The effect of alkaline extraction and drying techniques on the physicochemical, structural properties and functionality of rice bran protein concentrates

Int J Biol Macromol. 2023 Jul 1;242(Pt 3):124908. doi: 10.1016/j.ijbiomac.2023.124908. Epub 2023 May 20.

Abstract

Rice bran protein concentrates (RBPC) were extracted using mild alkaline solvents (pH: 8, 9, 10). The physicochemical, thermal, functional, and structural aspects of freeze-drying (FD) and spray-drying (SD) were compared. FD and SD of RBPC had porous and grooved surfaces, with FD having non-collapsed plates and SD being spherical. Alkaline extraction increases FD's protein concentration and browning, whereas SD inhibits browning. According to amino acid profiling, RBPC-FD9's extraction optimizes and preserves amino acids. A tremendous particle size difference was prominent in FD, thermally stable at a minimal maximum of 92 °C. Increased pH extraction gives FD greater exposal surface hydrophobicity and positively relates to denaturation enthalpy. Mild pH extraction and drying significantly impacted solubility, improved emulsion properties, and foaming properties of RBPC as observed in acidic, neutral, and alkaline environments. RBPC-FD9 and RBPC-SD10 extracts exhibit outstanding foaming and emulsion activity in all pH conditions, respectively. Appropriate drying selection, RBPC-FD or SD potentially employed as foaming/emulsifier agent or meat analog.

Keywords: Alkaline extraction; Emulsion property; Functional property; Health-promoting food; Rice bran; Rice bran protein.

MeSH terms

  • Amino Acids
  • Emulsions / chemistry
  • Oryza* / chemistry
  • Plant Proteins / chemistry
  • Solubility

Substances

  • Emulsions
  • Plant Proteins
  • Amino Acids