Freeze-thaw Stability of Oil-in-water Prepared with Soy Protein Isolate-maltodextrin Conjugates

The objective of the study was to investigate the impact of soy protein isolate (SPI)-maltodextrin conjugates on the freeze-thaw stability of oil-in-water emulsions. Covalent coupling of maltodextrin to SPI was achieved by wet heating of SPI- maltodextrin mixtures of different weight ratios and different protein contents at 70,80,90,100 degrees C for 1 to 5 h. The freeze-thaw stability was characterized by measurements of creaming index and oiling off after isothermal storage at -20 degrees C for 24 h and further thawing. Compared with those stabilized by SPI alone, o/w emulsions stabilized by SPI-maltodextrin conjugates showed a higher stability against freeze-thaw treatment, exhibiting a lower creaming index and oiling off.