Evaluation of bitter melon (Momordica charantia) cultivars grown in Texas and levels of various phytonutrients.

Abstract

In the USA, Momordica charantia is relatively unknown and is usually found in specialty markets. In the present study, cultivation of five bitter melon cultivars grown under field conditions in College Station (TX, USA), was evaluated. Additionally, ascorbic acid, amino acids and phenolic compounds were quantified from various cultivars grown in different years. The yield of the first year of evaluation was comparable to other bitter melon growing regions, ranging from 9371.5kg ha-1 for the Japanese Spindle cultivar to 20 839.1kg ha-1 for the Hong Kong Green cultivar. Multivariate analysis suggests a strong correlation between yield and growth degree days, water use efficiency and organic matter, as well as an inverse correlation with the amount or precipitation during the growing season. The highest levels of total ascorbic acid were shown in the Japanese Spindle cultivar (162.97 mg 100 g-1 fresh fruit), whereas the lowest levels were expressed in the Hong Kong Green cultivar (42.69 mg 100 g-1 fresh fruit). The highest levels of total phenolics were consistently found the Indian White cultivar, in the range 10.6-12.5mg g-1 catechin equivalents. Seven phenolics and organic acids were identified and quantified by liquid chromatography-mass spectrometry and high-performance liquid chromatography, respectively. Additionally, the highest levels of total amino acids were found in the Large Top cultivar. The current 3-year field study demonstrates that it is feasible to grow bitter melon commercially in Texas with proper climatic and agronomic conditions. Bitter melon is a rich source for ascorbic acid, amino acids and phenolic compounds, which makes it a valuable food source with respect to improving human health. © 2018 Society of Chemical Industry.