Fluorescence spectroscopy as a non destructive method to predict rheological characteristics of Tilsit cheese

- Potential of fluorescence spectroscopy to predict rheological and physico-chemical properties of semi-hard cheeses.
- Tryptophan emission, vitamin A emission and excitation spectra were processed with multivariate statistical tools.
- High potential of fluorescence spectroscopy in predicting rheological properties and composition of Tilzit cheese was shown.

The objective of this study was to investigate the potential of fluorescence spectroscopy to predict rheological characteristics of semi-hard cheeses as yield stress (τL), flow stress (τF), storage modulus (G′) and loss modulus (G″) measured at linear-viscoelastic, yield stress and flow stress oscillation regions. Melting temperatures and chemical composition of the semi-hard cheeses were also predicted using fluorescence spectra. Principal component analysis (PCA) and partial least squares regression (PLSR) were applied to the fluorescence spectra to extract information on the rheological properties, chemical composition, and melting temperatures. τL and τF were predicted with R2 = 0.90 from the vitamin A emission and excitation spectra, respectively. Melting temperatures, moisture, protein and fat contents were predicted with R2 = 0.98 from the vitamin A emission spectra. This study demonstrates that fluorescence spectroscopy has potential for the accurate, non-destructive and rapid prediction of cheese rheology at linear-viscoelastic, yield stress and flow stress oscillation regions simultaneously.