Determination of yolk contamination in liquid egg white using Raman spectroscopy

Area of Science:

• Food Science and Technology
• Analytical Chemistry
• Spectroscopy

Background:

• Egg white's foaming properties are vital for baked and confectionary products.
• Yolk contamination, even at 0.01%, significantly impairs egg white's foaming ability.
• Accurate detection of yolk contamination is essential for quality control in egg processing.

Purpose of the Study:

• To investigate the efficacy of Raman spectroscopy for detecting yolk contamination in egg white.
• To evaluate the molecular optical properties of egg white with varying yolk contamination levels.
• To develop a predictive model for quantifying yolk contamination using spectral data.

Main Methods:

• Preparation of egg white samples with controlled yolk contamination (0-0.25%).
• Acquisition of Raman spectra (250-3,200 cm⁻¹) using a 785 nm laser.
• Data preprocessing including baseline correction and normalization.
• Development of a partial least squares regression (PLSR) model for predicting contamination levels.
• Validation of the model using a separate dataset.

Main Results:

• Raman spectra exhibited distinct features influenced by yolk contamination.
• Key spectral regions (1,080 and 1,666 cm⁻¹) were identified as critical for detection.
• The PLSR model achieved high accuracy, with R² = 0.90 in the validation set.
• The method demonstrated sensitivity to low levels of yolk contamination.

Conclusions:

• Raman spectroscopy is a capable technique for detecting low-level yolk contamination in egg white.
• The developed PLSR model provides a quantitative measure of contamination.
• This technology holds potential for on-line quality control systems in egg processing plants.