| Popis: |
The paper presents a new method for the reduction of waste production during juice processing through the reformulation of cloudy juices by ultrafiltration (UF), resulting in simultaneous production of a new type of cloudy juice of reduced sugar content. In contrast to the traditional juice production process, the final product was UF retentate. During UF, sugars were partially removed, while fibre and other macromolecular components present in a cloudy fraction, with health-promoting properties, were retained. Such treatment gives the possibility to reduce waste production during juice processing, because in the traditional approach, the cloudy fraction is usually treated as a waste after the clarification step. After UF in apple cloudy juice, the total content of soluble solids and sugars decreased from the initial values 11.0% and 10.4% to 9.2% and 8.8%, respectively; while in apple-beetroot cloudy juice, it reduced from 11.4% and 8.2% to 8.7% and 5.8%, respectively. At the same time, the cloudy fraction was retained and concentrated. The retention of soluble solids and sugars after the UF of apple juice was 66% and 67%, respectively, that is, 34% of soluble solids and 33% of the sugars were removed to the permeate. In apple-beetroot juice, 68% and 71% of soluble solids and sugars was retained, respectively. |
