title: Carotenoid stability in fruits, vegetables and working standards - effect of storage temperature and time.
abstract: The effects of freezing and storage temperature on the mass fraction of α- and β-carotene, β-cryptoxanthin, lutein, lycopene and zeaxanthin in minimally processed fresh food products, were evaluated after sample preparation, extraction and saponification (only when strictly necessary). Effects of freezing and long-term stability were studied at two temperatures, -20 and -70°C, using high performance liquid chromatography (reversed phase columns, UV-Vis diode array detector) at time points during storage; measurement uncertainty was included in the evaluation. Stability of working standard solutions was also examined. Freezing did not affect the carotenoid mass fraction under the conditions studied. Carotenoids in orange, cherry, peach, apple, and kale were stable (except α-carotene and zeaxanthin in peach) for 13, 9.7, 5.7, 2.5 and 7.5months, respectively. For these food sample matrices, no significant difference between the freezing/storage at -20 and -70°C was observed. Standard solutions (0.05-5μg/mL) were stable for at least 6months at -70°C, except lycopene which at 0.05μg/mL was apparently stable only for six weeks.
authors.affiliation: Departamento de Alimentação e Nutrição, Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA, I.P.), Av. Padre Cruz, 1649-016 Lisboa, Portugal. Electronic address: m.graca.dias@insa.min-saude.pt.
authors.forename: M Graça
authors.initials: MG
authors.lastname: Dias
authors.affiliation: CCMM/DQB - Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: M Filomena G F C
authors.initials: MF
authors.lastname: Camões
authors.affiliation: Departamento de Alimentação e Nutrição, Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA, I.P.), Av. Padre Cruz, 1649-016 Lisboa, Portugal.
authors.forename: Luísa
authors.initials: L
authors.lastname: Oliveira
mesh_terms: D001937:Brassica / Q000737:chemistry; D002338:Carotenoids / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D061353:Food Storage / Q000295:instrumentation / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D027861:Prunus / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014675:Vegetables / Q000737:chemistry*
chemical_list: D002338:Carotenoids
keywords: Carotenoids; Freezing temperature; HPLC; Stability; Storage time and temperature