Enhancing the Antimicrobial Properties of Gouda Cheese Wax Using Chitosan-Silica Nanocomposite Coatings

Gouda cheese, a popular semi-hard cheese enjoyed worldwide, depends on wax coatings to preserve quality during ripening and storage by limiting moisture loss and microbial contamination. This study developed a chitosan-silica nanocomposite coating to bolster the antimicrobial properties of Gouda cheese wax, aiming to improve food safety and prolong shelf life. The approach involved blending chitosan with silica nanoparticles (nanoclay) to form a nanocomposite wax. The research was performed in two stages: first, testing nanocomposite films with varying compositions, pinpointing an optimal mix of 3 wt% chitosan and 1 wt% nanoclay; second, applying this coating to Gouda cheese and assessing it over 180 days for microbial, sensory, and physicochemical outcomes. The findings exhibited that the nanocomposite coating decreased microbial growth, reducing mold and yeast counts by 99.9% (p< 0.01) and dropping E. coli levels to 0.36 MPN/g by day 180, compared to 21 MPN/g in regular wax-coated controls (p<0.05). Sensory tests showed notable improvements, with coated cheese earning a taste score of 3.52 ± 0.11 versus 2.33 ± 0.12 for controls on day 180. On the physicochemical aspect, coated cheese maintained higher moisture at 48.33% (vs. 45.14% in controls) and experienced less weight loss (14.64% vs. 19.76%). The nanocomposite film itself, with a thickness of 0.61 ± 0.015 mm and water vapor permeability of 1.88 × 10⁻¹⁰ g/m·s·Pa, proved highly effective. This innovation offers a sustainable upgrade over traditional wax, with wide potential for cheese preservation.