Formulation and stability evaluation of water-in-fat and water-in-oil emulsions loaded with short-chain fatty acid

Abstract

This study sought to formulate water-in-fat (W/F) and water-in-oil (W/O) emulsions loaded with a short-chain fatty acid and to evaluate storage stability of these emulsions. Premixtures comprising a dispersed aqueous phase loaded with 5 wt% butyric acid and a continuous phase with a hydrophobic emulsifier were subjected to a single-pass, temperature-controlled, high-pressure homogenization at 100 MPa to formulate W/F and W/O emulsions. Submicron W/F and W/O emulsions with Sauter mean diameters d_3,2 < 0.5 μm and monomodal droplet size distributions were obtained at different weight fractions of the dispersed phase (W_d) in the range of 1–5 wt%. At a W_d of 5 wt%, the W/F emulsions maintained a consistent distribution after 4 weeks of storage and following consecutive melting–solidification cycles. The results demonstrated formulation of stable submicron W/F emulsions loaded with a short-chain fatty acid, with potential for possible applications as nutrient delivery systems to the large bowel.

Keywords:

• Short-chain fatty acid
• palm stearin
• W/O emulsion
• high-pressure homogenization
• storage stability
• crystallization