Microfluidization of liquid egg yolk: Modelling of rheological characteristics and interpretation of flow behavior under a pipe flow

Aim of this research was to study the effects of microfluidization [103 (MEY1), 138 (MEY2), 172 (MEY3), and 207 (MEY4) MPa] on the rheological characteristics of liquid egg yolk (EY). Apparent viscosity of EY increased as the microfluidization pressure increased. Power law parameter, K increased from 0.29 (MEY0) to 8.56 (MEY4), while n decreased from 1.01 (MEY0) to 0.57 (MEY4), demonstrating shear thinning characteristics. Power law, Bingham, Casson and Herschel–Bulkley models described the experimental data (R2 ~ 0.99) well. Thixotropic and anti-thixotropic behavior of microfluidized EY was observed in time-dependent rheology. Furthermore, as microfluidization pressure increased, Weltman model parameters (A and B) increased. In dynamic rheological analysis, MEY0 (control), MEY1, and MEY2 showed elastic solid-like behavior, while EY microfluidized at higher pressure showed liquid-like behavior (MEY3 and MEY4). Furthermore, damping factor (DF) of MEY3 and MEY4 was found to be >1 across the entire applied strain. The Reynolds numbers of the control and microfluidized EYs were computed, for microfluidized EY, a laminar flow has been observed. Food is made up of a variety of biological components with varying rheological properties. Understanding food and its rheological behavior is an important component of the food industry. Food rheological behavior analysis answers important problems like whether a certain food product will easily deform, flow through a pipe, or perform well as a topping. Furthermore, fluid characterization parameters such as flow consistency index and flow behavior index, obtained after modelling rheological data, can be further used to predict flow behavior and velocity profile in a pipe flow. This information is crucial during the development of industrial plant designs that include the selection of pumps and pipes. It provides computations for extruders, mixers, coaters, and homogenizers in process engineering. Moreover, this information is vital to determine operation parameters during mass and heat transfer. •Steady state rheology exhibited shear thinning behavior of microfluidized EY.•Power law modelling showed increase in K and decrease in n post microfluidization.•Weltman model parameters (A and B) increased for microfluidized EY.•Strain sweep showed viscoelastic behavior of microfluidized EY.•Microfluidized EY demonstrated laminar flow.