NIR cheese-vat monitoring of milk coagulation and curd syneresis in sheep with subclinical mastitis. A preliminary inline study

Subclinical mastitis (SCM) affects milk's optical properties and cheesemaking performance without altering its gross composition. This study evaluated the influence of SCM on milk coagulation kinetics, curd syneresis, cheese yield, and whey composition using inline light backscatter-based measurements and predictive modelling at pilot-plant scale. Although fat, protein, and casein contents did not differ between subclinically infected (various coagulase negative staphylococci) and uninfected ewes´ milks, SCM significantly reduced initial light backscatter (V 0 ), prolonged coagulation, and impaired curd firmness, likely due to casein micelle demineralization and enzymatic degradation. Large field of view (LFV) sensor data revealed accelerated and enhanced syneresis in subclinically infected milks, correlating with increased whey expulsion and lower cheese yields. Strong correlations were observed between somatic cell counts and optical coagulation indicators (R 2 = 0.97–0.99, P < 0.01). Predictive models validated from previous studies accurately estimated cutting times (R 2 = 0.94–0.98), while new algorithms incorporating optical and compositional parameters effectively predicted cheese composition, yield, and whey properties (R 2 up to 0.998). These findings confirm that optical sensing technologies, combined with multivariate regression, offer powerful tools for real-time monitoring and prediction of cheesemaking parameters, even in milk compromised by SCM.