Rapid determination of egg yolk contamination in egg white by VIS spectroscopy

• UV–Vis spectroscopic screening was developed to detect yolk contamination in egg white at 0.001 wt%.
• Two wavelengths were identified to be sensitive to yolk contamination at 430 nm and 378 nm.
• A quantitative predictive model was developed which took into account the influence of measuring temperature.
• The method potentially can become an in-line monitoring method for detecting yolk contamination in egg white.

In this study, a non-invasive method utilizing VIS spectroscopy for rapid and quantitative determination of yolk contamination in egg white was developed. Fresh eggs were obtained from Iowa egg production facilities and were used to prepare 210 egg white samples with various levels of yolk contamination. The simulated yolk contamination levels ranged from 0.001 to 0.1 wt% in egg white (as-is basis), and the samples were subjected to spectroscopic analysis. UV–Vis–NIR spectra (200–860 nm) were acquired for each sample with a spectral resolution of 2 nm. The absorption bands at 430 nm and 378 nm were identified as the most sensitive to the yolk contamination. A quantitative predictive model was developed to correlate the two absorptions to the concentration of yolk contamination. The correlation coefficient of calibration set and validation set are 0.9830 and 0.9769, respectively. The MSE (mean squares error) of calibration set and validation set are 0.0066 and 0.0044%, respectively. The UV–VIS spectroscopy method was demonstrated to be sensitive at as low as 0.001% yolk content. It can potentially become a simple, noninvasive, and rapid and yet highly sensitive routine test as a quality control means for egg processing industry.