Self-stabilizing performance of γ-oryzanol in oil-in-water emulsions and solid dispersions

Noamane Taarji; Meryem Bouhoute; Lorena de Oliveira Felipe; Mansour Sobeh; Isao Kobayashi; Marcos A Neves; Kenichi Tominaga; Hiroko Isoda; Mitsutoshi Nakajima

doi:10.1016/j.heliyon.2023.e19677

Self-stabilizing performance of γ-oryzanol in oil-in-water emulsions and solid dispersions

Heliyon. 2023 Aug 31;9(9):e19677. doi: 10.1016/j.heliyon.2023.e19677. eCollection 2023 Sep.

Authors

Noamane Taarji^{1

2

3}, Meryem Bouhoute¹, Lorena de Oliveira Felipe⁴, Mansour Sobeh³, Isao Kobayashi^{1

5}, Marcos A Neves⁶, Kenichi Tominaga², Hiroko Isoda^{1

2

6}, Mitsutoshi Nakajima^{1

2

6}

Affiliations

¹ Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-0006, Japan.
² Food and Medicinal Resource Engineering Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5-2, Tsukuba City, Ibaraki, 305-8565, Japan.
³ College of Sustainable Agriculture & Environmental Sciences, AgroBioSciences Program, Mohammed 6 Polytechnic University (UM6P), Benguerir, 43150, Morocco.
⁴ Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-0006, Japan.
⁵ Food Research Institute, NARO, 2-1-12 Kannondai, Tsukuba, 305-8642, Japan.
⁶ Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.

Abstract

The surface activity of γ-oryzanol was evaluated by the pendant drop method (PDM), and its self-stabilizing properties were investigated by high-pressure homogenization (HPH) and solvent displacement method (SDM). Emulsions prepared by HPH were highly unstable due to the poor surface-active character of γ-oryzanol as identified by the PDM. In contrast, solid dispersions fabricated by SDM had comparable particle size to those prepared using Tween 80 (T80) as surfactant, and were stable up to 30 days of storage at 4 °C. The self-stabilizing properties of γ-oryzanol were attributed to the mechanism of spontaneous particle formation in SDM and to the ability of γ-oryzanol molecules to prevent particles aggregation by electrostatic repulsion. The outcome of this study indicates the potential of encapsulating selected bioactive compounds, such as γ-oryzanol, in stable colloidal systems by SDM without adding emulsifier(s), regardless of their surface-active character.

Keywords: Dispersion; Emulsion; Encapsulation; High-pressure homogenization; Solvent displacement method; γ-Oryzanol.