Investigation of Osmotic Distillation Technique for Beer Dealcoholization

A growing demand for low-alcohol drinks, due to health and social benefits resulting from lower alcohol consumption, has given rise to the development of techniques for alcohol reduction or elimination in beverages. The main difficulty is the development of a low alcohol content product with sensory properties similar to the original one. This work presents a preliminary study on the production of alcohol free beer (alcohol content <= 0.5 %vol) by osmotic distillation technique, which allows to operate at low temperature and atmospheric pressure, using water as ethanol stripping agent. To this goal, a lab-scale plant equipped with a commercial membrane contactor with hollow fibers was set up. The effect of different stripping agents for ethanol removal on dealcoholization kinetics and on chemical and physical properties of the dealcoholized beer (i.e alcohol content, colour, pH, polyphenols, antioxidant activity) was investigated. Finally, the ethanol mass flux through the membrane during the dealcoholization process was measured and theoretically calculated with a good agreement.