The Flavour of Old Apple Varieties

Styria is Austrian’s apple cultivation hot spot. About 80% of the annual harvest (corresponding to about 130.000 tons) are harvested in this region. The majority of the apples – mainly new apple varieties as Golden Delicious, Gala or Idared - are cultivated in plantations. However, about 25% of the apples are grown in so-called meadow orchards. These meadow orchards represent an enormous pool for apple varieties – mainly old apple varieties (Maschanzker, Kronprinz Rudolf, Bohnapfel and many more) that have been traditionally grown there. In many cases these varieties show completely different properties than fruits from new varieties. Even though these varieties have been cultivated in this region for many decades, the flavour properties are not described. For most varieties, a molecular characterisation of the flavour compounds is lacking. The aim of the PhD thesis is to characterize and understand the flavour of old apple varieties by using several different techniques delivering complementary information:

1. Gas chromatography-mass spectrometry GC-MS and Comprehensive GC-MS (GC x GC-MS)
2. Gas chromatography-olfactometry GC-O
3. New techniques of sensory analysis.

The complete sensory characterisation is going to be performed by using an expert panel of the intact as well as of the sliced apples after enzyme inactivation. New techniques of sensory evaluation methods will be used for the complete characterisation of the old apple varieties. The combination of these complementary techniques will hopefully allow to decode the flavour of selected apple varieties and broaden the understanding of apple flavour formation.