title: The Phase Behavior of γ-Oryzanol and β-Sitosterol in Edible Oil.
abstract: The phase behavior of binary mixtures of γ-oryzanol and β-sitosterol and ternary mixtures of γ-oryzanol and β-sitosterol in sunflower oil was studied. Binary mixtures of γ-oryzanol and β-sitosterol show double-eutectic behavior. Complex phase behavior with two intermediate mixed solid phases was derived from differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) data, in which a compound that consists of γ-oryzanol and β-sitosterol molecules at a specific ratio can be formed. SAXS shows that the organization of γ-oryzanol and β-sitosterol in the mixed phases is different from the structure of tubules in ternary systems. Ternary mixtures including sunflower oil do not show a sudden structural transition from the compound to a tubule, but a gradual transition occurs as γ-oryzanol and β-sitosterol are diluted in edible oil. The same behavior is observed when melting binary mixtures of γ-oryzanol and β-sitosterol at higher temperatures. This indicates the feasibility of having an organogelling agent in dynamic exchange between solid and liquid phase, which is an essential feature of triglyceride networks.
authors.affiliation: Laboratory of Physics and Physical Chemistry of Foods, Department of Agrotechnology and Food Sciences, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands ; Chemical Engineering Department, An-Najah National University, P.O. Box 7, Nablus, Palestine ; Environmental Technology Engineering Department, Palestine Polytechnic University, Hebron, Palestine.
authors.forename: Hassan
authors.initials: H
authors.lastname: Sawalha
authors.affiliation: Laboratory of Physics and Physical Chemistry of Foods, Department of Agrotechnology and Food Sciences, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Venema
authors.affiliation: Unilever Research and Development Vlaardingen, Olivier Van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands.
authors.forename: Arjen
authors.initials: A
authors.lastname: Bot
authors.affiliation: Unilever Research and Development Vlaardingen, Olivier Van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands ; Food Process Engineering, Department of Food Technology and Food Chemistry, Technical University Berlin, Königin-Luise-Strasse 22, 14195 Berlin, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Flöter
authors.affiliation: Unilever Research and Development Vlaardingen, Olivier Van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands.
authors.forename: Ruud den
authors.initials: RD
authors.lastname: Adel
authors.affiliation: Laboratory of Physics and Physical Chemistry of Foods, Department of Agrotechnology and Food Sciences, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van der Linden
keywords: DSC; Eutectic point; Oleogel; Organogel; Phase behavior; Phase diagram; SAXS; Solidification; Tubule; β-Sitosterol; γ-Oryzanol