Variation in Oat Groats Due to Variety, Storage and Heat Treatment. II: Sensory Quality

A sensory profiling analysis of heat-processed oats (Avena sativaL.) was performed. The oat grains were of three varieties (Kapp, Mustang and Svea), stored at different relative humidities (30, 55 or 80%) for 3·5 or 15·5 months and heat-treated either with or without prior dehulling. The main differences in sensory attributes were related to the various thermal processes. Processed dehulled samples, particularly of theMustangvariety, had the highest intensities of oat odour, oat flavour, fresh odour and fresh flavour. Samples processed with hulls, in particular the varieties Kapp and Svea had the highest intensities of odour and flavour, rancid odour and flavour and bitterness. The sensory profile of processed oats were described partly by variations in phenolic compounds of low molecular weight, fat acidity and moisture content after processing. Twenty-nine per cent of the variation in odour and flavour attributes was explained by the 11 phenolic compounds analysed. Water content and the phenolic compoundsp-coumaric acid, vanillin,p-hydroxybenzaldehyde and coniferyl alcohol were significantly correlated (P<0·05) to high levels of rancidity, flavour intensity and bitterness and low levels of freshness, oat odour and flavour. The avenanthramides were related mainly to low levels of flavour intensity and rancid odour and flavour. Caffeic acid and fat acidity were related to low intensities of sweetness and aftertaste.