Structure and physical properties of seed proteins. I. Glass transition and crystallization of zein protein from corn

Abstract

AbstractThermal behavior of a seed protein, zein from corn, was studied by differential scanning calorimetry (DSC), thermogravimetry (TG), thermal expansion, X‐ray diffraction, and infrared spectroscopy. Zein film cast from aqueous ethanol is amorphous in the randomcoil conformation. Water in the specimen is lost by evaporation at about 100°C. The glass transition is observed at 165°C. The amorphous zein crystallize to β‐crystals at about 210°C accompanied by the random‐coil → β‐form conformational transition. The thermal degradation of zein occurs at about 320°C. Steam treatment of zein film results in the conformational change to the α‐ and β‐forms, simultaneously, irrespective of treating temperature. © 1992 John Wiley & Sons, Inc.