Abstract

The variability of amino acid levels including gamma-aminobutyric acid (GABA) was investigated in six cultivars of bitter melon (Momordica charantia L.) of different origins: Nikko and Peacock from Japan, Galaxy and Verde Buenas from Philippines and two native cultivars from China and Korea. Cultivars varied considerably in the amounts of different amino acids. Among them, the cultivar Verde Buenas recorded the highest amounts of seven different amino acids with the content of other amino acids at a satisfactory level. The cultivar Galaxy contained the highest amount of GABA. Second only to Verde Buenas, the Korean native performed the best, having significantly high levels of five different amino acids followed by the China native exhibiting the highest amounts of alanine, phenylalanine and proline. Although the cultivar Nikko contained the highest amount of arginine, it recorded the lowest values for most of the amino acids. The cultivars Nikko, Peacock and Galaxy did not contain methionine amino acids. These results demonstrated that bitter melon cultivars varied in the amount of different amino acids and GABA and hence have a high potential as a good source of amino acids and GABA in the development of food supplements.

Key words: Amino acid, cultivar, gamma-aminobutyric acid, GABA, Momordica charantia L.