Production of tea vinegar by batch and semicontinuous fermentation.

The fermented tea vinegar combines the beneficial properties of tea and vinegar. The complete fermentation takes 4 to 5 weeks in a batch culture and thus can be shortened by semi continuous/ continuous fermentation using immobilized bacterial cells. In the present study, alcoholic fermentation of 1.0 and 1.5% tea infusions using Saccharomyces cerevisae G was carried out that resulted in 84.3 and 84.8% fermentation efficiency (FE) respectively. The batch vinegar fermentation of these wines with Acetobacter aceti NRRL 746 at the initial 1% acidity yielded 4.5 and 4.7% volatile acidity with 71.4 and 73% FE in 24 days. The semi continuous fermentation using sugarcane bagasse adsorbeded A.aceti cells produced 4.4% of volatile acidity from 1.5% tea wine (8.9% ethanol and 1.0% acidity), in 9 flow cycles, each of 4 h duration in a fermentation column at 50 ml/h. In the scale up process, 600 ml 1.5% tea wine produced 4.3% volatile acidity at 42.7% FE in 9 flow cycles of 12 h duration each.