Bacteriocin produced by Enterococcus faecium NKR-5-3 isolated from Thai fermented fish was characterized and purified. According to its physical and chemical properties, E. faecium NKR-5-3 produced heat tolerant bacteriocin with broad spectrum activity against indicator strains. Treatment of bacteriocin in cell-free neutralized supernatant (CFNS) with some proteases eliminated or reduced its activity, suggesting it is proteinaceous. Furthermore, it was stable in 0 to 24% NaCl, heat tolerant at pH 2 to 10 and bactericidal toward Enterococcus faecalis ATCC 19433 T . Two antibacterial peptides, named enterocin NKR-5-3A and enterocin NKR-5-3B, were purified from the culture supernatant by four steps of column chromatography. Enterocin NKR-5-3A had the same mass, MW=5,241, and N-terminal amino acid sequence as brochocin A produced by Brochothrix campestris ATCC 43754, suggesting it may be identical to brochocin A. Enterocin NKR-5-3B exhibited MW=6,320, but its N-terminal amino acid sequence could not be determined. When these two purified peptides were mixed in a 1:1 ratio, the bacteriocin activity reached a maximum, which corresponded to 64 times the total calculated bacteriocin activity in the mixture, suggesting their synergism.

Nham-Pla (fermented sour fish cakes) were made from four kinds of fish, namely, striped catfish and nile tilapia from the fresh water fish and threadfin bream and barracuda from the marine fish. Sensory evaluation tests showed that Nham-Pla made from the fresh water fish have a higher acceptability score; and score differences between catfish and nile tilapia are insignificant. However, score differences between threadfin bream and barracuda are noticeably large. Chemical analysis and Microbiological analysis have also been performed. Results indicated that the range of pH readings

The effect of potassium bromate and egg white on gel forming ability (gel strength, pH, and folding test) of threadfin breams and mixed species surimi was studied. Effect of one and two-step heating was also studied. It was found that potassium bromate at 0.05, 0.10, 0.15, 0.20 and 0.25 kg/100 kg surimi could increase gel strength of both surimi. The highest gel strength values obtained in threadfin breams and mixed species surimi were at 0.20 and 0.25 kg/100 kg potassium bromate, respectively. For egg white, the concentrations used in the study were 1, 2, 3, 4 and 5 kg/100 kg surimi. The highest gel strength was obtained with 3 and 3-4 percent in threadfin breams and mixed species surimi, respectively. Both potassium bromate and egg white slightly lowered pH of both surimi. Change in folding test was small and the same trend was observed for gel strength.Use of potassium bromate in combination with egg white gave synergistic effect in gel strength when compared with either potassium bromate or egg white alone. The highest gel strength was obtained at 3-4 percent egg white and 0.20-0.25 percent potassium bromate.The higher gel strength was obtained with two-step heating in surimi with potassium bromate, egg white or potassium bromate combined with egg white. 163