Effects of gelatin-transglutaminase crosslinking, vitamin addition, and storage temperature on the properties of curcumin/fish oil-loaded emulsions

The effects of gelatin-transglutaminase (TG) crosslinking and anti-oxidant types on the stabilization of curcumin in emulsions have not been studied. This work aimed to analyze the effects of bovine bone gelatin (BBG)-TG crosslinking and vitamin (vitamin C, VC; vitamin E, VE) addition on the properties of curcumin/fish oil-loaded gelatin-stabilized emulsions. The BBG-TG was prepared via a crosslinking method and the emulsions were prepared using a homogenization method. The gelatin-TG crosslinking and low-temperature (4 ± 1 °C) storage increased, VC decreased, and VE had no obvious effect on the emulsion creaming stability. The synergetic use of gelatin-TG crosslinking with VC + VE decreased the peroxidation values at day 7 to 2.1 ± 0.2 mmol/kg oil (room temperature) and 1.6 ± 0.1 mmol/kg oil (4 ± 1 °C). The low-temperature storage induced better curcumin retention than both vitamin addition and gelatin-TG crosslinking. In the in vitro digestion process, the gelatin-TG crosslinking increased the transformation, bio-accessibility, and bio-accessibility index of curcumin, whereas it decreased accumulative released free fatty acid percentages. Vitamin addition increased the bio-accessibility and the bio-accessibility index of curcumin in the emulsions after the in vitro digestion process. This work benefited the encapsulation of curcumin and anti-oxidants (VC and VE) in oil-in-water emulsions and its application in dairy functional food development.