Abstract: An apparatus for concentrating a vegetable and/or fruit product has a concentration unit having a plurality of tubular membrane modules connected in series, a single-axis eccentric screw pump connected to its inlet for supplying the product and another single-axis eccentric screw pump connected to its outlet for discharging the product concentrated by reverse osmosis by the concentration unit. The product is supplied under a high-pressure condition such that the pressure at the inlet is within a specified range, and the apparatus is operated such that the pressure at the outlet is also within another specified range and the pressure difference between the inlet and the outlet be greater than a certain minimum pressure value.

Abstract: A concentrated vegetable and/or fruit product is obtained by reverse osmosis by a method of first preparing a vegetable and/or fruit product including seeds, epidermis and/or sarcocarp as a solid component, causing it to flow down under a pressured condition to a concentration unit having an inlet, an outlet and tubular membrane modules connected in series such that it is supplied to the tubular membrane modules through a single-axis eccentric screw pump attached to the inlet and discharging a concentrated product from the tubular membrane modules through another single-axis eccentric screw pump which is attached to the outlet.

Abstract: Nitrate nitrogen is removed from a vegetable juice by first concentrating the vegetable juice to Brix concentration 10-60%, or preferably 20-40%, to obtain a concentrate and subjecting this concentrate to electrodialysis.

Abstract: An apparatus for concentrating a vegetable and/or fruit product has a concentration unit having a plurality of tubular membrane modules connected in series, a single-axis eccentric screw pump connected to its inlet for supplying the product and another single-axis eccentric screw pump connected to its outlet for discharging the product concentrated by reverse osmosis by the concentration unit. The product is supplied under a high-pressure condition such that the pressure at the inlet is within a specified range, and the apparatus is operated such that the pressure at the outlet is also within another specified range and the pressure difference between the inlet and the outlet be greater than a certain minimum pressure value. By a method of this invention, concentrated vegetable and/or fruit products with solid components approximately in their original forms can be obtained.