Abstract
Exposure of milk to light leads to photooxidation and the development of off-flavours. To follow these reactions, semi-skimmed (1.5% fat) and whole (3.8% fat) extended shelf life (ESL) bovine milk samples were exposed to fluorescent light for up to 20h at room temperature, and the volatiles in the samples' headspace were measured in real time using proton-transfer-reaction mass spectrometry (PTR-MS). Compounds tentatively identified as methanethiol, acetone/propanal, pentanal/octanal/nonanal/1-octen-3-ol, hexanal, diacetyl, dimethyl disulphide, heptanal and benzaldehyde displayed dynamic release profiles relating to the changes occurring in milk upon exposure to light. Copyright (c) 2014 John Wiley & Sons, Ltd.