Emulsifying properties of homogenised soybean hull suspensions as stabilisers for oil/water emulsions

Abstract

Summary In this work, the structural characteristics, physicochemical properties, and emulsifying properties of soybean hull suspension treated by high pressure homogenisation (HPH) were investigated. HPH significantly reduced the average particle size of pre‐ground soybean hulls (from 125.80 μm to 37.27 μm) and changed the shape of the particles from an irregular block‐like structure to a multi‐branched flake‐like structure. The resulting soybean hull particles increased water‐ and oil‐holding capacities (WHC and OHC), and improved particle wettability. Moreover, the viscosity and emulsifying properties of soybean hull suspension increased with increased homogenisation cycles. Oil/water (O/W) emulsions prepared with aqueous soybean hull suspensions of up to 2% (w/v) were resistant to emulsion coalescence, the droplet size was <10 μm and did not change significantly during 30 days of storage. The rheological measurements showed that the emulsions had predominantly gel‐like characteristics. These findings indicated that soybean hulls treated with HPH had good emulsifying and stabilising properties for O/W emulsions, which provided practical guidance on the high value‐added utilisation of soybean hull.