title: Development of delayed bitterness and effect of harvest date in stored juice from two complex citrus hybrids.
abstract: BACKGROUND
  Mandarins and mandarin hybrids have excellent flavor and color attributes, making them good candidates for consumption as fresh fruit. When processed into juice, however, they are less palatable, as they develop delayed bitterness when stored for a period of time. In this study the kinetics of delayed bitterness in two citrus mandarin hybrid siblings, 'Ambersweet' and USDA 1-105-106, was explored by sensory and instrumental analyses. In addition to the bitter limonoids, other quality factors (i.e. sugars, acids, pH, soluble solids content (SSC), titratable acidity (TA) and the ratio SSC/TA) were also measured.
  
  
  RESULTS
  The two citrus hybrid siblings had different chemical profiles, which were perceived by taste panels. USDA 1-105-106 developed delayed bitterness when the juice was stored for more than 4 h, similar to juice from 'Navel' oranges, but 'Ambersweet' did not. Bitterness in 'Ambersweet' was more affected by harvest maturity, as juice from earlier harvest had lower SSC but higher TA and bitter limonoids.
  
  
  CONCLUSIONS
  Since juice of USDA 1-105-106 shows delayed bitterness when stored for more than 4 h, this cultivar is not suitable for juice processing. Our finding that siblings can differ in chemical and sensory properties emphasize the importance of post-processing storage studies before releasing cultivars for juice.
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Smita
authors.initials: S
authors.lastname: Raithore
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Sharon
authors.initials: S
authors.lastname: Dea
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Greg
authors.initials: G
authors.lastname: McCollum
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Manthey
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Jinhe
authors.initials: J
authors.lastname: Bai
authors.affiliation: École Nationale Supérieure Agronomique de Toulouse, Toulouse, France.
authors.forename: Clotilde
authors.initials: C
authors.lastname: Leclair
authors.affiliation: Citrus Research and Education Center, University of Florida, Lake Alfred, FL, USA.
authors.forename: Faraj
authors.initials: F
authors.lastname: Hijaz
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Narciso
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Baldwin
authors.affiliation: US Horticultural Research Laboratory, Agricultural Research Service, USDA, Fort Pierce, FL, 34945, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Plotto
mesh_terms: D001584:Benzoxepins; D002957:Citrus / Q000737:chemistry / Q000235:genetics*; D061353:Food Storage; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D036701:Limonins; D013649:Taste; D013997:Time Factors
chemical_list: D001584:Benzoxepins; D036701:Limonins; C059405:nomilin; C001546:limonin
keywords: limonin; mandarin; nomilin; orange juice; sensory; tangerine; ‘Ambersweet’