title: Physicochemical properties of whey protein, lactoferrin and Tween 20 stabilised nanoemulsions: Effect of temperature, pH and salt.
abstract: Oil-in-water nanoemulsions were prepared by emulsification and solvent evaporation using whey protein isolate (WPI), lactoferrin and Tween 20 as emulsifiers. Protein-stabilised nanoemulsions showed a decrease in particle size with increasing protein concentration from 0.25% to 1% (w/w) level with Z-average diameter between 70 and 90 nm. However, larger droplets were produced by Tween 20 (120-450 nm) especially at concentration above 0.75% (w/w). The stability of nanoemulsions to temperature (30-90°C), pH (2-10) and ionic strength (0-500 mM NaCl or 0-90 mM CaCl2) was also tested. Tween 20 nanoemulsions were unstable to heat treatment at 90°C for 15 min. WPI-stabilised nanoemulsions exhibited droplet aggregation near the isoelectric point at pH 4.5 and 5 and they were also unstable at salt concentration above 30 mM CaCl2. These results indicated that stable nanoemulsions can be prepared by careful selection of emulsifiers.
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand; School of Food and Nutrition, Massey University, Palmerston North, New Zealand.
authors.forename: Anges
authors.initials: A
authors.lastname: Teo
authors.affiliation: School of Food and Nutrition, Massey University, Palmerston North, New Zealand.
authors.forename: Kelvin K T
authors.initials: KK
authors.lastname: Goh
authors.affiliation: School of Pharmacy, University of Auckland, New Zealand.
authors.forename: Jingyuan
authors.initials: J
authors.lastname: Wen
authors.affiliation: Department of Food Science, University of Otago, Dunedin, New Zealand.
authors.forename: Indrawati
authors.initials: I
authors.lastname: Oey
authors.affiliation: Department of Food Science and Technology, Sejong University, Seoul, Republic of Korea.
authors.forename: Sanghoon
authors.initials: S
authors.lastname: Ko
authors.affiliation: Department of Food Science and Technology, Sejong University, Seoul, Republic of Korea.
authors.forename: Hae-Soo
authors.initials: HS
authors.lastname: Kwak
authors.affiliation: School of Food and Nutrition, Massey University, Auckland, New Zealand. Electronic address: s.j.lee@massey.ac.nz.
authors.forename: Sung Je
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D055598:Chemical Phenomena; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D007781:Lactoferrin / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011136:Polysorbates / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D013696:Temperature; D000067816:Whey Proteins / Q000737:chemistry*
chemical_list: D004655:Emulsions; D011136:Polysorbates; D000067816:Whey Proteins; D012965:Sodium Chloride; D007781:Lactoferrin
keywords: High pressure homogenisation; Lactoferrin; Nanoemulsions; Physicochemical properties; Solvent evaporation; Tween 20; Whey protein isolate (WPI)