Multi-objective development of novel egg free cakes using quinoa protein and its quality attributes

Abstract

This study explores the potential of utilizing quinoa protein as an egg substitute in bakery products for customers with health, culture/religion, or dietary restrictions. Quinoa protein was prepared from quinoa seed by alkaline solubilization followed by isoelectric precipitation and drying. Four different formulations of egg-free cakes were prepared by incorporating quinoa protein in egg equivalents of 50 g (Formulation 1), 75 g (Formulation 2), 100 g (Formulation 3), and 150 g (Formulation 4). The research involved Fourier-transform infrared spectroscopy and revealed such functional properties as proximate composition, physical properties, color, texture, microstructure, and sensory characteristics for the batters and the cakes. The incorporation of different quinoa protein concentrations significantly (p < 0.05) affected all the functional properties of the batters and the cakes. Such variables as crude protein and ash increased while moisture and fat contents decreased. The baking loss went down as the share of quinoa protein went up. The structural analysis showed an increase in gumminess and chewiness accompanied by a decrease in cohesiveness and elasticity. The analysis also revealed hardness and non-uniform changes. The lightness (L*) and yellowness (b*) of the cake surface and crumb decreased while the redness (a*) increased. The cakes prepared according to Formulation 4 with the greatest share of quinoa protein had a high nutritional value with reasonable concentrations of essential amino acids in general and a high level of lysine in particular. The same sample also received the highest score for overall sensory properties. The sensory assessment proved that quinoa protein could meet consumer expectations of egg-free cakes.