PROTEIN DEGRADATION IN CHEDDAR CHEESE SLURRIES

SUMMARY— Preferential degradation of caseins was noted in the ripening of Cheddar curd slurries, with the degradation generally being in the order of para-K, β-, α_s-caseins. The addition of reduced glutathione to the slurry caused an immediate release of peptides from the protein mass and decreased the initial rate of β-casein degradation. The peptides appeared to be preferentially utilized during the first 4 days of ripening; thereafter rapid degradation of β-casein occurred. In quiescent slurries, α_s-casein degradation exceeded that of β-casein, whereas periodic agitation reversed the degradation rate of the two caseins. The rate and extent of characteristic flavor development appeared to be related directly to β-casein degradation, but not to changes in concentration of pare-K or α_s-caseins.