Development of off-flavour in non-melting flesh peach genotypes

Studies performed to investigate the development of off-flavour in some NMF peach genotypes revealed that there were certain chemical components that were consistently associated with the disorder. Generally there was a signi ficant increase in total soluble phenolics, polyphenoloxidase (PPO) activit y and ethanol with an increase in both the percentage of off-flavoured frui t and the degree of off-flavour with time in storage at 8 degrees C in NMF genotypes. Total soluble sugars and soluble solids decreased significantly during the storage period. These changes in chemical composition of NMF gen otypes were not observed in MF and NMF genotypes that did not show off-flav our development. Highly significant linear correlations were detected betwe en off-flavour development and soluble phenolics, PPO activity, ethanol, to tal soluble solids and soluble sugars in Fla 92-21C and USDA 87P285, lines with the highest percentage of off-flavoured fruit. Soluble phenolics, chlo rogenic acid, PPO activity and ethanol were positively correlated but solub le sugars and soluble solids were negatively correlated with off-flavour de velopment. The accumulation of soluble phenolics and ethanol and the reduct ion in soluble solids and sugars appear to be associated with the developme nt of off-flavour in NMF peach genotypes. (C) 2000 Society of Chemical Indu stry.