Abstract

Metabolic processes taking place in harvested crops can be monitored by recording the emission rates of certain volatile metabolites. Under anoxic conditions, fermentation is the main source of energy for the crop, leading to the emission of acetaldehyde and ethanol. Dynamic responses of the crop to e.g. a changing atmosphere are particularly well studied with a laser based photoacoustic trace gas detector thanks to the combination of high sensitivity and high time resolution. Here we present our latest results on such dynamic effects during fermentation in several products, mainly pears and bell peppers. As an example, the acetaldehyde response of a red bell pepper to transitions to anoxia and to post-anoxia are shown in figure 1.

© 1998 IEEE