The Emulsion characteristic of gelatin fraction from tilapia (Oreochromis niloticus) skin

Fractionation of gelatin extract from tilapia (Oreochromis niloticus) skin was done by using dialysis bag of MWCO 100 kD. The aim of this research was to determine the emulsion characteristics of gelatin fraction from the process of 0.10 M acetic acid (GAs) and 0.05M citric acid (GSi). Gelatin GAs fraction has a molecular weight distribution of 13.6 to 218.87 kD and 15.27 to 61.1 kD while gelatin GSI fraction of 107.5 to 142.23 kD and 12.5 to 82.9 kD. Functional groups of the four fractions of gelatin molecules consist of amide I (1648 cm-1), amide II (1452 cm-1) and amide III (1089 cm-1). Emulsion characteristics including the emulsion properties (activity and stability of emulsion) and particle size emulsion increased with the increasing of molecular weight. Zeta potential of emulsion droplet gelatin from 0.05M citric acid (GSi) method produced more positively charged ions than 0.10 M acetic acid process (GAs). Emulsion created by 0,1% GAs and GSi fraction was refer to macroemulsion with droplet size >100 nm and stability 22.62 minutes, which could be applied for food product such as ice cream, whipping cream and salad dressing.