| dc.description.abstract | Cucumis melo L. is one of the most commercial and economical crops in the world with several health beneficial compounds as such carotenoids, amino acids, vitamins A and C, minerals and dietary fiber. In the first study, we aimed to characterize volatile organic compounds (VOCs) in 28 melon breeding lines (BL) providing useful information for improving fruit flavor and aroma. The VOCs were identified and characterized using head space solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and 113 VOCs, including 15 esters, 27 aldehydes, 35 alcohols, 14 ketones, 4 acids, 10 hydrocarbons, 5 sulfurs, and 3 other compounds were identified. The highest average contents of all the VOCs were found in BL-30 (13973.07 µg/kg FW) and the lowest was in BL-22 (3947.13 µg/kg FW). The highest number of VOCs was present in BL-20 (77) and the lowest in BL-22 (42). BL-9 had high levels of carotenoid-derived VOCs. The compounds with the highest contents were benzaldehyde, geranylacetone, and β-ionone. Quality parameters such as color and sugar contents of melons were also measured. All the melon color readings were within the typically acceptable limits due to the presence of carotenoids and β-carotene. BL-22 and BL-14 had the highest (55.54 mg/g FW) and lowest (19.17 mg/g FW) sugar contents, respectively. Principal component analysis (PCA) produced diverse clusters of breeding lines and different chemical classes that contributed to flavor and aroma. BL-4, BL-7, BL-12, BL-20, and BL-30 were selected as important breeding lines based on their organoleptic, antimicrobial and health-beneficial properties. This work thus provides useful information for breeding to improve melon flavor and aroma properties according to consumer preferences, and to improve the flavor, aroma and antimicrobial properties for food safety.
In the second study, we aimed to identify the VOCs along with phytonutrient profiles such as sugars and pH as well as carotenoid contents and antioxidant activities in the melon BL grown in 2018 and 2019 at Uvalde, Texas. We identified 72 VOCs from 2018 lines and 109 VOCs from 2019 breeding lines. The radical scavenging activities were determined using the total phenolic contents (TPC), 2,2-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays, carotenoid and sugars were analyzed using high-performance liquid chromatography (HPLC). PCA was used to correlate the breeding lines with VOCs. Major VOCs identified in the breeding lines from both the years were geranylacetone, benzyl alcohol, D-limonene, β-ionone, benzaldehyde, (E)-2-nonenal and citral. BL-96, BL-136 and BL-53 were the most prominent breeding lines observed from 2018, based on the quality parameters such as pH, sugar, and citric acid levels as well as their antioxidant activities, antimicrobial properties and carotenoid concentrations. From the year 2019, the lowest pH (5.82) was observed in BL 3-43-1 along with the highest total sugar content, making it noteworthy. Along with BL 3-43-1, the lines 3-31-1, 2-44-1, 2-42-1 and 3-22 can be considered for future breeding programs based on their organoleptic profiles, high radical scavenging activities and high carotenoid concentrations. | en |
