The effect of sodium- or potassium-based emulsifying salts on the physicochemical, mechanical, thermal, and sensory properties of processed cheese: A comparative study

Reducing the sodium content in processed cheese (PC) is a major nutritional goal, whereas maintaining its functional and sensory quality remains challenging. The current study evaluated the impact of potassium-based emulsifying salts (ES; dipotassium hydrogen phosphate, DKP; tetrapotassium pyrophosphate, TKPP; pentapotassium triphosphate, KTPP) at different concentrations (2.0%, 2.5%, and 3.0% wt/wt) on the physicochemical, mechanical (viscoelastic, textural, and mechanical vibration damping), thermal, and sensory properties of model PC samples (40% wt/wt DM and 50% wt/wt fat in DM contents) during a 60-d storage period at 6°C ± 2°C. Selected types of sodium-based ES (disodium hydrogen phosphate, DSP; tetrasodium pyrophosphate, TSPP; pentasodium triphosphate, STPP) were also prepared for comparison reasons. All tested samples exhibited a gel-like, predominantly elastic behavior, with functional responses dependent on ES type and concentration. Hardness increased with longer (potassium or sodium) phosphate chains: DKP (or DSP) < TKPP (or TSPP) < KTPP (or STPP), with KTPP producing the firmest PC samples. Mechanical vibration damping measurements were consistent with hardness and complex modulus (G*) results. In addition, storage period slightly decreased samples' pH and yellowness. The results of the differential scanning calorimetry indicated enhanced water binding with higher potassium content. Furthermore, the use of potassium-based ES significantly lowered sodium levels in the resultant PC without compromising sensory quality. The obtained results highlighted that potassium-based ES could be considered as a beneficial alternative to sodium-based ES, offering an effective strategy to reduce dietary sodium intake while preserving key functional and sensory properties of PC.