| dc.description.abstract | In the United States, bitter melon (Momordica charantia L.), is an underutilized horticultural crop that has been traditionally used to manage diabetes and various inflammatory conditions. In this study, cultivation of five bitter melon cultivars grown under field conditions in College Station, Texas, was evaluated. Fruit quality was measured by the levels of phytochemicals such as vitamin C, amino acids and total phenolics. The yield for the various cultivars was comparable to other bitter melon growing regions. The highest levels of total ascorbic acid were shown in the Japanese Spindle, while the lowest levels were expressed in the Hong Kong Green. The levels of total phenolics and amino acids were also evaluated. Ultrahigh performance liquid chromatography-high resolution mass spectrometry was used to identify 15 phenolic and 46 triterpenoids in various bitter melon extracts. Total phenolic levels were highest in methanolic extracts of the inner tissue of the Indian Green cultivar, which also correlated to the highest DPPH radical scavenging activity. Differential inhibition of α-amylase and α-glucosidase activity was observed in response to extract polarity, cultivar and tissue type. Furthermore, we evaluated the postharvest changes of three household processing techniques on the levels of vitamin C, amino acids, total phenolics, and antioxidant activity of bitter melon during storage at various temperatures for up to 8 weeks. The largest decrease of vitamin C was observed in blended bitter melon samples stored at 10 °C for one week, while the highest levels of vitamin C were observed in chopped fruit stored at 2 °C and -20 °C. Total phenolics and DPPH activity drastically increased in chopped fruit stored at -20 °C while this was not the case in whole fruit.
During maturation, lutein and β- carotene levels fluctuated depending on the tissue type and the levels of trans-lycopene were found to be high in aril tissues. Additionally, various carotenoid esters and cislycopene isomers have also been identified in bitter melon for the first time. Lastly, bitter melon extracts and compounds were found to influence on the expression of genes involved in the formation of the NLRP3 inflammasome complex in RAW 264.7 macrophage cells. | en |
