LAUSR

Abstract Background The overall quality of red wine is well known to be influenced markedly by various phenolic compounds that are extracted from the grape solids during maceration. The concentration and composition of phenolics then impact the flavour and mouthfeel of wines. Scope and Approach This review analyses the available literature on specific process variables that influence the diffusive mass transfer and evolution of phenolic compounds during red wine maceration. These variables are discussed in terms of techniques and strategies used by winemakers to influence the extractive behaviour of phenolic compounds and control their concentration in the finished wine. Mathematical models used to describe extraction and evolution phenomena in wine are also examined and the potential for future models to predict phenolic behaviour is discussed. Key Findings and Conclusions The impact of various winemaking techniques aimed at improving the extraction of phenolic compounds during red winemaking, as well as the subsequent reactions that take place following extraction, are qualitatively well understood. Mathematically, many of these techniques can be described in terms of their changing process variables such as temperature, solvent conditions and sold-liquid contact. Despite this, non-steady state models for mass transport or reaction kinetics of phenolic compounds in wine fermentation are currently unavailable in published literature. Further research into the production of global models capable of accurately describing this behaviour would be a significant advancement for industry and would aid in the development of adaptive process control technologies for red wine phenolic composition.