Utilização de membranas cerâmicas no tratamento de vinhos tintos.

Abstract

In this research, the use of ceramic membranes in a process of microfiltration of red wine was studied. The MR1-20 membrane, made of a mixture of clay and alumina, presenting a cylindrical configuration with one channel, length of approximately 22-23 cm and pores size varying between 0,5 and 0,9 μm was used in a dead-end type of microfiltration system. The permeate flow as well as the quality of the filtered wine were investigated under different trans-membrane pressures (0,5, 1,0 e 1,5 bar). It was observed an increase in the flow with an increased pressure, and the greater increment was achieved with a pressure of 1,5 bar. All tests showed similar behavior and an exponential decrease in the permeate flow during the process was observed. A step for membrane characterization with experimental wine was carried out with the objective of identifying the best operational. The pressure of 0,5 bar presented the best operational outcomes, and therefore was selected for the development of further experiments. Following the determination of the best operational pressure (0,5 bar), 3 samples of commercial red wine were filtered and physic-chemical analyses as well as microbiological analyses were performed before and after the microfiltration process to determine the efficiency of ceramic membranes for treating red wine. Following that, the results were compared with the standards presented in the Brazilian legislation. The outcomes of this research have shown that the ceramic membrane MR1-20 was efficient to treat red wines, decreasing 97% of turbidity and reducing approximately 65% of mesophilic bacteria and yeast. Moreover, the color index was slightly reduced (6%). However, the difficulty of maintaining the operational flow as well as the non-sterilization of the wine was the identified factors that must be better understood and clarified in future studies.