Production of Kashar cheese (a pasta-filata cheese) using reverse osmosis milk: Effects on yield, physical and microstructural properties

The concentration of milk by reverse osmosis membranes (RO) can provide a sustainable cheese production by reducing milk volume and consequently reducing transport cost and carbon dioxide emission, and increasing production yield. Higher amounts of lactose and minerals, responsible for textural defects in cheese made by RO, can be diminished in the scalding and kneading steps of pasta-filata type cheese manufacture. This study aimed to evaluate the meltability, rheological and textural properties of Kashar cheese (a pasta-filata type cheese) produced by 1× milk (control), and 1.5× and 2× RO-retentates. The 1.5× RO-cheese had 8 % higher moisture-adjusted yields than the control, increasing to 21 % for the 2× RO-cheese. No significant differences were observed between experimental and control cheese for pH and protein (%). However, experimental cheese showed significantly lower values for moisture and salt/DM (%) and significantly higher values for ash and fat/DM (%) compared to control cheese. Among the control and experimental cheeses, the highest Schreiber meltability test scores and maximum loss tangent values were observed in the control, followed by 1.5× cheese, with 2× cheese showing the lowest values. In contrast, hardness and springiness exhibited an inverse trend, being highest in 2× and lowest in control cheese. The compact and thick protein fibres of 2× cheese identified through microstructure analysis provided explanatory insight into its textural and rheological behaviour. These results demonstrated that 1.5× RO retentates significantly improve production efficiency in Kashar cheese manufacture while maintaining desirable meltability and textural properties.