Effect of heat treatment on the properties of surimi gel from black mouth croaker (Atrobucca nibe).
The aim of this study was to evaluate the physicochemical characteristics of surimi gel-forming ability due to different heating conditions. Textural properties, whiteness, expressible moisture, microstructure and protein pattern of the gel specimens were determined. All gel samples were incubated for 18 hours at 4°C before applying for analyses. Kamaboko gel (KK) by setting sol at 40°C prior to cooking at 90°C for 20 min showed the highest breaking force (623.20±21.74 g), followed by directly heated (DH) and modori (MD) gels, respectively (p<0.05). The highest expressible moisture (5.269±0.09%) and whiteness (73.91±0.02%) were found in DH gel (p<0.05). Conversely, two-steps heated gels (i.e. KK and MD) showed lowest expressible drip and whiteness (p<0.05). KK had the higher interconnected three-dimensional protein networks than other gels. High Hardness (1.6-3.8 Kg force) and deformation (10.73 to 12.06 mm) of black mouth croaker surimi gels, introduce that this low fat and white-fleshed fish species could be used for producing high quality surimi-based products. Analysis of SDS- PAGE indicated that myosin heavy chain (MHC) as a major protein with a high density band in surimi, decreased in all gels. However, MHC was more retained in DH gel. In conclusion, preparation of KK enhanced the gel-forming properties of surimi.