Non-destructive assessment of egg freshness using UV-IR spectroscopy and determination of the effective wavelength domain

Therefore، the objective of this study is to test the feasibility of UV-IR transmission spectroscopy for the non-destructive assessment of the freshness of an individual egg as an alternative for traditional inspection methods. To obtain a considerable variation in freshness، groups consisting of 10 eggs were stored (30 7 oC and 25% 4 RH) for 30 days. Data obtained from non-destructive spectral measurements were compared with three destructive freshness parameters including Haugh units (HU)، albumen and yolk pH as well as yolk coefficient (YC(. Partial least squares regression (PLSR) and principal component regression (PCR) models are built in order to predict HU، pH and YC based on the transmission spectra. The correlation coefficients between the predicted value and the measured value are 0. 88، 0. 86 and 0. 78 for HU، YC and pH of the albumen، respectively، in the PLSR method and 0. 64، 0. 62 and 0. 41 for HU، YC and pH of the albumen، respectively، in the PCR method. These results show that the light transmission spectrum of an egg provides better quantitative information about egg freshness based on PLSR method. Effective information concerning egg freshness is restricted to the wavelength interval between 510 and 820 nm.