Predicting cheese quality as early as possible after ripening is important for quality control in the cheese industry. The main aim of this study was to investigate potential metabolites for predictive models of Cheddar cheese quality. Metabolites in aqueous extracts of Cheddar cheese were identified by Nuclear Magnetic Resonance. The metabolites were used to measure the kinetics of up to 450 days ripening in Cheddar cheese. The proton ratios of citrulline and arginine relative to the overall proton content of the aqueous extract are the most important indices for assessing the ripening of Cheddar cheese. The ratios of citrulline and arginine decrease by 59% and 69%, respectively, after 450 days ripening. In comparison to the premium batch B cheese, batch C which was predicted to attain a lower quality level, had higher serine and β-galactose as well as lower lactic acid levels and also had a less mature sensorial profile. Tyrosine, tyramine and lysine are highly correlated with mature Cheddar cheese sensory attributes. β-Galactose and glycerol are correlated with young Cheddar cheese sensory attributes. These metabolites can be used to predict cheese quality.

Cheddar cheese predicted to develop into different quality classes has been evaluated by time domain Nuclear Magnetic Resonance, Thermogravimetric analysis and quantitative sensory analysis. The water and fat proton signals in the transverse relaxation decay curves have been deconvoluted. Proton transverse relaxation values for both the water and fat fractions decrease and the relative %age of the proton peak area, predominantly from the fat increases over a 450-day ripening period. The thermodynamic free water percentage increases during maturation. Water and fat attributes can distinguish between Cheddar cheese batches after 56 days. Cheese batches which have lower transverse relaxation values for the water and fat proton fractions and a higher relative %age of the proton peak area predominantly from fat at 56 days, mature after 270 days to be more yellow, rubbery and smooth, have a less sour and lingering aftertaste and are also harder to form into a cheese ball.