title: Monodisperse aqueous microspheres encapsulating high concentration of l-ascorbic acid: insights of preparation and stability evaluation from straight-through microchannel emulsification.
abstract: Stabilization of l-ascorbic acid (l-AA) is a challenging task for food and pharmaceutical industries. The study was conducted to prepare monodisperse aqueous microspheres containing enhanced concentrations of l-AA by using microchannel emulsification (MCE). The asymmetric straight-through microchannel (MC) array used here constitutes 11 × 104 μm microslots connected to a 10 μm circular microholes. 5-30% (w/w) l-AA was added to a Milli-Q water solution containing 2% (w/w) sodium alginate and 1% (w/w) magnesium sulfate, while the continuous phase constitutes 5% (w/w) tetraglycerol condensed ricinoleate in water-saturated decane. Monodisperse aqueous microspheres with average diameters (dav) of 18.7-20.7 μm and coefficients of variation (CVs) below 6% were successfully prepared via MCE regardless of the l-AA concentrations applied. The collected microspheres were physically stable in terms of their dav and CV for >10 days of storage at 40°C. The aqueous microspheres exhibited l-AA encapsulation efficiency exceeding 70% during the storage.
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.|b Graduate School of Agricultural and Life Sciences , The University of Tokyo , Bunkyo-ku , Japan.
authors.forename: Nauman
authors.initials: N
authors.lastname: Khalid
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Kobayashi
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.|c Faculty of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Japan.
authors.forename: Marcos A
authors.initials: MA
authors.lastname: Neves
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Uemura
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.|c Faculty of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Japan.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Nakajima
authors.affiliation: a Food Engineering Division , National Food Research Institute, NARO , Tsukuba , Japan.|b Graduate School of Agricultural and Life Sciences , The University of Tokyo , Bunkyo-ku , Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nabetani
mesh_terms: D000464:Alginates / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry*; D004339:Drug Compounding; D004655:Emulsions / Q000737:chemistry*; D019649:Food Industry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008863:Microspheres; D010316:Particle Size; D014867:Water / Q000737:chemistry*
chemical_list: D000464:Alginates; D004655:Emulsions; D006603:Hexuronic Acids; D014867:Water; D020723:Glucuronic Acid; D001205:Ascorbic Acid
keywords: high concentration; l-ascorbic acid; monodisperse microspheres; sodium alginate; stability