Application of IR spectroscopy for the assessment of egg and egg product quality

Infrared (IR) spectroscopy is rapidly expanding in various fields. The interest in this spectroscopic technique, in particular in the near infrared (NIR) range, lies in its advantages over alternative instrumental methods (e.g. rapidity, easiness, cheapness). It can analyze both solid and liquid samples with no pretreatment, providing spectra which are used to predict physical and chemical parameters. Thus, IR spectroscopy, combined with chemometric analysis, is increasingly acknowledged also as a useful tool for the food quality and genuineness assessment. However, the use of this technique in the field of eggs and egg products seems to be little attempted so far. This paper is aimed at reviewing and discussing the works reported in the literature on NIR applications on eggs. Some of those concern the possibility of evaluating egg quality and freshness, as well as egg product composition. In other works the IR spectroscopy has been used for studying the denaturing effects of heat treatment on albumen proteins or evaluating the egg amount in fresh pasta. To the best of our knowledge, no work has been addressed to the study of the egg product technological properties by means of NIR spectroscopy. Thus, preliminary results of a research aimed at studying the gelling properties of dried egg albumen will be also illustrated.