Research note: Application and validation of RP-HPLC for quantifying ovomucoid, lysozyme, ovotransferrin, and...

Pasteurized egg white is widely used in the food industry for its high microbiological safety, ease of handling, and versatile technological properties. However, heat-induced protein denaturation during pasteurization can affect its foaming, gelling, and emulsifying functionality. The present study aimed to validate a reversed-phase high-pressure liquid chromatography method for the simultaneous quantification of four major egg white proteins in commercial pasteurized samples, including ovomucoid, lysozyme, ovotransferrin, and ovalbumin. Ten cartons of commercial pasteurized egg white from different brands underwent chromatographic testing, with multiple aliquots analyzed over five consecutive days. The method demonstrated excellent repeatability and reproducibility across all proteins, with ovotransferrin and ovalbumin showing the best performances. Recovery rates ranged from 90.67% for lysozyme to 114.10% for ovomucoid, both at the medium spiking level. Method linearity was assessed using ten serial dilutions of pasteurized egg white in water (1:20 to 1:100). Linear regression of peak areas versus nominal protein concentrations yielded correlation coefficients above 0.99 for all target proteins, confirming a strong proportional response. Concentration of ovomucoid, lysozyme, ovotransferrin, and ovalbumin averaged 15.23, 2.23, 13.50, and 71.80 mg/mL (respectively), which suggests minimal impact of pasteurization on the egg white protein composition. The chromatographic method validated in the present study provides a reliable and practical tool for both research and industrial applications, enabling accurate monitoring of protein composition in commercial pasteurized egg white.