Identification of compounds contributing to boiled potato off-flavour ('POF')

Abstract

Boiled potato off-flavour is a cardboard-like note, that develops within hours when boiled potatoes are stored. Using a panel of four professional judges, it was verified that a clearly detectable off-flavour develops during the storage of boiled potatoes. Two different isolation methods (direct extraction and vacuum distillation / extraction) in combination with GC-MS and GC-sniffing were applied to the same freshly boiled and stored boiled potatoes. Eight compounds, (pentanal, hexanal, nonanal, (E)-2-octenal, 2,4-heptadienal, (E)-2-nonena, (E,E)-2,4-nonedienal and 2,4-decadienal) were appointed as potential contributors to the off-flavour, since these compounds could be detected during GC-sniffing, and increased in concentration during storage. The eight compounds, that most probably appear as a result of lipoxygenase initiated oxidation of linoleic and linolenic acid during the boiling process, were quantified in freshly boiled and stored boiled potatoes.