Fermentation processes by immobilized cell systems in beverage production

Abstract

Immobilized cell technology has been investigated and used in various bio-industries as well as in processes based on alcoholic fermentation, like beer, wine and cider fermentation processes. Some of the most important reasons that favour immobilized over suspended cell systems include faster fermentation rates, increased volumetric productivity, and possibility for continuous operation. In spite of the fact the immobilized yeast technology was paying continual attention in these industries over the last 30 years, today, this technology is well established in very limited number of cases such as secondary beer fermentation and alcoholfree and low-alcohol beer production as well as sparkling wine production. However, in some more complex processes with various side reactions that effect flavour formation and final product quality, like primary beer fermentation, wine and cider fermentation, immobilized cell technology is still under scrutiny on the lab or pilot levels. Immobilized cell phisiology control and fine-tuning of the flavour compounds formation during the long term fermentation processes remain the major challenges for successful application of immobilized cell technology on an industrial scale. This paper describes and discusses the key factors for the implementation of this technology on an industrial level, like carrier materials, immobilization technology and bioreactor design.