title: Development of pressurised hot water extraction (PHWE) for essential compounds from Moringa oleifera leaf extracts.
abstract: Pressurised hot water extraction (PHWE) is a "green" technology which can be used for the extraction of essential components in Moringa oleifera leaf extracts. The behaviour of three flavonols (myricetin, quercetin and kaempferol) and total phenolic content (TPC) in Moringa leaf powder were investigated at various temperatures using PHWE. The TPC of extracts from PHWE were investigated using two indicators. These are reducing activity and the radical scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). Flavonols content in the PHWE extracts were analysed on high performance liquid chromatography with ultra violet (HPLC-UV) detection. The concentration of kaempferol and myricetin started decreasing at 150 °C while that of quercetin remained steady with extraction temperature. Optimum extraction temperature for flavonols and DPPH radical scavenging activity was found to be 100 °C. The TPC increased with temperature until 150 °C and then decreased while the reducing activity increased.
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa.
authors.forename: Phatsimo G
authors.initials: PG
authors.lastname: Matshediso
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa.
authors.forename: Ewa
authors.initials: E
authors.lastname: Cukrowska
authors.affiliation: Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg, South Africa. Electronic address: luke.chimuka@wits.ac.za.
authors.forename: Luke
authors.initials: L
authors.lastname: Chimuka
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D006358:Hot Temperature; D044949:Kaempferols / Q000032:analysis; D029588:Moringa oleifera / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D011312:Pressure; D011794:Quercetin / Q000032:analysis; D014867:Water / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D044949:Kaempferols; D010636:Phenols; D010936:Plant Extracts; D014867:Water; C006552:kaempferol; C040015:myricetin; D011794:Quercetin
keywords: DPPH; Flavonols; Moringa oleifera; PHWE; Total phenolic content