Effect of salting and dehydration treatments on the physicochemical and gel properties of hen and duck egg yolks, plasma and granules

Abstract

BackgroundSalted hen egg yolks are less oily and less flavorful than salted duck egg yolks. However, hen eggs have a more adequate market supply and have a broader application prospect than duck eggs. In this study, egg yolks, plasma, and granules were dehydrated by adding 1% NaCl to simulate traditional curing process of salted egg yolk. The changes in the pickling process of hen egg yolks (HEY) and duck egg yolks (DEY) plasma, and granules were compared to reveal the gelation mechanism and the underlying causes of quality differences in salted HEY and DEY. Salted HEY can be compared with the changes in DEY during the pickling process to provide a theoretical basis for the quality improvement of salted HEY to salted DEY.ResultsThe results showed that both plasma and granules were involved in gel formation, but exhibited different aggregation behaviors. Based on the intermolecular forces, the HEY proteins achieved aggregation mainly through hydrophobic interactions and DEY proteins mainly through covalent binding. According to spin–spin relaxation time, HEY gels immobilized a large amount of lipid and interacted strongly with lipids. DEY gels showed much free lipid and had weak interaction with lipid. The microstructure showed that HEY proteins were easily unfolded to form a homogeneous three‐dimensional gel network structure after salting, while heterogeneous aggregates were formed to hinder the gel development in DEY. Changes in protein secondary structure content showed that pickling can promote the transformation of the α‐helices to β‐sheets structure in HEY gels, while more α‐helices structure was formed in DEY gels.ConclusionThe study demonstrated that different gelation behaviors of hen and duck egg yolk proteins (especially in plasma) through salting treatment led to the difference in the quality of salted HEY and DEY.This article is protected by copyright. All rights reserved.

Novel Insights into the Effects of Different Cooking Methods on Salted Egg Yolks: Physicochemical and Sensory Analysis

“…Juhaimi et al [6] observed that various cooking methods significantly impact the oil content. According to previous reports, most of the lipids in egg yolk are present in low-density lipoproteins (LDLs) [23]. During saltinduced processing, free lipids may be released from LDL micelles due to changes in LDL structure caused by dehydration and high salt conditions.…”