Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2006
Publication Date: 1/1/2007
Citation: Compton, D.L., Kenar, J.A., Laszlo, J.A., Felker, F.C. 2007. Starch-encapsulated, soy-based ultraviolet-absorbing composites with feruloylated monoacyl- and diacylglycerol lipids. Industrial Crops and Products. 25(1):17-23.
Interpretive Summary: The goal of our project is to develop new, environmentally benign methods to help convert a portion of the 800,000 lbs of excess soybean oil produced in the U.S. to new, value-added uses, such as nutritional, industrial, and cosmetic ingredients. We have developed a new, patented material that we make from the combination of soybean oil and ferulic acid, a compound of the cinnamon family, found in plants. The ferulic acid portion absorbs ultraviolet (UV) A and B radiation while the oil portion is water insoluble. These characteristics make the new material, SoyScreen(TM), an ideal all natural replacement for petroleum-based UVA and UVB absorbers currently used in sunscreens, cosmetics, and other industrial uses such as paints and coatings. The work done in this study shows that the SoyScreen(TM) oil can be made into very small droplets, which we coated with starch. The starch coated SoyScreen(TM) has superior UV absorbing ability, and the starch coating allows the oil to be dispersed into water without the need for surfactants or emulsifiers. This will allow the use of SoyScreen(TM) to be expanded into the agricultural industry where it will be formulated into water-based sprays. The SoyScreen(TM) will act as an all-natural UV protectant to prolong the life of the herbicide and pesticide active ingredients in agricultural sprays, thus potentially requiring fewer applications. The enhanced UV absorbance and water compatibility will also expand SoyScreen’s(TM) use in the sunscreen, cosmetic, and personal care industries.
Technical Abstract: Ultraviolet absorbing lipids were synthesized from the transesterification of soybean oil with ethyl ferulate catalyzed by the commercial lipase, Novozym 435 (Candida antartica lipase B). The resultant feruloylated monoacyl- and diacylglycerols (FAG) were encapsulated as microdroplets within a starch matrix via steam jet cooking (140 degree C and 225 kPa). Up to 50% (wt/wt) of the feruloylated lipids was encapsulated into the starch matrix with the microdroplets ranging in size from 1 to 10 micrometer. Transmittance and irradiance measurements of ultraviolet radiation (300 to 400 nm) through thin films of the neat and starch-encapsulated FAG showed that the FAG retained its ultraviolet absorbing efficacy after steam jet cooking. Furthermore, starch-encapsulation of the FAG was found to enhance the ultraviolet absorbance of the feruloylated lipids. When encapsulated in the starch matrix half of the coverage (mg/cm^2) of FAG was required to block the same amount or more ultraviolet radiation as neat FAG. The starch-encapsulated FAG was formulated as an aqueous dispersion without the need for emulsifiers or surfactants. The dispersions were drum dried to a powder and shown to be easily reconstituted into water dispersions without the loss of ultraviolet absorbing efficacy.