Use of kiam wood extract as gel enhancer for mackerel (Rastrelliger kanagurta) surimi

P>Kiam (Cotylelobium lanceotatum craih) wood was extracted using water or ethanol. Water kiam wood extract (WKWE) and ethanolic kiam wood extract (EKWE) contained tannin at levels of 251.90 and 456.30 mg g(-1) of dry extract, respectively. Effects of WKWE and EKWE at different levels (0-0.60% of protein content) on the properties of gels from mackerel (Rastrelliger kanagurta) surimi were investigated in comparison with commercial tannin (CT). Gels added with 0.30% WKWE, 0.15% EKWE or 0.30% CT had the increases in breaking force by 134.81%, 136.09% and 121.34% and in deformation by 52.60%, 54.96% and 33.53%, respectively, compared with the control (without addition of extracts or CT). The lowered expressible moisture content and the formation of cross-linked myosin heavy chain were also observed in surimi gels incorporated with those additives. Thus, the extract of kiam wood can be used as surimi gel enhancer without affecting its sensory properties.