OCCURRENCE OF 1,2,3,4-TETRAHYDRO-BETA-CARBOLINE-3-CARBOXYLIC ACID ANDHYL-1,2,3,4-TETRAHYDRO-BETA-CARBOLINE-3-CARBOXYLIC ACID IN FRUIT JUICES, PUREES, AND JAMS

1,2,3,4-Tetahydro-beta-carboline-3-carboxylic acid (THCA) and hyl-1,2, 3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCA) as two diastere oisomers (1S,3S and 1R,3S), occur in fruit juices, juices and fruit pu rees for infants, and jams. Concentrations in commercially prepared fr uit juices were in the ranges 0.01-1.45, 0.02-9.1, and 0.01-2.48 mu g/ g for THCA, 1S,3S-MTCA, and 1R,3S-MTCA, respectively. The content was higher in citrus juices (orange, grapefruit) than in other juices (gra pe, apple, pineapple, peach, banana, pear, tomato). Commercially prepa red infant juices contained 0.14, 0.52, and 0.16 mu g/g on average, fo r THCA, 1S,3S-MTCA, and 1R,3S-MTCA, respectively. Commercial infant fr uit purees averaged 0.04, 0.35, and 0.11 mu g/g for THCA, 1S,3S-MTCA, and 1R,3S-MTCA. Jams and marmalades averaged 0.23, 0.76, and 0.25 mu g /g for THCA, 1S,3S-MTCA, and 1R,3S-MTCA, respectively. The reported en dogenous presence of these substances in humans could be influenced by their exogenous ingestion in the diet. This is the first specific rep ort on THCA and MTCA in fruit products.