Thermal Processing of Liquid Egg Yolks Modulates Physio-Chemical Properties of Mayonnaise

Abstract

In this study, the effect of various heating temperatures (61–70 °C) and times (1–10 min) on physical and chemical properties of liquid egg yolk (LEY) and mayonnaise were investigated. Initially, we found that the increase of LEY protein denaturation was highly correlated with the increase of temperature and time, without causing either protein degradation or aggregation. In addition, the viscosity and particle size of LEY were significantly increased with greater heating temperature and time. Furthermore, the emulsification stability of mayonnaise prepared from thermally processed LEY were significantly better than that of the unheated control group, in particular, the emulsion stability of mayonnaise was higher at a temperature ranging from 62 °C to 68 °C, whereas the emulsion stability decreased above 69 °C. A rheological analysis showed that mayonnaise prepared from thermally processed LEY has higher shear stress when compared with the control group. Indeed, a sharp increase in the shear stress was observed when LEY was heated above 67 °C. Results from storage behavior analysis suggest that mayonnaise prepared from thermally processed LEY failed to affect the chemical qualities of mayonnaise, as evidenced by the fact that acid values and TBA values were not statistically significant with the unheated control group. Microscopic observation indicates that the number of complete oil droplets were significantly reduced at higher heating (70 °C/5 and 10 min) conditions. Finally, the sensory evaluation results suggest that mayonnaise prepared from thermally processed LEY does not influence the appearance, aroma, taste, greasy feeling, and overall acceptance of mayonnaise, as indicated by there being no significant differences between the experimental group and the control group (p > 0.05). We conclude from our study that a combination of heating conditions over 67 °C/5 min can allow the mayonnaise to retain better quality in terms of stability.

Quantitative Lipidome Analysis of Boiled Chicken Egg Yolk under Different Heating Intensities

“…Among them, a significant decrease in the abundance of 12 phospholipids and a significant increase in the abundance of 12 lysophospholipids, 9 Cers, 1 PA, and 17 related FFAs were observed in the comparison of HEY/FEY (Figure 7A). Similarly, a significant decrease in the abundance of five phospholipids and a significant increase in the abundance of 2 Cers and 12 FFAs were found in the comparison of The TGs in egg yolk are mainly in the form of LDL, as a lipid core wrapped by a phospholipid monomolecular layer [27]. Heat treatment causes denaturation and structural remodeling of LDL, resulting in a change in the state or presence of TGs, which makes it easier for them to be extracted with solvents (methyl tert-butyl ether and methanol mixture, 3:1, v/v).…”

“…In the process of converting an egg yolk from a liquid to a solid under heat treatment, that is, in the process of forming yolk gel, various physicochemical interactions occur between the components of the egg yolk [ 25 ]. Some studies reported that the aggregation of low-density lipoprotein (LDL) and yolk particles in egg yolk begins to occur at 65–70 °C; however, at this point, a continuous gel was not found to have started to form [ 26 , 27 ]. Therefore, the HEY is still in a fluid form and did not start to form a gel.…”

“…The TGs in egg yolk are mainly in the form of LDL, as a lipid core wrapped by a phospholipid monomolecular layer [ 27 ]. Heat treatment causes denaturation and structural remodeling of LDL, resulting in a change in the state or presence of TGs, which makes it easier for them to be extracted with solvents (methyl tert-butyl ether and methanol mixture, 3:1, v/v ).…”

The effects of high‐intensity ultrasonic treatment on emulsification, rheological properties, and flow behavior of liquid egg yolk

“…The diluted liquid egg yolks were prepared according to the description of Ho et al. (2022) with modifications. The eggshell was lightly tapped with a separator to separate the egg white from the egg yolk.…”