Evaluation of physicochemical changes in hard-boiled eggs stored at different temperatures

Gamaralalage Schithra Rukshan Eregama1, Shine Htet Aung2,4, Herath Mudiyanselage Jagath Chaminda Pitawala3, Mahabbat Ali2,5, Seong-Yun Lee2, Ji-Young Park2, Edirisinghe Dewage Nalaka Sandun Abeyrathne1,2, Ki-Chang Nam2,*
Author Information & Copyright
1Department of Animal Science, Uva Wellassa University, Badulla 90000, Sri Lanka
2Department of Animal Science and Technology, Sunchon National University, Suncheon 57922, Korea
3Department of Science and Technology, Uva Wellassa University, Badulla 90000, Sri Lanka
4Department of Zoology, Kyaukse University, Kyaukse 05151, Myanmar
5Department of Animal Production and Management, Sher-e-Bangla Agricultural University, Dhaka 1207, Bangladesh
*Corresponding Author: Ki-Chang Nam. E-mail:

© Copyright 2023 Korean Society for Food Science of Animal Resources. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Aug 04, 2023 ; Revised: Aug 30, 2023 ; Accepted: Sep 15, 2023

Published Online: Sep 21, 2023


Eggs that have been hard-boiled are frequently used as ready-to-eat food. Refrigerated and frozen storage of hard-boiled eggs causes issues, such as customer rejection owing to textural changes. The objective of this research is to ascertain how storage temperature affects hard-boiled eggs' alteration in texture over time. Medium-sized brown shell eggs were acquired from a local market, boiled at 100°C for 15 min, and then stored at room temperature (27°C), refrigeration (4°C), and freezing (-18°C) conditions for 0, 12, 24, and 48 h. Fourier transform infrared spectroscopy (FTIR), texture profile, visual observation using a gemological microscope, free amino acid content, and color were measured. Freezing had a substantial impact on the eggs' hardness, gumminess, chewiness, and cohesiveness (p < 0.05). The FTIR spectrums confirmed the textural changes in bonds of amide A (3271 cm-1), amide I (1626.2 cm-1), amide II (1539.0 cm-1), C=O stretch of COO- (1397 cm-1), asymmetric PO2- stretch (1240 cm-1). Gemological microscopic images confirmed structural changes in eggs stored at -18 °C. The free amino acid content was lower in fresh and frozen eggs than in the rest (p < 0.05). However, there was no discernible variation in the egg white's color when eggs were kept at 4°C (p > 0.05). Salmonella spp. was found exclusively in eggs kept at room temperature. In conclusion, hard-boiled eggs did not exhibit structural or chemical changes when stored at 4°C for up to 48 h compared to freezing and room temperature conditions.

Keywords: hard-boiled eggs; structural changes; egg white color; storage temperature