Application of dietary fibers as hydrocolloids: Experimental evaluation in a model processed cheese sauce system

Abstract

This study investigates the impact of dietary fibers (beetroot or carrot) on the surface texture, rheological behavior, and stability of processed cheese sauces made with different fat sources: anhydrous milk fat (AMF), organic coconut oil (OCO), or rapeseed oil (RO). Surface roughness (R_a, R_q, R_t) was analyzed using optical profilometry, and emulsion stability was evaluated via Turbiscan Stability Index (TSI). Optical microscopy enabled qualitative assessment of droplet distribution, while rheological parameters—storage modulus (G′), loss modulus (G″), and viscosity—were measured alongside instrumental texture properties (hardness, adhesiveness, cohesiveness). Results showed that both fiber type and concentration significantly influenced all analyzed parameters. Beetroot fiber at 1 % in OCO-based sauces produced the highest surface roughness, which decreased at 4 % fiber concentration, indicating improved homogenization. Carrot fiber at 4 % also contributed to a smoother surface. TSI revealed highest instability in AMF-based samples with 3 % carrot fiber, while 4 % fiber improved stability. A correlation was found between surface roughness and instability. AMF-based samples displayed the highest G′, suggesting a more robust elastic network, with beetroot fiber enhancing elasticity more effectively. All fiber-enriched sauces showed shear-thinning behavior, with highest viscosity observed in AMF-based sauces containing 4 % fiber. Texture analysis confirmed that increasing fiber concentration enhanced firmness and cohesiveness. Overall, fiber type and concentration, along with fat source, are key to optimizing the structural and functional properties of processed cheese sauces, supporting the formulation of fiber-enriched emulsified foods.