Submitted to: Journal of Food Measurement and Characterization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2013
Publication Date: 7/20/2013
Citation: Hawkins, S.A., Jones, D.R. 2013. Chemometric correlation of shelf life, quality measurements, and visible-near infrared spectra of pasteurized eggs. Journal of Food Measurement and Characterization Journal of Food Measurement and Characterization. DOI:10.1007/s11694-013-9144-5.
Interpretive Summary: Forty-two dozen non treated and forty-two dozen pasteurized eggs were studied over a twelve week period. They were kept refrigerated during storage, prior to the experiments. Every two weeks, beginning with week 0, six dozen of each type were selected and the following measurements were collected: total egg weight, thick albumen height, and visible/near infrared spectra of the homogenized albumen. From these data, the quality measurement known as Haugh Units (HU) was calculated and both the shelf time and HU data were analyzed with the spectral data to determine if correlation exists. The spectral data correlates very well with the storage time. The analysis of the spectra with the Haugh units results in much lower correlation coefficients for pasteurized eggs than non-pasteurized eggs.
Technical Abstract: A twelve week study was conducted on the egg albumen from both pasteurized and non-pasteurized shell eggs using visible-near infrared spectroscopy. Correlation of the chemical changes detected in the spectra to the measurement of Haugh units (measure of interior egg quality) was carried out using principal component regression analysis. Additionally, the study sought to determine how pasteurization affects both shelf life and egg quality. Eighty-four dozen eggs were involved in this study, with 12 dozen eggs scanned initially and biweekly for the remainder of the study. Several quality physical measurements were conducted followed by the Visible/Near Infrared spectra of the albumen. The spectra of untreated eggs are easily distinguishable from those of pasteurized eggs in the visible region. The changes in the spectra over the 12 week period were very subtle. Both untreated and pasteurized eggs had a decrease of approximately 10% transmission during the twelve weeks. Changes in the peak position or shape was more easily detectable by taking the first derivative of the spectra before using principal component regression analysis. The results suggests that spectral data can be used to confirm and/or predict the shelf life of eggs. To a lesser extent the spectra can be correlated to the Haugh Units of non-pasteurized eggs.