Xanthan gum production from sugarcane bagasse and its potential for biodegradable food packaging films

Growing environmental concerns over plastic pollution have intensified the search for sustainable alternatives in food packaging. However, the high cost of biopolymers remains a barrier to large-scale adoption. This study addresses this gap by investigating the use of sugarcane bagasse, an abundant agro-industrial residue in Minas Gerais (Brazil), as a low-cost substrate for xanthan gum (XG) production. The objective was to evaluate the physicochemical properties of lab-produced XG and compare them to commercial XG, assessing their suitability for incorporation into biodegradable packaging films. In this sense, the developed gum was characterized for apparent and intrinsic viscosities, molecular weight, chemical/functional groups (FTIR), thermal properties (TGA and DSC), and elemental analysis (C, H, O, N and S). Fermentation of sugarcane bagasse extract (6 % w/v) with Xanthomonas campestris CCT 5268 at 28 °C for 120 h yielded 2.07 g/L of gum. The biopolymer exhibited pseudoplastic behavior, with an apparent viscosity of 135 mPa·s at 25° C and 25 s⁻¹ . Thermal analysis revealed degradation temperatures of 290º C (lab-produced) and 300º C (commercial), indicating comparable stability. The molecular weight of the lab-produced gum was 1238 kDa, surpassing the commercial sample (1018 kDa). FTIR and elemental analyses confirmed structural similarity between both samples, with minor differences attributed to the fermentation substrate. These findings demonstrate the feasibility of valorizing agro-industrial waste for the production of functional biopolymers, supporting the development of cost-effective and sustainable packaging materials.