Volatile production and fruit quality during development of superficial scald in Red Delicious apples

Abstract

To evaluate potential differences in quality between normal and scald-developing apples, volatile components and tissue integrity of Red Delicious apples were analyzed. Solid-phase micro-extraction (SPME) of head-space volatiles coupled with GC-MS (gas chromatography-mass spectrometry) revealed the presence of several fatty acyl esters and the terpene, α-farnesene. Development of superficial scald in Red Delicious apples was not associated with any major qualitative changes in volatiles. However, unscalded Red Delicious apples evolved much higher amounts of volatiles such as hexyl acetate, butyl hexanoate, propyl octanoate, hexyl hexanoate and α-farnesene. Proton magnetic resonance imaging of scalded Red Delicious apples revealed an increase in the mobility of water protons or an increase in the ratio of free to bound water in the epidermal layer and peripheral cortical tissue. The results show that scald development may be associated with changes in volatile emission and tissue integrity in Red Delicious apples.