Our studies on flavour have initially concentrated on cooked potatoes with particular emphasis being given to examining the inter-relationships between the chemical composition of potato volatiles released post boiling and the flavour characteristics reported by taste panels. The unique availability of novel potato species with potentially desirable taste attributes is also being exploited in these studies.

The results of taste panel studies undertaken in collaboration with the Hannah Research Institute revealed that boiled potato tubers from Solanum phureja lines had better taste characteristics than the more traditional S. tuberosum cultivars. Although taste and flavour are a highly complex issue involving both volatile and non-volatile components the identification of such diversity in organoleptic characteristics has offered an unique opportunity to study and to identify some of the key chemical components and mechanisms involved in flavour development.

Entrainment tube - Containing Tenax as the absorbent

Initial studies at SCRI have concentrated on the development of appropriate techniques for the entrapment and identification of the volatile compounds released from boiled tubers of both species. The methodology developed incorporates a combination of entrainment of the volatiles by the use of porous polymers such as Tenax as absorbants and their subsequent release and identification using thermal desorption combined with gas chromatography-mass spectrometry.

Schematic of GC-MS setup

Using this methodology, over 80 compounds have been detected in the head-space of boiled potatoes, 70 of which have been identified. A number of these volatile compounds would appear to be unique to S. phureja as well as major differences in the relative amounts of other compounds being detected. However further studies are required to determine whether these differences can be directly related to the originally perceived differences in flavour between the two potato species.  Studies have also been commenced to evaluate the relative importance of enzymic and auto-oxidative reactions in the production of lipid-derived volatiles, which often account for well over 50 per cent of the total volatiles released by boiled potatoes post-cooking.