title: Carotenoid contents of extruded and non-extruded sweetpotato flours from Papua New Guinea and Australia.
abstract: Carotenoid contents of extruded and non-extruded flours of Papua New Guinean and Australian sweetpotato cultivars were studied, using spectrophotometry and high performance liquid chromatography (HPLC). The cultivars differed (p<0.05) in their total carotenoid and β-carotene contents, and the Original Beauregard cultivar had the highest total carotenoid and β-carotene contents among the cultivars. The spectrophotometry (84-1720 μg/g solids) method generally over-estimated the total carotenoid content compared to the more specific HPLC (23-355 μg/g solids) method. Extrusion significantly (p<0.05) decreased the ΔL(*) Hunter colour values, while the Δa(*), Δb(*), total colour change (ΔE), chroma (CR), and browning indices (BI) increased. With the extruder and screw configuration used, extrusion at 40% moisture and 300 rpm screw speed retained carotenoid maximally at more than 80%. This study reports, for the first time, carotenoids of flours from south Pacific sweetpotato cultivars, and carotenoid retention during extrusion.
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, St. Lucia 4072, Australia.
authors.forename: Joel G
authors.initials: JG
authors.lastname: Waramboi
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gidley
authors.forename: Peter A
authors.initials: PA
authors.lastname: Sopade
mesh_terms: D001315:Australia; D002338:Carotenoids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005433:Flour / Q000032:analysis*; D005511:Food Handling; D027723:Ipomoea batatas / Q000737:chemistry*; D010219:Papua New Guinea
chemical_list: D002338:Carotenoids
keywords: Carotenoid retention; Colour; Extrusion; Sweetpotato; Total carotenoids; β-Carotene