Heat treatment is an important factor affecting the stability of the protein emulsion.This paper investigated the effects of different heat treatment temperature(30,50,70,80 and 90 ℃,30 min)on the physicochemical properties of tuna protein emulsion.The results showed that the emulsifying property of the heat-treated protein emulsion changed significantly compared with those without heat treatment(P＜0.05).Surface hydrophobicity,viscosity,Zeta-potential,emulsifying activity and emulsion stability of tuna protein emulsion increased first and then decreased with the rise of heat treatment temperature.Within 30～70 ℃ of heating,protein secondary structure unfolded,hydrophobic groups exposed,the viscosity of emulsion increased,the particle size of the droplet decreased and the stability of the emulsion increased.After the heating temperature exceeded 70 ℃,the protein molecules reassembled,the amino acid residues bound to the oil droplets reentered the protein interior,the droplets appeared flocculation and the emulsion became unstable.The results of SDS-PAGE illustrated that the amount of protein adsorption at the oil-water interface increased,the droplet distribution was uniform,the particle size reached the minimum value of 102.6 nm,the viscosity reached the maximum of 43.87 Pa·s at 70 ℃ for 30 min.There was no stratification in the emulsion after 28-days of storage and the emulsion had the best stability at this temperature.To sum up,appropriate heat treatment could improve the stability of the tuna protein emulsion.
维普
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