Influence of fermentation conditions on production of plum (Prunus domestica L.) wine: A response surface methodology approach

Plum (Prunus domestica L.) is the most important and most commonly grown fruit species in Serbia, one of the leading plum-producing countries. It is mainly used for table consumption, drying and fruit brandy production. The use of plums for wine production is not sufficiently investigated. The aim of this study was to investigate the influence of temperature, pH and duration of fermentation on the plum wine composition and quality, and to optimize these factors by response surface methodology (RSM). Second order polynomial equations, which represent fitted models for investigated responses, are shown as adequate (R > 0.90 and P < 0.05). The average values of ethanol and glycerol content in plum wine were 6% and 5 g/L, respectively, while high methanol concentrations (above 1000 mg/L) were recorded in all wine samples. This requires further investigation of possible procedures to reduce the methanol content in the wines, according to its toxic properties to human. The optimal conditions for plum wine production, obtained by the application of RSM, were 18.3 °C, pH 3.0 and 7 days fermentation time. Apart from the problem of very high methanol concentrations, the plum wine produced with the optimal conditions had good sensory properties and acceptability.