In the paper the structure and properties of montmorrilonite, the major component of bentonite are presented. Due to its properties, bentonite is applied in fermentation and fruit-vegetable industry as clarification substance to wine drinks and fruit juices. Bentonit is basically used to remove the opacities of high-molecular proteins present in the wine and juice. The particles of protein are easily adsorbed between the clay flakes of bentonites, especially Na-bentonites, which possess very good