Effect of ethanolic coconut husk extract and pre-emulsification on properties and stability of surimi gel fortified with seabass oil during refrigerated storage

The impact of ethanolic coconut husk extract (ECHE) at different concentrations (0-0.25 g extract/100 g surimi) and pre-emulsification on the properties and stability of sardine (Sardinella albella) surimi gel fortified with seabass oil during refrigerated storage of 10 days were investigated. Addition of seabass oil pre-emulsified with soy protein isolate (SPI) in the presence of 0.20-0.25 g ECHE/100 g, which had the average major mean diameter (d(43)) of 17.18-33.01 mu m, yielded the gel possessing the highest breaking force with the coincidental increases in hardness, chewiness, gumminess and cohesiveness (P < 0.05). Decrease in whiteness was noticeable in surimi gel added with ECHE, especially with increasing ECHE levels (P < 0.05). When the gels containing ECHE at various concentrations were stored at 4 degrees C for 10 days, lipid oxidation as determined by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) of surimi gel was lowered as the levels of ECHE increased (P < 0.05). Nevertheless, addition of ECHE did not affect total viable count and psychrophilic bacterial count in surimi gels. Thus, the incorporation of seabass oil pre-emulsified using SPI in combination with ECHE (0.2-0.25 g/100 g) could improve textural properties and oxidative stability of sardine surimi gels but did not restrict microbial proliferation.