Impact of high-pressure shift freezing on physicochemical and functional properties of egg edible parts

• Published in: Journal of food engineering 2024-01, Vol.361, p.111753, Article 111753
• Main Authors: Dadashi, S., Fernández-Martín, F., Mousavi, M., Pérez-Mateos, M.
• Format: Article
• Language: English
• Subjects: atmospheric pressure; denaturation; egg albumen; Egg white; Egg yolk; eggs; electrophoresis; enthalpy; Freezing processes; Functional properties; High-pressure shift freezing; phase transition; protein denaturation; protein solubility; Thermal properties; viscoelasticity
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2023.111753

Effects of high-pressure shift freezing (HPSF) at 200 MPa/-20 °C on physical, functional and thermal properties of egg white and egg yolk from three egg types were studied. The phase transition time in HPSF was shorter compared to atmospheric freezing (about 25% for egg yolk and 56% for egg white) due to the high degree of supercooling. The effect of freezing on functional properties seems to be related to different degrees of protein denaturation depending of the freezing/pressure level. Partial protein unfolding (suggested by higher free sulfhydryl) was observed after freezing at atmospheric pressure, especially for egg yolk. On the other hand, higher protein aggregation due to lower thermal denaturation enthalpy (50% in egg yolk and 70% in egg white) was found in HPSF samples, supported by decrease of protein solubility, disappear of electrophoretic bands and increase in viscoelasticity (G′ and G″ values). •Egg white and yolk of three eggs types were frozen under high-pressure shift freezing (HPSF).•HPSF process led to a significant reduction in the phase transition time.•Egg yolk was more affected by the freezing process, with less change at atmospheric pressure.•Freezing induced gelling of yolk egg and aggregation of white egg proteins.