Novel Applications for Zein Nanoparticles

Christopher J. Cheng
Zein is major nitrogen storage protein that accounts for nearly half of the protein content of the corn grain. As a byproduct of starch and ethanol processing, it is generally recognized as safe (GRAS) and soluble in up to 70% ethanol. Historically, zein has been used for films and coatings. However, usage of the corn protein has diminished in recent years. New advances in food nanotechnology has renewed interest in zein. By forming the protein into stable nanoparticles capable of being
more » ... le of being dispersed in aqueous solution, zein can be used in many applications ranging from improving stability and digestion of functional ingredients or active biodegradable packaging. Developing novel applications for this protein would then add value to a waste product during the processing of corn.The formation of hydrophobic zein nanoparticles (ZNPs) would allow for easier dispersion in aqueous systems without further modification to increase hydrophilicity. However, their dispersibility and subsequent stability in aqueous systems is important for its functionality in food. Addition of sufficient ι-carrageenan (ι-CGN) prevented aggregation in the pH range of 5.25 to 6.75 and limited aggregation at pH 7.0. Enhanced stability was attributed to the adhesion of ι-CGN to the nanoparticle surface, as the ZNPs surface charge became significantly negative with introduction of ι-CGN. These particles remained stable for up to 30 days with significantly lower turbidity and greater resistance to gravitational separation when compared to ZNPs alone.Lutein was encapsulated in zein nanoparticles, and the bioaccessibility was determined by quantifying lutein content after exposure to in vitro gastric and intestinal conditions. It was found that ZNPs provided a protective environment for lutein in aqueous dispersions and would release the carotenoid into the small intestine by rapid breakdown of ZNP structure during intestinal digestion. However, the process or residual components must have limited uptake of lutein into mixed micelles. ZNPs ca [...]
doi:10.25394/pgs.7479788 fatcat:crpgaubmufc2jm5bwg5ftcajke