title: Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam.
abstract: The organic acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by HPLC. The sample preparation was simple, involving only extraction with methanol (40 degrees C) and filtration through a Sep-pack C18 cartridge. The chromatographic separation was achieved using an ion exclusion column, Nucleogel Ion 300 OA (300 x 7.7 mm), in conjunction with a column heating device at 30 degrees C. An isocratic elution with H(2)SO(4) 0.01 N as the mobile phase, with a flow rate of 0.1 mL/min, and UV detection at 214 nm were used. These analyses showed that all samples presented a similar profile composed of at least six identified organic acids: citric, ascorbic, malic, quinic, shikimic, and fumaric acids. Several samples also contained oxalic acid. This study suggests that the organic acids levels and ratios may be useful for the determination of percent fruit content of quince jams. The citric acid value can also be used in the differentiation of the type of manufacture of the commercial quince jams (homemade or industrially manufactured).
authors.affiliation: CEQUP/Serviço de Farmacognosia, Faculdade de Farmácia, Universidade do Porto, R. Aníbal Cunha, 164, 4050-047 Porto, Portugal.
authors.forename: Branca M
authors.initials: BM
authors.lastname: Silva
authors.forename: Paula B
authors.initials: PB
authors.lastname: Andrade
authors.forename: Gisela C
authors.initials: GC
authors.lastname: Mendes
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Seabra
authors.forename: Margarida A
authors.initials: MA
authors.lastname: Ferreira
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis; D002264:Carboxylic Acids / Q000032:analysis*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D019343:Citric Acid / Q000032:analysis; D005511:Food Handling; D005638:Fruit / Q000737:chemistry*; D005650:Fumarates / Q000032:analysis; D008293:Malates / Q000032:analysis; D000432:Methanol; D019815:Oxalic Acid / Q000032:analysis; D011801:Quinic Acid / Q000032:analysis; D027824:Rosaceae / Q000737:chemistry*; D012765:Shikimic Acid / Q000032:analysis
chemical_list: D002264:Carboxylic Acids; D005650:Fumarates; D008293:Malates; D011801:Quinic Acid; D019343:Citric Acid; D012765:Shikimic Acid; C030298:malic acid; C032005:fumaric acid; D019815:Oxalic Acid; D001205:Ascorbic Acid; D000432:Methanol