Influence of skin maceration and Torulaspora delbrueckii inoculation on white wine production: changes in fermentation dynamics and wine composition

Identifier:  imarina:9468460

Handle: https://hdl.handle.net/20.500.11797/imarina9468460

Authors:  Ruiz-de-Villa, C; García-Viñola, V; Schorn-García, D; Poblet, M; Bordons, A; Reguant, C; Rozès, N

Abstract:
Innovative approaches in white wine production, including extended skin contact and malolactic fermentation (MLF), are gaining attention for their potential to enhance wine complexity. This study examines how skin contact during alcoholic fermentation (AF), fermentation temperature, and yeast inoculation strategies impact white wine composition, focusing on Torulaspora delbrueckii (Td) behavior. Physicochemical analyses confirmed spontaneous MLF in Td-fermented wines, linked to indigenous Oenococcus oeni. Metabolomic and volatile analysis, through PCA and ASCA, revealed that vinification style was the primary driver of wine composition, specially influencing phenolic acids and Krebs cycle metabolites. Skin-fermented wines showed higher levels of phenolic compounds, especially at higher temperatures. Td fermentation reduced hydroxycinnamic acids, likely improving MLF compatibility. Notably, 2-isopropylmalic acid (2-IPMA) was detected, with higher concentrations in skin-fermented wines at elevated temperatures. Td-fermented wines underwent spontaneous MLF, progressing faster than in controls, likely due to reduced medium-chain fatty acids and increased mannoproteins. These findings highlight the potential of Td to facilitate MLF by improving the biochemical environment for O. oeni, although spontaneous MLF requires careful management. Nineteen O. oeni genotypic profiles were identified, with the M2 profile persisting through AF and spontaneous MLF, and the C5 profile predominating in wines inoculated with OoVP41. Sensory analysis revealed that wines fermented with Td exhibited distinct aromas, such as tropical, pear, and terpenic notes, especially in skin-fermented wines. This work underscores how specific winemaking strategies can modulate fermentation dynamics and wine composition, offering new insights into the role of T. delbrueckii in skin-fermented and white wine production.