in food preparation. The solution and fiber properties of the zein co-protein blends and zein plasticizer combinations demonstrated that they could make acceptable fibers. These results support the evaluation of fibers composed of zein with other proteins or plasticizers in bread. The data reported here would be of value to researchers that are carrying out work to increase the value of corn co-products as well as researchers interested in producing higher value gluten-free products. All participants in the corn value chain as well as consumers that are sensitive to gluten, will benefit from this research.

Technical Abstract: As a means to alter the physical properties of electrospun zein fibers, plasticizers (glycerol, lactic acid and oleic acid) or co-proteins (casein, whey proteins, rice proteins) were mixed with zein using the solvents acetic acid or aqueous ethanol with or without sodium hydroxide. Incorporating plasticizers or co-proteins had a negligible impact on solution viscosity, solution surface tension, and fiber formation, although electron microscopy of fiber mats showed an increase in bead formation with added co-proteins. Gel electrophoresis identified casein and whey protein in spun mats, yet it could not be verified if they were located in beads rather than fibers. Infrared spectra demonstrated inclusion of plasticizers in fiber mats. Glycerol, oleic acid, and lactic acid reduced glass transition temperature of bulk fibers, while nano-indentation showed reduced Young’s moduli of individual fibers. Thus, it is feasible to incorporate food-grade plasticizers or additional proteins within zein fibers to modify their function.