Changes in the textural and flavor characteristics of egg white emulsion gels induced by lipid and thermal treatment

Abstract

Egg white (EW) and peanut oil (PO), show good gel and flavor properties and were used to study the effects of lipid and heat treatment on the texture and flavor of emulsion gels. Good emulsification was obtained at low protein concentrations, and extremely high or low protein concentrations were essential for the formation of emulsion gel hardness, whereas the chewiness of emulsion gels with intermediate protein concentrations was sensitive to heat treatment. A new nonflowing proton (H+) from EW and lipid was integrated, and the water and lipids were closely bonded with other macromolecules in EW-PO emulsions. The bound and free water were combined with nonflowing water in emulsion gels due to heat treatment. 2-Methylbenzyl alcohol, octanoic acid ethyl ester, phenol and nicotinyl alcohol were the main flavor components of EW and PO, whereas 3,5-diethyl-2-methyl-pyrazine and 1-methyl-1H-pyrrole-2-carboxaldehyde were produced during the formation of the EW-PO emulsion. The formation of methylene-benzeneacetonitrile, 1H-pyrrole-2-carboxaldehyde, etc., in EW-PO emulsion gels were affected by the proportion of PO. Phthalic acid, benzaldehyde, 2,3-dihydro-benzofuran, 4-bromo-3-chloro-N-(4-methylthiobenzylydene)-benzenamine, 2-aminopyridine, hexanal, heptaethylene glycol monododecyl ether, isophytol and nicotinyl alcohol, etc., were formed in EW-PO emulsion gels. The main and differential flavors of EW-PO emulsions (or gels) may be attributed to EW and peanut oil, and the variation in flavor emitted from peanut oil and EW-PO gels was induced by heat treatment.