Camilla Varming

Aroma changes from raw to processed products in fruits and vegetables

Abstract The present paper deals with aroma changes in the production and storage of precooked potatoes, frozen leeks and fruit juices (apple and blackcurrant). In precooked potatoes and frozen leeks development of aliphatic aldehydes results in off-flavours, however, blanching (leeks) and exclusion of oxygen reduce off-flavour formation. In fruit juices high losses of esters and terpenes in the different processing steps are seen and result in juices of poor aroma quality with losses of 80 to 90% of the aroma volatiles. The aroma losses and changes are results of enzyme activity, thermal influence, evaporation and removal by water or waste.

Aroma Analysis and Data Handling in the Evaluation of Niche Apple Juices from 160 Local Danish Apple Cultivars

Old Danish apple cultivars might have potential in the production of speciality apple juices with unique flavor qualities. In the present study, aroma analysis was performed on juices from 160 local apple cultivars. Chromatographic data treatment challenges in the analysis of this large number of samples with very different volatile profiles were overcome with PARAFAC2 and PCA. The main compound groups identified were acetate esters, butanoate esters, and alcohols, and there were large differences in the aroma profiles of the juices of the different apple cultivars.

Glycosidically bound alcohols of blackcurrant juice

Abstract The release of bound volatile alcohols of blackcurrant juice from the corresponding glycosides was studied enzymatically using β-glucosidase in two different ways. The enzyme was added either directly to the juice, or to an extract of glycosidic compounds that had been isolated from the juice by chromatography using Amberlite XAD-2. The two methods resulted in the same patterns of released volatile aglyconic compounds. Fifteen aliphatic alcohols, four aromatic alcohols and one aromatic aldehyde were identified in the glycosidically bound fraction.

Post-harvest ripening increase cultivar specific sensory and analytical aroma profile in apple juice: A study of four commercial cultivars in Denmark

Apples are normally produced with focus on the fresh fruit marked, which imply high priority on storability and shelf life. The fruits used for juice are normally those discarded along the post-harvest chain. If the main goal is changed to production of high-quality juice with emphasis on single cultivar characteristic flavours, focus can be on optimal fruit ripening for flavour development. To investigate the juice quality potentials during post-harvest ripening, four apple cultivars: ‘Aroma’, ‘Holsteiner Cox’, ‘Ingrid Marie’ and ‘Rajka’ were sampled and juiced after 5 and 10 days of post-harvest storage at room temperature (20°C). The soluble solids content (SSC) of ‘Ingrid Marie’ fruits increased most, and after 10 days, it had the lowest starch content of the four cultivars studied. The mid-to-late season cultivars ‘Ingrid Marie’, ‘Holsteiner Cox’ and ‘Rajka’ had higher SSC/acidity ratio than the middle early season ‘Aroma’ ‘and all of them showed an increase of the ratio SSC/acidity during storage’. The volatile compound measurements (GC-MS) of the juices indicated that particularly ‘Holsteiner Cox’ and ‘Ingrid Marie’ have the ability to produce fruity volatile compounds like ethyl acetate, propyl acetate, 2-methylpropyl acetate, butyl acetate, hexyl acetate, hexanal, ethyl propanoate, pentyl acetate and ethyl 2-metylbutanoate exhibiting remarkable changes during ripening. These volatile compounds may explain the post-harvest development of interesting fruity nuances perceived by the sensory panel. The terms ‘apricot’, ‘peach’ and ‘pineapple’ were used to describe the odour and flavour properties of these cultivar juices in the sensory analysis. ‘Aroma’ apples ranked high on ‘citrus’, ‘red berries’ and ‘pear’ flavour descriptors after 5 days of storage, whereas ‘Rajka’ showed the weakest aroma profile of the group of cultivars. To exploit the aroma and sensory potential fully, apple cultivars should be further investigated in regards to effects of delayed harvest and different post-harvest treatments.