Changes in some nitrogenous constituents of potato tubers during aerobic autolysis

Potato tubers of four cultivars were ground and allowed to undergo aerobic autolysis. Tubers were fractionated before and after autolysis, and distributions of dry matter, N and of free and bound amino acids measured. “Chemically available lysine” and chlorogenic acid were also determined. Extent of “enzymic browning” correlated with loss of free tyrosine but not with “chemically available lysine” content. This last may have been influenced by enzymic oxidation of chlorogenic acid. Losses of S‐containing amino acids were observed. Free 4‐aminobutyric acid increased and free glutamic acid decreased, suggesting α‐decarboxylation of the latter.