CHANGES IN LIMONIN AND NARINGIN LEVELS IN GRAPEFRUIT ALBEDO WITH MATURITY AND THE EFFECTS OF GIBBERELLIC-ACID ON THESE CHANGES

Variability in the two major bitter components, naringin and limonin, in grapefruit peel albedo was determined over four seasons in Marsh grapefruit. The effects of the growth regulator gibberellic acid (GA) on seasonal content of these two bitter components in albedo was also determined. Limonin and naringin content decreased with maturity and were affected by some treatments with (GA). In Marsh grapefruit albedo, naringin was the major flavanone glycoside, representing more than 80% of the total flavanones. In a non-bitter grapefruit hybrid, only traces of naringin were present in the albedo, and the non-bitter isomer naringenin 7-beta-rutinoside was the major flavonoid present.