Atypical ageing defect in Pinot Blanc wines: a comparison between organic and conventional production management systems.

Background: Atypical ageing (ATA) is an aroma defect that occurs in white wines and entails a loss of varietal aromas as well as scents of wet mop, shoe polish and dish rag. 2-Aminoacetophenone (2AAP) - a degradation product of indole-3-acetic acid (IAA) - has been described as the main odour-active compound and chemical marker responsible for this off-flavour. A stress reaction in the vineyard triggered by climatic, pedological and viticultural factors can ultimately cause ATA development in wines and remarkably affect wine quality. The aim of this research was to investigate the influence of three grapevine management systems on the occurrence of ATA. The experiments were carried out on Pinot Blanc grape samples from vines cultivated using one conventional and two organic approaches. The management systems mainly differed for the fertilisation regime and the weed control.

Results: The amino acid profiles as well as 2AAP and its precursors were quantified in musts and wines using ultra-high-performance liquid chromatography coupled to a high-resolution mass spectrometer. The results showed the existence of a strong vintage effect, while no influence of the use of different agronomic systems was observed.

Conclusion: The study revealed that an efficient implementation of different grapevine production systems did not affect ATA development in Pinot Blanc wines. This finding is of great relevance for winegrowers and winemakers as it demonstrates that a well-planned organic management system correctly adjusted to the climatic conditions does not pose a threat towards the development of ATA-related compounds in wine. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.