# Effects of Supplementation of Different Proteins on the Rheological Properties of Liquid Whole Eggs
## 1 Introduction  
Protein is an essential macronutrient of a healthy diet. Consumers believe that adding a high amount of protein to their dietary intake has multiple benefits, such as weight management, satiety, and weight loss. Egg and whey proteins are two widely recognized sources of high-quality protein, each offering distinct advantages for muscle growth, recovery, and overall health benefits. Egg protein, derived from egg white, is a complete protein known for its superior digestibility and bioavailability [1]. As for whey protein, sourced from milk during the cheese-making process, it is known for its rapid absorption and comprehensive amino acid profile. Whey protein is often favored for post-exercise supplementation due to its fast digestion and stimulation of muscle protein synthesis [2]. Egg products are all forms of eggs that are removed from the shell and processed, making them more microbiologically stable, more commercial, and more industrially used [3]. There is a large supply of egg derivatives, such as dried, liquid, and frozen eggs, all being used as ingredients in food services or formulas. Liquid eggs and liquid eggfractures possess a desirable functionality that is used widely in different manufacturing processes such as foaming, gelation, coloring, and flavoring as well as emulsification. For their functional properties, liquid egg products are used in several products, such as pasta preparation, baked goods, meat and seafood products, mayonnaise, and salad dressing [4]. Rheology properties are used to understand the response of a certain food toward stress and forces, offering useful information regarding its structure and interaction with other components [5]. It plays a crucial role in food development, knowing the rheological behavior of food can enhance its texture and quality, resulting in an increase in customer satisfaction. Low-fat mayonnaise, for example, was developed by studying the texture and mimicking the rheological behavior of full-fat mayonnaise [6; 7]. Many vegan alternatives are created using the same concept. Milk alternatives, whether derived from nuts or legumes, and vegan ice creams are developed with careful consideration of the rheological properties of their traditional products to replicate texture, mouthfeel, and overall sensory experience [8]. Similarly, studying the rheological behavior of traditional chocolate, including its melting profile and mouthfeel, allowed food developers to create sugar-free chocolate with sugar substitutes like erythroid and stevia [9]. Knowing the importance of liquid eggs in the food industry, studying their properties is a must to determine quality, sensory evaluation, and the right processing method and instrument. Understanding the flow velocity of liquid whole eggs makes it easier to predict its behavior in tubes and pipes during pasteurizing, cooling, drying, and transporting [10]. Several studies found that the rheological characteristics of eggs lean toward a Newtonian as well as time-dependent non-Newtonian shear thinning behavior [11; 12; 13]. A study investigating the rheological behavior of egg whites, for both thick and thin portions and at different temperatures, found that the viscosity of egg whites decreases with an increase in temperature. Different rheological behavior was observed for the thin and thick portions of egg white at 5 \({}^{\circ}\)C; the thin portion showed no decrease in viscosity with shearing time at constant shear rates, while the thick portion showed a decrease within the first 6 min of shearing and then remained constant [14]. More studies investigating liquid egg rheological properties found that liquid egg white and liquid whole egg rheological behavior are more heat sensitive than liquid egg yolk; liquid whole egg showed a fluctuation in apparent viscosity around pasteurization temperature leaning toward thixotropic behavior in comparison to liquid egg white, which was more stable.