Functional protein beverage with milk and egg white: physical properties, formulation, protein contents and amino acids components

Generally, between protein sources, whey proteins are often used in ready-to-drink protein beverages, but in the current study, because of the important nutritional role, egg white protein was investigated. Beverages were formulated with two different amounts of egg white powder (EWP) (14 and 16%), cocoa powder (1 and 2%) and sugar (2.8 and 3.8%), carrageenan stabilizer (0.05%) with two types of (pasteurization and sterilization) milk. The stability, viscosity, total solids and protein content of samples were measured at 1st, 5th, 7th, and 10th days of storage at 4°C. The results showed that Egg White Protein (EWP) could increase viscosity up to 1.9 to 3.5 times (P < 0.05). In spite of the direct relation between the increase of EWP amount and viscosity increase, this relation was totally reversed during storage time. There was also a positive relationship between temperature increase and viscosity. On the other hand, EWP acted as a stabilizing agent and significantly caused to decrease phase separation and sedimentation of the samples and it was direct relation between the amount of EWP and temperature with stability of the samples. Also, the total solids content of the treated samples became doubled compared to the control samples. This drink contained good amounts of amino acids such as glutamic acid, aspartic acid, leucine, lysine, valine and serine. Totally, the best formulated beverage was (14% egg white powder, 2% cocoa powder, 3.8% sugar and 0.05% stabilizer) with protein content of 14.6% and optimal viscosity and the best stability.