Translated abstract:
Commercially available apple juices are usually “juices from concentrate (JFC)”. To reduce the costs for transport, and also to maintain the availability of apple juice independently from the harvesting time, water and aroma is removed by steam distillation of the fresh juices. The concentrate and the aroma are then used to manufacture JFC juices by the juice producers. Enzymatic reactions as well as the thermal treatment may lead to changes in the key odorants of the fresh apple juice. By application of the “molecular sensory science” concept, changes induced by each single step of juice processing were clarified on a molecular basis and recommendations for aroma optimization could be proposed. The enzymatic generation of C-6 aldehydes before pasteurization as well as the thermal generation of
(E)-β-damascenone were the most important changes in the molecular aroma profile.