Functionalizing zein through antisolvent precipitation from ethanol or aetic acid

Zein forms viscoelastic networks in water which have shown to be extremely brittle and demonstrate low yield strength. This work investigates an alternative method of preparing zein networks through antisolvent precipitation, involving dissolution in ethanol or glacial acetic acid followed by precipitation by addition of excess water. The rheological and structural properties of the zein networks were analyzed and determined that modifications in functionality were solvent-dependent. Precipitation from ethanol resulted in a network with a highly organized, porous structure of increased ductility. In contrast, precipitation from glacial acetic acid resulted in a highly plasticized, continuous network, but only demonstrated a slightly reduced brittleness compared to control networks. The functionality of each network was retained over 24 h of storage. Overall, antisolvent precipitation was able to improve the functionality of zein networks for the purpose of food structuring, and also presented the additional advantages of being simple, inexpensive, and food grade.