STABILIZATION OF CARROT JUICE BY DILUTE ACID TREATMENT

SUMMARY– A problem arises if juice extracted from raw carrots is heated to about 180° before or during conventional canning practices. An unsightly, unappetizing coagulum forms and the color of the juice precipitates with the coagulum. The coagulum is not as evident if the carrots are heated 5 min in water prior to juice extraction, but the juice loses some of its bright-orange color. The canned juice extracted from carrots heated 5 min in a .05 N acetic acid solution does not coagulate and the amount of juice which can be extracted from the carrots is 3.3% greater than that from carrots heated 5 min in water. The centrifuged juice from acid-treated carrots had a brighter orange color than juice from the water-treated carrots. The color notation was Rd, 23.7, a, 30.4 and b, 34.8 for juice from acid-treated carrots compared with a notation of Rd, 19.2, a, 24.4 and b, 31.4 for the juice from water-treated carrots. The canned juice extracted from raw carrots had less pectic substances and starch and about the same amount of protein as the canned juice from the carrots heated in water or .05 N acetic acid, but the canned juice from raw carrots coagulated. The juice from carrots heated in acid does not form a coagulum and maintains its orange color, probably because of the action of the heat and acid on the protoplasmic liquid of the cell before or immediately after the cell is ruptured.