Quantification of egg yolk contamination in egg white using UV/Vis spectroscopy: Prediction model development and analysis

The objective of this study was to develop a statistical model for predicting egg yolk contamination level in egg white using a spectroscopic method. Eggs that were stored for 0, 0.5, 1.0, 1.5, 2.5, and 6.5wk at 4°C were manually processed to cleanly separate the yolk from the white. Egg white samples containing 0-0.5% (w/w) of yolk were prepared by adding yolk to the white and further diluting with the pure egg white. Transmission spectra of samples were acquired at 500nm wavelength. The optical absorbance of the "contaminated" egg white samples positively correlated with the yolk concentration, and its intensity was affected by the freshness of eggs, egg variety, and measuring temperature. A nonlinear prediction model, or a detection function, was developed using 182 measurements to predict yolk concentration with a known storage time. This highly sensitive method was validated using 102 separate measurements.