Flexcube as an alternative aging vessel to the oak barrel: insights into flavor, oxygen, and matrix interactions

Flexcube, as an alternative aging vessel, has attracted increasing attention for its potential to replicate the effects of traditional oak barrels. This study employed GC-MS, HPLC-MS, spectrophotometer, and multivariate analysis to investigate how aging vessel type (Flexcube and oak barrels) and wine matrix composition (high and low polyphenol content) influence the evolution of volatile compounds, polyphenols, and sensory characteristics during wine aging. Results showed that non-oak-derived aroma compounds remained largely stable across vessels, while oak-derived volatiles such as oak lactones and furanic derivatives were significantly lower in Flexcube. Polyphenol levels were comparable across different aging vessels, with Flexcube-aged wines showing lower monomeric anthocyanin concentrations, while still maintaining relatively deep color in wines with both high and low phenolic content. The development of aroma and phenolic compounds varied with matrix composition, with flavanols and flavonols in high polyphenol content wines exhibiting greater sensitivity to oxygen exposure. Although Flexcube differs from oak barrels in compound evolution during aging, its oxygen permeability can be tailored to match that of oak barrels. When paired with suitable oak adjuncts, it has the potential to simulate oak barrel aging, making it a promising alternative. This study systematically evaluates the aging effects of Flexcube on wines with different polyphenolic matrices, providing a theoretical basis for the scientific application of Flexcube and its stylized aging strategies.