title: Optimisation of Ultrasound-Assisted Extraction Conditions for Phenolic Content and Antioxidant Capacity from Euphorbia tirucalli Using Response Surface Methodology.
abstract: Euphorbia tirucalli (E. tirucalli) is now widely distributed around the world and is well known as a source of traditional medicine in many countries. This study aimed to utilise response surface methodology (RSM) to optimise ultrasonic-assisted extraction (UAE) conditions for total phenolic compounds (TPC) and antioxidant capacity from E. tirucalli leaf. The results showed that ultrasonic temperature, time and power effected TPC and antioxidant capacity; however, the effects varied. Ultrasonic power had the strongest influence on TPC; whereas ultrasonic temperature had the greatest impact on antioxidant capacity. Ultrasonic time had the least impact on both TPC and antioxidant capacity. The optimum UAE conditions were determined to be 50 °C, 90 min. and 200 W. Under these conditions, the E. tirucalli leaf extract yielded 2.93 mg GAE/g FW of TPC and exhibited potent antioxidant capacity. These conditions can be utilised for further isolation and purification of phenolic compounds from E. tirucalli leaf.
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. van.vuong@uon.edu.au.
authors.forename: Quan V
authors.initials: QV
authors.lastname: Vuong
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. chloe.d.goldsmith@uon.edu.au.
authors.forename: Chloe D
authors.initials: CD
authors.lastname: Goldsmith
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. trung.dang@uon.edu.au.|Faculty of Food Technology, Nha Trang University, No. 2 Nguyen Dinh Chieu, Nha Trang, Khanh Hoa 8458, Vietnam. trung.dang@uon.edu.au.
authors.forename: Trung Thanh
authors.initials: TT
authors.lastname: Dang
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. vantang.nguyen@uon.edu.au.|Faculty of Food Technology, Nha Trang University, No. 2 Nguyen Dinh Chieu, Nha Trang, Khanh Hoa 8458, Vietnam. vantang.nguyen@uon.edu.au.
authors.forename: Van Tang
authors.initials: VT
authors.lastname: Nguyen
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. deepjyoti.bhuyan@uon.edu.au.
authors.forename: Deep Jyoti
authors.initials: DJ
authors.lastname: Bhuyan
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. elham.sadeqzadeh@newcastle.edu.au.
authors.forename: Elham
authors.initials: E
authors.lastname: Sadeqzadeh
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. c.scarlett@newcastle.edu.au.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Scarlett
authors.affiliation: Pancreatic Cancer Research, Nutrition Food & Health Research Group, School of Environmental and Life Sciences, University of Newcastle, NSW 2258, Australia. michael.bowyer@newcastle.edu.au.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Bowyer
keywords: Euphorbia tirucalli; antioxidant; optimization; phenolic compounds; response surface methodology; ultrasonic-assisted extraction