title: Characterization of polysaccharides extracted from spent coffee grounds by alkali pretreatment.
abstract: Spent coffee grounds (SCG), obtained during the processing of coffee powder with hot water to make soluble coffee, are the main coffee industry residues and retain approximately seventy percent of the polysaccharides present in the roasted coffee beans. The purpose of this study was to extract polysaccharides from SCG by using an alkali pretreatment with sodium hydroxide at 25°C, and determine the chemical composition, as well as the antioxidant and antimicrobial properties of the extracted polysaccharides. Galactose (60.27%mol) was the dominant sugar in the recovered polysaccharides, followed by arabinose (19.93%mol), glucose (15.37%mol) and mannose (4.43%mol). SCG polysaccharides were thermostable, and presented a typical carbohydrate pattern. Additionally, they showed good antioxidant activity through different methods and presented high antimicrobial percent inhibition against Phoma violacea and Cladosporium cladosporioides (41.27% and 54.60%, respectively). These findings allow identifying possible applications for these polysaccharides in the food industry.
authors.affiliation: Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
authors.forename: Lina F
authors.initials: LF
authors.lastname: Ballesteros
authors.affiliation: Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cerqueira
authors.affiliation: Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
authors.forename: José A
authors.initials: JA
authors.lastname: Teixeira
authors.affiliation: Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands. Electronic address: S.I.Mussatto@tudelft.nl.
authors.forename: Solange I
authors.initials: SI
authors.lastname: Mussatto
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D003069:Coffee / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D012972:Sodium Hydroxide / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D000975:Antioxidants; D003069:Coffee; D011134:Polysaccharides; D012972:Sodium Hydroxide
keywords: Antimicrobial activity; Antioxidant capacity; Polysaccharides; Spent coffee grounds; Structural properties