Kinetics of aroma formation from grape-derived precursors: Temperature effects and predictive potential

This study investigates the accumulation and degradation of aroma molecules released by acid hydrolysis of aroma precursors in winemaking grapes. A first-order kinetics model effectively interprets this accumulation, including subsequent degradation. Experimentation at three temperatures categorizes specific grape-derived aroma molecules into three stability-based groups: labile molecules from labile precursors, stable molecules from labile precursors, and stable molecules from stable precursors. While many grape-derived aromas exhibit similar patterns and levels of accumulation across temperatures, reaction rates significantly increase with temperature. The analysis of 12 samples of two grape varieties hydrolyzed at 50 °C for 5 weeks and 75 °C for 24 h confirms that fast hydrolysis accurately replicates varietal and between-sample aroma compositional differences. Moreover, the accumulated levels of 21 relevant grape-derived aromas strongly correlate with those at 50 °C, indicating that fast hydrolysis at 75 °C reliably predicts grape aroma potential.