Xanthan gum produced from milk permeate and deproteinized cheese whey: A comparative analysis with commercial xanthan gums

In this study, we produced xanthan gums from deproteinized whey and milk permeate and evaluated their rheological behavior, FT-IR spectral profiles, thermogravimetric decomposition, and coloration. Besides, commercial xanthan gums were also characterized and employed in a comparative analysis. All xanthan gum exhibited non-Newtonian behavior characterized by a decrease in viscosity with an increase in the shear rate. At a shear rate of 32 s-1, the viscosity values for XGC1, XGC2, and XGC3 were 308.16, 334.64, and 256.16 mPa s, while XGMP and XGDW exhibited viscosities of 146.82 and 77.82 mPa s, respectively. Flow indexes (n) were lesser than 1 confirming a pseudoplastic behavior for all xanthan gums. Greater consistency indices (K) were observed in commercial xanthan gums, reaching values higher than those biosynthesized. Both xanthan gums groups exhibited similar functional groups within the 1800 to 900 cm-1 wavelength regions as determined by FTIR-ATR analysis. However, they showed differences in bands from 800 to 500 cm-1. Principal component analysis (PCA) applied to the spectra effectively differentiated XGC3 from the other xanthan gums. Commercial xanthan gums exhibited similar thermal degradation profiles, characterized by two distinct stages of mass loss, while biosynthesized gums showed three stages. XGDW exhibited lower values for luminosity and whiteness indices compared to other gums. Our findings demonstrated differences in the viscosity, consistency, molecular structure, thermal degradation, and coloration of the evaluated xanthan, even within the group of commercial gums. XGMP stands out among biosynthesized xanthan gums owing to its similarity to commercial gums and its noteworthy characteristics for industrial applications.