Must concentrate using membrane technology

Concentrated must is a natural sweetener in wine production, and in addition, it is a vitamin- and aroma-rich drink. In this study the basis of a complex membrane process was developed for must concentration. Modeling the experimental results and using recent economic data, the optimal process parameters were calculated to produce 45° Brix sugar concentration in the retentate, which saves the must without preservatives. The costs of the membrane process were compared with those of traditional evaporation.

The modeling, optimization and economical investigations show that the highest necessary sugar concentration, which saves the must without preservatives — about 45 °Brix (450 g/l) — can be reached by a combined RO–NF system with the following operation parameters: C for the RO membrane: 60 bar transmembrane pressure at 20°C temperature C for the NF membrane: 70 bar transmembrane pressure at 40°C temperature C for both cases: a high recycle flow rate. According to the cost estimations, the complex membrane technology is a much cheaper procedure than evaporation.