title: Binary solvent extraction system and extraction time effects on phenolic antioxidants from kenaf seeds (Hibiscus cannabinus L.) extracted by a pulsed ultrasonic-assisted extraction.
abstract: The aim of this study was to determine the best parameter for extracting phenolic-enriched kenaf (Hibiscus cannabinus L.) seeds by a pulsed ultrasonic-assisted extraction. The antioxidant activities of ultrasonic-assisted kenaf seed extracts (KSE) were determined by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay, β -carotene bleaching inhibition assay, and ferric reducing antioxidant power (FRAP) assay. Total phenolic content (TPC) and total flavonoid content (TFC) evaluations were carried out to determine the phenolic and flavonoid contents in KSE. The KSE from the best extraction parameter was then subjected to high performance liquid chromatography (HPLC) to quantify the phenolic compounds. The optimised extraction condition employed 80% ethanol for 15 min, with the highest values determined for the DPPH, ABTS, and FRAP assay. KSE contained mainly tannic acid (2302.20 mg/100 g extract) and sinapic acid (1198.22 mg/100 g extract), which can be used as alternative antioxidants in the food industry.
authors.affiliation: Department of Food Science and Nutrition, Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, 56000 Cheras, Kuala Lumpur, Malaysia.
authors.forename: Yu Hua
authors.identifier: 0000-0002-8247-2807
authors.initials: YH
authors.lastname: Wong
authors.affiliation: Department of Food Science and Nutrition, Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, 56000 Cheras, Kuala Lumpur, Malaysia.
authors.forename: Hwee Wen
authors.initials: HW
authors.lastname: Lau
authors.affiliation: Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
authors.forename: Chin Ping
authors.identifier: 0000-0003-4177-4072
authors.initials: CP
authors.lastname: Tan
authors.affiliation: Malaysian Agricultural Research & Development Institute (MARDI), 43400 Serdang, Selangor, Malaysia.
authors.forename: Kamariah
authors.identifier: 0000-0002-3785-2106
authors.initials: K
authors.lastname: Long
authors.affiliation: Department of Food Science and Nutrition, Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights, 56000 Cheras, Kuala Lumpur, Malaysia.
authors.forename: Kar Lin
authors.initials: KL
authors.lastname: Nyam
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D005591:Chemical Fractionation / Q000379:methods*; D031584:Hibiscus / Q000737:chemistry*; D010636:Phenols / Q000302:isolation & purification*; D013010:Sonication / Q000379:methods*
chemical_list: D000975:Antioxidants; D010636:Phenols