Abstract
The freshness indices of shell eggs are storage time and Haugh unit. Haugh unit is the value derived from the weight of a shell egg and the height of thick albumen and reduces due to carbon dioxide dissipation from the inside. In the present study, Haguh unit and storage time were nondestructively measured using transmission spectroscopy from near ultra violet range to near-infrared range. Each 55 eggs were stored in 3 environments: opened, packed, and exposed to carbon dioxide. Transmission spectrums were measured with 4 combinations of light source and light path every three days. Haugh unit and storage time were predicted from absorbance spectrums in the wavelength range from 500 nm to 950 nm with PLS regression. The prediction accuracy of the PLS model for storage time was high (R=0.966, SEP=2.43 days) . On the other side, the prediction accuracy of the models for Haugh unit was (R=0.867, SEP=10.8) . In both cases, the predicted models using xenon light source which have strong spectrum in the range near 500 nm showed the best accuracy.
