title: Assessing the effects of different pectins addition on color quality and antioxidant properties of blackberry jam.
abstract: BACKGROUND
  In the last years pectin and other hydrocolloids were tested for improving the color stability and the retention of bioactive compounds in gelled fruit-based products. In line with these concerns, our study has been directed to quantify the changes in antioxidant status and color indices of blackberry jam obtained with different types of pectin (degree of esterification: DE, degree of amidation: DA) and doses in response to processing and storage for 1, 3 and 6 months at 20°C.
  
  
  RESULTS
  Blackberry jam was obtained by a traditional procedure used in households or small-scale systems with different commercial pectins (HMP: high-methoxyl pectin, LMP: low-methoxyl pectin and LMAP: low-methoxyl amidated pectin) added to three concentrations (0.3, 0.7 and 1.0%) and investigated in terms of total monomeric anthocyanins (TMA), antioxidant capacity expressed as ferric reducing antioxidant power (FRAP), total phenolics (TP), color density (CD) and percent of polymeric color, PC (%). Thermal processing resulted in significant depreciation of analyzed parameters reported to the corresponding values of fresh fruit as follows: TMA (69-82%), TP (33-55%) and FRAP (18-52%). Biologically active compounds and color were best retained one day post-processing in jams with LMAP followed by samples with LMP and HMP. Storage for 6 months brings along additional dramatic losses reported to the values recorded one day post-processing as follows: TMA (31-56%), TP (29-51%) and FRAP (20-41%). Also, both processing and storage resulted in significant increases in PC (%). The pectin type and dosage are very influential factors for limiting the alterations occurring in response to processing and storage. The best color retention and the highest TMA, TP and FRAP were achieved by LMAP, followed by LMP and HMP. Additionally, a high level of bioactive compounds in jam could be related to a high dose of pectin. LMAP to a level of 1% is the most indicated to provide the highest antioxidant properties in jam.
  
  
  CONCLUSIONS
  The retention of bioactive compounds and jam color stability were strongly dependent on the pectin type and dosage. By a proper selection of pectin type and dose could be limited the losses recorded in response to processing and storage.
authors.affiliation: Banat's University of Agricultural Sciences and Veterinary Medicine from Timisoara, Faculty of Food Processing Technology, Calea Aradului 119, 300645, Timisoara, Romania.
authors.forename: Mariana-Atena
authors.initials: MA
authors.lastname: Poiana
authors.affiliation: "Vasile Goldis" Western University of Arad, The Faculty of General Medicine, Pharmacy and Dental Medicine, Feleacului Street 1, 310396, Arad, Romania.
authors.forename: Melania-Florina
authors.initials: MF
authors.lastname: Munteanu
authors.affiliation: Banat's University of Agricultural Sciences and Veterinary Medicine from Timisoara, Faculty of Food Processing Technology, Calea Aradului 119, 300645, Timisoara, Romania.
authors.forename: Despina-Maria
authors.initials: DM
authors.lastname: Bordean
authors.affiliation: "Vasile Goldis" Western University of Arad, The Faculty of General Medicine, Pharmacy and Dental Medicine, Feleacului Street 1, 310396, Arad, Romania.
authors.forename: Ramona
authors.initials: R
authors.lastname: Gligor
authors.affiliation: Banat's University of Agricultural Sciences and Veterinary Medicine from Timisoara, Faculty of Food Processing Technology, Calea Aradului 119, 300645, Timisoara, Romania.
authors.forename: Ersilia
authors.initials: E
authors.lastname: Alexa
keywords: Blackberry jams; FRAP; Monomeric anthocyanins; Pectin; Polymeric color; Total phenolics