Octenyl succinic anhydride modification of bovine bone and fish skin gelatins and their application for fish oil-loaded emulsions

Abstract

Molecular modification of emulsifiers has attracted many attentions in the field of emulsions. In this work, an octenyl succinic anhydride (OSA) modification method is developed to modify bovine bone gelatins and fish skin gelatins, and then the effect of OSA modification on the gelatins and their application for fish oil-loaded emulsions are explored and compared. The results demonstrate that OSA can be successfully applied to modify gelatins and change their isoelectric points. Moreover, the degree of succinylation (DS) logarithmically increases with OSA-gelatin mass ratios in the chemical reaction process. Further, the OSA modification has no obvious effects on the initial emulsion droplet sizes of fish oil-loaded emulsions. Finally, the emulsion storage experiments suggest that the DS increase of OSA-modified bovine bone gelatins increases the droplet stability, phase transition time, and creaming index of fish oil-loaded emulsions, whereas the DS increase of OSA-modified fish skin gelatins only increases the droplet stability and has no obvious effects on the phase transition and creaming index of fish oil-loaded emulsions. This work will provide useful information to understand the relationship among molecular modification, molecular structure, and function of protein. It also will provide a potential route to optimize the preparation and application of fish oil-loaded emulsions in the field of food and drug industries.