title: Effects of condensed tannins on anthocyanins and colour of authentic pomegranate (Punica granatum L.) juices.
abstract: This study was conducted to determine the effects of condensed tannins (CT) on anthocyanins (ACNs) and colour of pomegranate juice (PJ) samples obtained from nine registered varieties in Turkey. CT-catechins (CTCs) reactive to vanillin and phloroglucinol adducts of CT contents were determined. CTC and ACN contents of PJs highly depended on variety (p<0.01), and ranged from 31 to 155 mg/L juice and from 47 to 405 mg/L juice, respectively. As catechin-phloroglucinol content increased, ACN content also increased (r=0.866). Strong logarithmic correlation between the ratio of ACN contents to catechin-phloroglucinol contents and polymeric colour (PC) values of the samples was found (r=-0.822). When PC value of PJs was ⩾8% or ratio of ACN contents to catechin-phloroglucinol contents of PJs was ⩽2.82, ACN contents of the samples determined by spectrophotometric method were higher than those determined by HPLC.
authors.affiliation: Institute of Food Safety, Ankara University, Diskapi Campus, Diskapi, 06110 Ankara, Turkey. Electronic address: mturkyilmaz@ankara.edu.tr.
authors.forename: Meltem
authors.initials: M
authors.lastname: Türkyılmaz
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Ankara University, Diskapi, Ankara 06110, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozkan
mesh_terms: D000872:Anthocyanins / Q000032:analysis*; D001628:Beverages / Q000032:analysis*; D002392:Catechin / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D003116:Color; D005638:Fruit / Q000737:chemistry*; D029561:Lythraceae / Q000737:chemistry*; D044945:Proanthocyanidins / Q000032:analysis*; D014421:Turkey
chemical_list: D000872:Anthocyanins; D044945:Proanthocyanidins; D002392:Catechin
keywords: Anthocyanin; Condensed tannin; Polymeric colour; Pomegranate juice