Protein–lipid interactions in gluten elucidated using acetic acid fractionation

• Published in: Food chemistry Vol. 115; no. 1; pp. 105 - 112
• Main Authors: McCann, Thu H., Small, Darryl M., Batey, Ian L., Wrigley, Colin W., Day, Li
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2009; [Amsterdam]: Elsevier Science; Elsevier
• Subjects: Acetic acid; Biological and medical sciences; Bound lipids; breadmaking; breadmaking quality; Cereal and baking product industries; food analysis; food composition; Food industries; food matrix; fractionation; Free lipids; Fundamental and applied biological sciences. Psychology; gliadin; Gluten; glutenins; glycolipids; hydrophobicity; Monomeric protein and polymeric protein; Protein–lipid interactions; Protein–lipid interactions; Monomeric protein and polymeric protein; Free lipids; Bound lipids; Acetic acid; Gluten; Fractionation; Protein-lipid interactions; Interaction; Plant protein; Lipids
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2008.11.070

Protein–lipid interactions in dough have an important impact on the quality of bakery products. Understanding of protein–lipid interactions in gluten can enhance the development of technological solutions to improve the breadmaking quality of flour as well as the functional properties of gluten. In this study, acetic acid at two different concentrations was used for treating and fractionating gluten. The impact of these procedures on the distribution of lipid components was measured. Acetic acid was able to dissociate non-polar lipids from the gluten protein matrix. Upon fractionation monomeric proteins (predominantly gliadins) and phospholipids were high in the 0.01 M acetic acid soluble fraction. The subsequent fractionation step using 0.1 M acetic acid resulted in an increased amount of high-molecular-weight glutenin subunits (HMW-GS) in the soluble fraction, along with more non-polar lipids and glycolipids in both the free and bound lipid extracts. The distribution of lipid classes demonstrates that non-polar lipids are either associated with the glutenin polymeric network through hydrophobic interactions or entrapped within the gluten matrix. The results also indicate that in gluten, glycolipids are likely to be associated with glutenins through both hydrophobic interactions and hydrogen bonds whilst phospholipids preferentially interact with gliadins and lipid binding proteins.