The bactericidal effect of furylfuramide [2-2(furyl)-3-(5-nitro-2-furyl) acrylamide; FF], a newly permitted food preservative in Japan has been examined. And results obtained may be summarized as follows:
1. Bactericidal effects of FF and nitrofurazone (NFS) were compared each other by the official phenol coefficient method4). S. typhi was killed off with FF at a dilution equivalent 1:10, 000 in 5 minutes which corresponded to 120 in terms of phenol coefficient number. To the contrary, NFS with 1:5, 000 dilution exhibited almost no killing effect on the same test organism in 120 minutes (Tables 1 to 3).
2. Bactericidal activities of FF and NFS against E. coli and Staph. aureus were measured at their growing stage in the nutrient broth containing varying concentrations of each of the drugs and exposed for different period of time. As shown in Fig. 1, E. coli was killed off with more than 0.2 ppm of FF, and Staph. aureus with more than 1.6 ppm of the drug within 6 hours of incubation. To the contrary, no marked killing effect could be seen with NFS even at 200 ppm (Fig. 2).
3. Similar bactericidal effects on the growing stage of E. coli and Staph. aureus were noted with FF which had been added to the tuna flesh infusion, however, the efficacy was slightly lowered as compared with that observed in the nutrient broth (Fig. 3).