Fermentation of Apple Juice in a PDMS Membrane Bioreactor

摘要

A novel technology for fermentation of apple juice with a PDMS membrane bioreactor was developed in the study. The membrane bioreactor including a fermentor with effective volume 5L and a flat pervaporation module with 0.08 m 2 PDMS membrane was constructed for fermentation of fresh apple juice and recovery of ethanol and other aroma compounds from the broth. The microbial concentration in the broth reached a high magnitude of 10 8 , so that the saccharide was converted to ethanol in a higher rate than a conventional fermentation process. Through two-stage condensation of the permeate vapor, the condensate with high ethanol content was collected and used for making apple brandy according to GC analysis of its main aroma compounds. The retentate retained in upstream side of the membrane containing natural organic acids and other nutrients could accordingly be processed as acidic fermented beverage with a low alcoholic content. The experimental results showed the potential application in producing higher value product by fermentation of apple juice with the PDMS membrane bioreactor.