Sodium caseinate–maltodextrin conjugate hydrolysates: Preparation, characterisation and some functional properties

Hydrolysates of sodium caseinate (NaCN)–maltodextrin (Md40 or Md100) conjugates were prepared with a limited (<10%) and moderate (>10%) degree of hydrolysis. When assessed in the pH range 2.0–8.0, each conjugate hydrolysate had improved solubility compared to NaCN and their respective native unhydrolysed conjugate. Oil-in-water emulsions containing NaCN (1%, w/w, protein) and various combinations of conjugate hydrolysates (0.2%, w/w) and/or glycerol monostearate (0.07–0.3%, w/w, GMS) were prepared; emulsion storage stability (at 45 °C for up to 20 days) and heat stability (at 140 °C for up to 20 min) was determined by measuring changes in the mean size of fat globules in emulsions. NaCN plus conjugate hydrolysate-stabilised emulsions had improved storage stability compared to a NaCN stabilised emulsion. In general, NaCN plus conjugate hydrolysate-stabilised emulsions were less heat-stable than NaCN or NaCN plus GMS stabilised emulsions; however, emulsions stabilised by NaCN plus one of the conjugate hydrolysates (CH102) had improved heat stability in comparison to the NaCN stabilised emulsion. The results show that hydrolysates of NaCN–Md conjugates have potential for use as emulsification aids in emulsion-based food products.