title: Processing black mulberry into jam: effects on antioxidant potential and in vitro bioaccessibility.
abstract: BACKGROUND
  Black mulberries (Morus nigra) were processed into jam on an industrialised scale, including the major steps of: selection of frozen black mulberries, adding glucose-fructose syrup and water, cooking, adding citric acid and apple pectin, removing seeds, and pasteurisation. Qualitative and quantitative determinations of antioxidants in black mulberry samples were performed using spectrophotometric methods, as well as HPLC- and LC-QTOF-MS-based measurements. These analyses included the determination of total polyphenolic content, % polymeric colour, total and individual anthocyanin contents, antioxidant capacity, and in vitro bioaccessibility in processing samples.
  
  
  RESULTS
  Jam processing led to a significant reduction in total phenolics (88%), total flavonoids (89%), anthocyanins (97%), and antioxidant capacity (88-93%) (P < 0.05). Individual anthocyanin contents, determined using HPLC analysis, also showed a significant decrease (∼99% loss). In contrast, % recovery of bioaccessible total phenolics, anthocyanins, and antioxidant capacity (ABTS assay) increased after jam processing (16%, 12%, and 37%, respectively).
  
  
  CONCLUSIONS
  Fruit processing resulted in losses of polyphenols, anthocyanins, and antioxidant capacity of black mulberry jam. Optimisation of food processing could help to protect the phenolic compounds in fruits which might be helpful for the food industry to minimise the antioxidant loss and improve the final product quality. © 2016 Society of Chemical Industry.
authors.affiliation: Faculty of Engineering and Natural Sciences, Food Engineering Department, Istanbul Sabahattin Zaim University, Halkalı, Istanbul, Turkey.
authors.forename: Merve
authors.initials: M
authors.lastname: Tomas
authors.affiliation: Faculty of Engineering, Food Engineering Department, Okan University, Akfirat-Tuzla, Istanbul, Turkey.
authors.forename: Gamze
authors.initials: G
authors.lastname: Toydemir
authors.affiliation: Faculty of Chemical and Metallurgical Engineering, Food Engineering Department, Istanbul Technical University, Maslak, Istanbul, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Boyacioglu
authors.affiliation: Wageningen University & Research, Wageningen Plant Research, Bioscience, Wageningen, The Netherlands.|Wageningen University, Laboratory of Plant Physiology, Wageningen, The Netherlands.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Hall
authors.affiliation: Wageningen University & Research, Wageningen Plant Research, Bioscience, Wageningen, The Netherlands.
authors.forename: Jules
authors.initials: J
authors.lastname: Beekwilder
authors.affiliation: Faculty of Chemical and Metallurgical Engineering, Food Engineering Department, Istanbul Technical University, Maslak, Istanbul, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Capanoglu
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D000975:Antioxidants / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D031625:Morus / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D059808:Polyphenols / Q000032:analysis
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols
keywords: antioxidant; black mulberry jam; in vitro bioaccessibility; phenolics