Commercially available carrots were peeled and washed with water. They were crushed into small pieces (of average size less than 2.0 mm) by a crusher while they were sprayed with an aqueous solution of citric acid (with citric acid content of 10.0 weight %) such that citric acid would be 0.15 weight % of the crushed carrots. Next, the crushed carrots thus obtained were supplied to a contherm (Model KV-12 produced by Iwai Kikai Kogyo-sha) and heated to 85° C. for inactivation of enzymes. They were then squeezed by a counter-rotation twin-screw extruder to collect juice and the juice was cooled. The slit in the barrel of the extruder was 0.5 mm in width and the screws were rotated at the rate of 10 rpm. In the extruder, the screws were arranged according to the Screw Pattern A given below:
Screw Pattern A: (Inlet side) - parallel screw with length 150 mm and groove depth of 15 mm - parallel screw with length 100 mm and groove depth 10 mm tapered collar - parallel screw with length 60 mm and groove depth 6 mm - tapered screw with length 50 mm and groove depth 5 mm - tapered screw with length 40 mm and groove depth 4 mm - tapered collar - (outlet side).