Interaction of maize zein with wheat gluten in composite dough and bread as determined by confocal laser scanning microscopy

• Published in: Scanning Vol. 24; no. 1; pp. 1 - 5
• Main Authors: Bugusu, Betty A., Hamaker, Bruce R., Rajwa, Bartlomiej
• Format: Journal Article
• Language: English
• Published: New Jersey Wiley Periodicals, Inc 01.01.2002
• Subjects: Bread; composite dough; confocal laser scanning microscopy; Glutens - metabolism; Glutens - ultrastructure; Microscopy, Confocal; microstructure; Triticum - chemistry; Zea mays - chemistry; Zein - metabolism; Zein - ultrastructure
• ISSN: 0161-0457; 1932-8745
• DOI: 10.1002/sca.4950240101

Protein body‐free maize zein, when mixed at 35°C (above its glass transition temperature range), significantly (p < 0.01) improved the rheological and leavening properties of sorghum‐wheat composite flour dough, resulting in improved loaf volume. Confocal laser scanning microscopy was used to observe the structure of zein fibrils and the interaction between zein and gluten proteins in the composite dough and bread systems. Autofluorescence and immunolocalization techniques were used to locate gluten and zein, respectively. Optical sections were collected every 0.4 μm through the samples and digitally processed to produce reconstructed three‐dimensional images. Results showed that zein fibrils form an outer layer that intermittently coats the gluten networks, thereby strengthening them. This type of microstructure is able to withstand the pressure exerted by gas cell expansion during yeast fermentation to increase loaf volume.