Improved Physical Properties of Frozen Chicken Egg Gels with Olive Leaf Extract Fortification

Agus Bahar Rachman1,2,*, Masahiro Ogawa3, Takashi Akazawa4, Andi Febrisiantosa1, Rina Wahyuningsih1, Teguh Wahyono1, Tri Ujilestari1, Nicolays Jambang1, Lukman Hakim1, Angga Maulana Firmansyah1
Author Information & Copyright
1Research Center for Food Technology and Processing, National Research and Innovation Agency, Yogyakarta 55861, Indonesia.
2Department of Food Technology, Faculty of Agriculture, State University of Gorontalo, Gorontalo 96128, Indonesia.
3Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kagawa 7610795, Japan.
4Graduate School of Science and Technology, Niigata University, Niigata 9502181, Japan
*Corresponding Author: Agus Bahar Rachman. E-mail:

© Copyright 2024 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: May 06, 2024 ; Revised: Jun 06, 2024 ; Accepted: Jun 16, 2024

Published Online: Jul 09, 2024


The research focused on evaluating the impact of the effects of olive leaf water extract (OEx4) on the microbiological and physical properties of egg gels, as well as how it protects the gels' rheological properties throughout freeze-thaw cycles. Egg gels with added OEx4 at concentrations of 0.03% and 0.1% (w/w) to minced whole egg (WE) and egg white (EW) were frozen at -20℃ for five days, undergoing three freeze-thaw cycles. Unlike the control egg gels without OEx4, which showed increased thawing weight loss across the cycles, the weight of OEx4-egg gels remained consistent. The control egg gels experienced a reduction in while the OEx4-egg gels remained stable water-holding capacity, breaking strength, elasticity, and viscosity. Scanning electron microscopy revealed that, in contrast to control egg gels, the OEx4-egg gels preserved a structure akin to their non-frozen state even after freezing. These findings suggest that OEx4 imparts freeze-resistance to egg gels. Additionally, OEx4 application improved the interaction between non-polar groups and water molecules, in egg gels leading to a rise in pH. Then, OEx4 has been found to effectively hinder the proliferation of bacteria while also minimizing the occurrence of gel contamination in eggs subjected to the freeze-thaw process. Therefore, OEx4 proves to be beneficial in enhancing the physical, chemical and microbiological properties of frozen processed poultry products.

Keywords: Olive Leaf Extract; Frozen Food; Egg Gel