Diversity of Volatile Aroma Compound Composition Produced by Non- Yeasts in the Early Phase of Grape Must Fermentation.

There is a lack of studies evaluating the metabolic contribution of non- yeasts in early fermentation phases. This study aimed to investigate the volatile aroma profiles produced by various non- yeasts just before sequential inoculation with to provide an insight into the particular effects they induce at this stage. The grape must of Malvazija istarska was inoculated with monocultures of , , , , and , alongside a control. Eighty volatile compounds were quantified via headspace solid-phase microextraction and gas chromatography-mass spectrometry, and the data were statistically elaborated. Volatile profiles of non- yeasts differed significantly from the control. Most treatments caused increases in linalool and β-damascenone, decreases in higher alcohols and fatty acids, and improved synthesis of odoriferous esters. and produced compounds not commonly found in fermented wines. Multivariate statistical analysis linked the investigated yeasts to specific, particularly abundant compounds. Future studies should explore to what degree these contributions persist after sequential inoculation with in diverse grape must matrices.