Adhesion inhibitory effects of food additives, such as Polylysine (PL) and Whey protein (WP), as well as Sucrose fatty acid ester (SFE) with fatty acid of C8 to C18, Monoglycerin fatty acid ester (MFE) with fatty acid of C8 to C18, Gardenia yellow pigment (GY), Monascus pigment (MP), and Protamine (PT) that had been shown to inhibit adhesion of Salmonella Enteritidis onto microtiter plate, were determined on several bacteria. Among SFE tested, adhesion of S. Typhimurium onto microtiter plate was decreased to less than 50% of the control by SFE with fatty acid of C10, C12, C14, and C16 at 0.05% and that of C18 at 0.01%. MFE with fatty acid of C8, C10, C12, C16, C18 also inhibited the adhesion to less than 50% of the control. The adhesion of S. Typhimurium was also almost completely inhibited by PT and PL at 0.01%, 0.1% MP, 0.025% WP, and 1% GY. Adhesion of Pseudomonas aeruginosa was decreased to less than 50% of the control by SFE with C8 and C16 fatty acid at 0.05%, C12 and C14 at 0.01%, 0.1% PT, 0.01% PL, and 0.025% WP, but not by 0.05% MFE tested, 1% GY, and 1% MP. Adhesion of P. fluorescens was almost completely inhibited by SFE with fatty acid of C14, C16, and C18 at 0.05, 0.005, and 0.005%, respectively, and 1% GY, 1% MP, 0.1% PT, and 1% PL, but not by MFE and WP even at 0.05 and 0.25%, respectively. Adhesion of Listeria monocytogenes was decreased to less than 50% of the control by SFE with fatty acid of C10, C12, C16, and C18 at 0.05% and by MFE with fatty acid of C10, C14, C16, and C18 at 0.05, 0.05, 0.005, and 0.005, respectively. The adhesion decreased to less than 50% of the control by 0.1% MP, 1% PT, and 1% PL, but not by 1% GY and 0.25% WP. Adhesion of Staphylococcus aureus decreased to less than 50% of the control by SFE with fatty acid of C10, C12, C14, C16, and C18 at 0.05, 0.01, 0.005, 0.005, and 0.005%, respectively. The adhesion was inhibited by more than 50% by 0.05% MFE with C8 fatty acid and by 0.005% MFE with C10 to C18 fatty acid. GY, MP, PT, PL, and WP decreased the adhesion by more than 50% at 0.1, 0.01, 0.01, 0.01, and 0.025%, respectively. It seems to be important to select suitable substances for inhibition of adhesion of each of the bacterial species.
Kamaboko (steamed surimi) is manufactured by gelling surimi, which is a refined fish protein product. Contamination by Leuconostoc sp. and Enterococcus sp. reduce the shelf-life of kamaboko products during preservation. Particularly, L. mesenteroides produces dextran, called “neto”, on kamaboko and lowers the quality of kamaboko products. Bacteriocins produced by lactic acid bacteria (LAB) were screened for potential use in the control of contamination by Leuconostoc sp. and Enterococcus sp., and the results showed that the bacteriocin produced by Carnobacterium maltalomaticum, which was a strain isolated from the intestine of a herring, had the ability to inhibit these bacteria. The screened bacteriocin was purified by several chromatography steps, and part of its structure was determined. The primary structure of this bacteriocin (called piscicolin KH1) was similar to that of piscicolin 126. Piscicolin KH1 had a strong ability to inhibit E. faecium and L. mesenteroides. Kamaboko samples containing piscicolin KH1 and/or nisin, which is a commonly used food preservative, were prepared, and growth of E. faecium and L. mesenteroides was monitored during preservation at 10°C. The results showed that bacterial growth was significantly inhibited on kamaboko containing piscicolin KH1. Piscicolin KH1 appeared to be more effective than nisin in inhibiting bacterial grown.