Effects of deodorization by powdered activated carbon, β-cyclodextrin and yeast on odor and functional properties of tiger puffer (Takifugu rubripes) skin gelatin

The study investigated odor, physiochemical and functional properties of tiger puffer skin gelatin (TPSG) deodorized by powdered activated carbon (PAC, 0.5%), β-cyclodextrin (βCD, 3%) and yeast fermentation (YEF, 1%). Sensory test and electronic nose analysis exposed that three treatments lowered fishy odor intensity, coincided with decreased categories and levels of volatile compounds. Amide I, II and B of group βCD were shifted to lower wavenumber and amplitudes of amide bands in group YEF were much lower than those of others. Gel strength of group βCD and YEF declined, coincided with their higher relaxation time (component T22 and T2b) (p < 0.05). Marked decreases in gelling and melting temperature were found in group βCD. Emulsion activity index of group YEF decreased (p < 0.05) while emulsion stability index of all deodorized groups increased (p < 0.05). Different from uneven clusters with large size emulsion droplets in control, a homogenous system with small size droplets was observed in group YEF. PAC filtration increased clarity and lowered b* value (p < 0.05), but βCD treatment greatly decreased clarity (p < 0.05). Results suggest that YEF and βCD treatment deteriorated physical and functional properties of TPSG. Nevertheless, PAC filtration reduced fishy odor without compromising physiochemical and functional properties and is recommended for TPSG deodorization.