title: Non-enzymatic browning reaction of glucosamine at mild conditions: Relationship between colour formation, radical scavenging activity and α-dicarbonyl compounds production.
abstract: Glucosamine (GlcN, 5% w/v) was incubated in either phosphate buffer or ammonium hydroxide solutions at 40 and 60°C for up to 48h in order to yield caramel solutions. Non-enzymatic browning was monitored via changes in absorption at 280, 320 and 420nm and the physico-chemical properties as well as the generation of short chain α-dicarbonyl compounds were evaluated. Accumulation of GlcN autocondensation products (280nm) proceeded in parallel with the development of pre-melanoidins (320nm) and melanoidins (420nm). The reactive α-dicarbonyls were detected at temperature as low as 40°C within 3h with a maximum level of diacetyl recorded at 6h. The caramel solutions showed a high efficacy in scavenging DPPH and ABTS radicals in accordance with the increasing browning intensity. The results suggest that GlcN browning can be modulated according to the specific desired properties to produce a multi-functional food ingredient that has health-promoting effects.
authors.affiliation: Department of Agricultural, Food and Nutritional Science (AFNS) , Faculty of Agricultural, Life and Environmental Sciences (ALES), University of Alberta, 4-10 Agriculture/Forestry Centre, Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Pui Khoon
authors.initials: PK
authors.lastname: Hong
authors.affiliation: Department of Agricultural, Food and Nutritional Science (AFNS) , Faculty of Agricultural, Life and Environmental Sciences (ALES), University of Alberta, 4-10 Agriculture/Forestry Centre, Edmonton, Alberta T6G 2P5, Canada. Electronic address: mirko.betti@ualberta.ca.
authors.forename: Mirko
authors.initials: M
authors.lastname: Betti
mesh_terms: D000975:Antioxidants; D003116:Color; D005944:Glucosamine / Q000737:chemistry*; D015416:Maillard Reaction
chemical_list: D000975:Antioxidants; D005944:Glucosamine
keywords: Antioxidant activity; Caramelization; Diacetyl (PubChem CID: 650); Glucosamine; Glucosamine (PubChem CID: 439213); Glyoxal (PubChem CID: 7860); Methylglyoxal (PubChem CID: 880); The Maillard reaction; α-Dicarbonyl compounds