Ohmic baking of gluten-free bread: role of non-gluten protein on GF bread structure and properties

Batter stabilisation presents a great challenge for gluten-free (GF) bread, as CO2 is released during bread-making process, resulting in small, dense and crumbly breads. Apart from starch, protein plays a crucial role in gas cell stabilisation. This study aims to assess the effect of non-gluten protein from different sources (plant and animal) on GF batter's rheological behaviour (pasting properties, rheology and foam stability) and on bread properties after baking with conventional and ohmic heating method. Hence, this study evaluated the functional properties (protein solubility, hydrophobicity, sulfhydryl groups, foaming and emulsification properties) of selected non-gluten protein relevant for foam stabilisation. Furthermore, a correlation matrix was established by involving the functional properties of the proteins and their interaction with starch on batter rheology and bread quality. Among proteins, egg albumin and potato proteins were reported to perform superior functionality in GF bread; in particular, potato protein generated breads with the highest volume for both baking methods, which was potential to replace egg albumin. According to the correlation matrix, protein solubility was required in foaming and emulsification behaviour to improve GF bread properties.