Identification of the potential inhibitors of malolactic fermentation in wines
Malolactic fermentation plays an important role in reducing acidity and improving both the microbiological stability and the aroma profile of wines. The conditions required for the induction and appropriate course of MLF include initial temperatures of 20 °C to 25 °C, a free-SD2 content below 10 mg L -1, a total SD2 concentration below 30 mg L-1, a pH level between the range of 3.2 and 3.4, and nutrients, which are obtained from the sediment of yeast cells (Lasik, 2013). Spontaneous MLF, however, cannot be guaranteed due to the harsh environmental conditions present in wine. Malolactic fermentation may fail or occur many months after alcoholic fermentation is complete, which impairs the production processes and may cause wine-depreciation associated with the occurrence of spoilage or the production of toxic compounds (Oorizzo et al., 2016).