Development of a heatable duck egg white translucent jelly: an evaluation of its physicochemical properties and thermal stability

Nian-Yao Zheng; Yi-Chen Chen; Yen-Po Chen; Jia-Shian Shiu; Sheng-Yao Wang

doi:10.1016/j.psj.2021.101373

Development of a heatable duck egg white translucent jelly: an evaluation of its physicochemical properties and thermal stability

Poult Sci. 2021 Sep;100(9):101373. doi: 10.1016/j.psj.2021.101373. Epub 2021 Jul 2.

Authors

Nian-Yao Zheng¹, Yi-Chen Chen¹, Yen-Po Chen², Jia-Shian Shiu³, Sheng-Yao Wang⁴

Affiliations

¹ Department of Animal Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
² Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
³ Hengchun Branch, Livestock Research Institute, Council of Agriculture, Executive Yuan, Pingtung 946, Taiwan.
⁴ Department of Animal Science and Technology, National Taiwan University, Taipei 10617, Taiwan. Electronic address: yaoyao@ntu.edu.tw.

Abstract

Though nutritional, the remaining separated duck egg white in duck egg processing plants presents challenges for its transportation and use, as it spoils easily and has a strong odor. Uses for the excess egg white are of paramount concern for agricultural resource reuse. The purpose of this study was to increase its value and use efficiency. Duck egg white was mixed with sodium hydroxide to produce translucent alkali-induced egg white jelly similar to that in preserved egg whites. To develop a heatable translucent egg white jelly, their physiochemical properties and thermal stabilities were investigated. A gel prepared with 150 mM sodium hydroxide at 25°C had optimal bloom strength and the densest microstructure. Storing the jelly at 5°C helped maintain its disulfide bonds and delayed liquefaction. Although heating decreased its bloom strength and total disulfide bond content as temperature increased (P < 0.05), scanning electron microscopy of the heated jelly revealed that the protein network structure was denser than that of unheated jelly. Heating caused parts of the structure to shrink and even dehydrate, leading to a wrinkled surface. However, no signs of liquefaction or collapse were observed, and the free alkali released during heating was lower than that from the white of existing preserved eggs. These results confirmed the thermal stability of the jelly and its potential to be served hot or used in food processing. Furthermore, in addition to disguising the odor and special flavor attributable to the alkaline treatment, adding ginger juice or turmeric to the preparation yielded higher bloom strength, resulted in lower free alkalinity, and delayed liquefaction, thus improving the jelly's thermal stability. Like preserved eggs on the market that can be served in hot congee, the proposed egg white jelly is rich in proteins and suitable for hot or instant serving. These findings may help address the problem of excessive remaining duck egg white created during food processing by diversifying duck egg processing and boosting its value.

Keywords: duck egg white; ginger; heatable translucent jelly; turmeric.

MeSH terms

Animals
Chickens
Ducks*
Egg White* / analysis
Food Handling
Ovum