title: A comparative study on composition and antioxidant activities of supercritical carbon dioxide, hexane and ethanol extracts from blackberry (Rubus fruticosus) growing in Poland.
abstract: BACKGROUND
  Large quantities of blackberry seeds are produced as a pomace during the processing of juice and jam production; this by-product is a very interesting raw material both for oil manufacturing and as a source of bioactive compounds. In this work the composition, yield and antioxidant activity of three types of Rubus fructicosus pomace extracts isolated by liquid extraction using solvents of different polarity, as well with supercritical CO2fluid extraction have been compared.
  
  
  RESULTS
  The highest extract yield was reported for Soxhlet extraction using ethanol as a solvent (14.2%). Supercritical carbon dioxide and hexane extracts were characterised by the highest content of phytosterols (1445 and 1583 mg 100 g-1of extract, respectively) among which β-sitosterol was the main one, while the concentration of tocopherols, with predominant γ-isomer, was the highest for both hexane and ethanol extracts, being 2364 and 2334 mg 100 g-1, respectively. Using a GC-MS method 95 volatiles, in which non-saturated aldehydes were predominant, were identified in the essential oil of seed pomace and in the volatile oil isolated from supercritical extract. The ethanolic extract which is characterised by the highest phenolic content (9443 mg GAE 100 g-1) exhibited the highest antioxidant activity (according to the ABTS•+and DPPH•assays).
  
  
  CONCLUSIONS
  All pomace extracts examined were of high quality, rich in essential omega fatty acids and with a very high content of bioactive compounds, such as phytosterols and tocopherols. The high nutritional value of extracts from berry seed pomace could justify the commercialisation of specific extracts not only as food additives but also as cosmetic components. © 2017 Society of Chemical Industry.
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Wajs-Bonikowska
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Stobiecka
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Radosław
authors.initials: R
authors.lastname: Bonikowski
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Krajewska
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sikora
authors.affiliation: Institute of General Food Chemistry, Lodz University of Technology, Stefanowskiego, Lodz, Poland.
authors.forename: Józef
authors.initials: J
authors.lastname: Kula
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D002245:Carbon Dioxide / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011044:Poland; D065856:Rubus / Q000737:chemistry* / Q000254:growth & development
chemical_list: D000975:Antioxidants; D006586:Hexanes; D010936:Plant Extracts; D002245:Carbon Dioxide; D000431:Ethanol
keywords: Rubus fruticosus; antioxidant activity; blackberry; fatty acids; phytosterols; polyphenols; pomace; seeds; supercritical extracts; tocopherols; volatiles