Effect of titanium dioxide on color, texture, and gelation of protein recovered from otoshimi processing waste using isoelectric precipitation

Abstract

Whiteness is a critical attribute for restructured fish products such as surimi seafood. However, the whiteness of gels made from proteins recovered from otoshimi processing waste from isoelectric solubilization precipitation is poor. The by-products or waste contain bones, scales, skin, etc. that affect gel color. Therefore, whiteness needs to be improved if marketable products are to be developed from recovered proteins. The objectives of this study were to determine effects of titanium dioxide (Ti02 ) on color, texture and gelation of gels made from isolated proteins from waste of otoshimi. Protein from waste of otoshimi were recovered with isoelectric solubilization precipitation. Ti02 was added to protein paste at 0.0-0.5 g/100 g. Ti02 at concentration O.Sg/1 OOg resulted in better whiteness of protein gels than commercial surimi gels. But the texture properties of protein gels with addition of Ti02 was poor as compared to commercial surimi gel. This research demonstrates that whiteness of restructured fish products based on proteins recovered from otoshimi processing waste by isoelectric solubilization precipitation was comparable with the whiteness of commercial surimi.