title: Modulation of flavanone and furocoumarin levels in grapefruits (Citrus paradisi Macfad.) by production and storage conditions.
abstract: Grapefruits grown under organic or conventional systems were analyzed for 6,7-dihydroxybergamottin (DHB) and flavanones using HPLC, and DPPH activity and ORAC using a micro-plate reader. Grapefruits harvested in November 2008 (E-1) and February 2010 (E-2) were stored at room temperature (RT) and 9 °C for four weeks. Higher levels of DHB were observed in conventional grapefruits during the second (4.7 ± 0.2 μg/g), third (1.5 ± 0.2 μg/g) and fourth (2.5 ± 0.2 μg/g) week of storage at room temperature in E2. Among flavonoids analyzed, narirutin (666.7 ± 33.9 μg/g), neohesperidin (17.5 ± 1.3 μg/g), didymin (75.5 ± 5.6 μg/g) and poncirin (130.8 ± 10.4 μg/g) levels were significantly higher (P⩽0.05) in organic grapefruits over conventional grapefruits at harvest and storage in E-1. Although DPPH levels were moderately correlated with grapefruit flavanone content, variability in the individual flavanone activity was pronounced, resulting in non-significant differences in antioxidant activity between organic and conventional grapefruits.
authors.affiliation: Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA.
authors.forename: Kranthi K
authors.initials: KK
authors.lastname: Chebrolu
authors.affiliation: Texas A&M AgriLife Research Center, Weslaco, TX, USA. Electronic address: jljifon@ag.tamu.edu.
authors.forename: J
authors.initials: J
authors.lastname: Jifon
authors.affiliation: Vegetable and Fruit Improvement Center, Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA. Electronic address: b-patil@tamu.edu.
authors.forename: Bhimanagouda S
authors.initials: BS
authors.lastname: Patil
mesh_terms: D000383:Agriculture / Q000379:methods; D000975:Antioxidants / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D032083:Citrus paradisi / Q000737:chemistry* / Q000254:growth & development*; D004187:Disaccharides; D044950:Flavanones / Q000032:analysis*; D005419:Flavonoids / Q000032:analysis; D005519:Food Preservation / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D011564:Furocoumarins / Q000032:analysis*; D058871:Organic Agriculture / Q000379:methods
chemical_list: D000975:Antioxidants; D004187:Disaccharides; D044950:Flavanones; D005419:Flavonoids; D011564:Furocoumarins; C500601:narirutin; C028610:flavanone
keywords: Antioxidant activity; Dihydroxybergamottin; Flavanones; Grapefruit; Organic production