煉製品

In the previous papers, it was reported that the casing with cellophane, the irradiation by infrared and/or ultraviolet ray showed a marked prolongation of shelf-life of " Kamaboko ". It was further noticed that when the preservatives were smeared on the surface, the combination of the preservatives and casing was rather inferior to the control group without casing. However, when the preservatives were mixed with the paste, the combination did not show any inferior effect to the control. The present paper deals with a comparison of the effectiveness between preservatives which were mixed with the paste and those which were applied on the surface, and further with the effectiveness of casing with cellophane, polyvinyl alcohol and polyvinyl acetate film and of infrared and/or ultraviolet ray irradiation all over the surface of "Kamaboko". 1. When the preservatives were mixed with the paste, dehydroacetic acid and its sodium salt were effective in prolonging the storage life to six and four days, respectively, in contrast to two days in the control at 26℃. However, the preservatives which were smeared on the surface were not effective (See Tables 1 and 2). 2. Among the preservatives which were mixed with the "Kamaboko", butyl p-hydroxybenzoate and o-hydroxybenzamide showed effectiveness to some extent on keeping quality (See Table 3). 3. The casing with polyvinyl alchol film gave rather an inferior result. The combination of the casing with polyvinyl alcohol film and the mixing with preservatives shortened the shelf-life compared to the control (See Table 4). 4. In the case of " Kamaboko " without the casing, irradiation by the infrared ray for short time prevented the growth of bacteria. However, irradiation by ultraviolet ray showed remarkable effect on inhibition of bacterial growth. Irradiation by ultraviolet ray twice daily was slightly more effective than that once daily. The combination of irradiation by ultraviolet ray twice daily and that by infrared ray every other day was effective in prolonging the storage life to five days in contrast to two days in the control without the irradiation (See Table 5, Figs. 1a, 1b and 1c). 5. Irradiation by ultraviolet ray over " Kamaboko " which was covered with cellophane or polyvinyl cetate was also effective. No difference was observed between the irradiation once daily and twice daily (See Table 6, Figs. 1a, 1b and 1c). 6. Daily irradiation by ultraviolet ray all over the surface of "Kamaboko" which contained DHA at a 0.1 % level and covered with cellophane or polyvinyl acetate was able to prolong the storage life to 10 days in contrast to a storage life of two days in the control at 26℃ (See Tables 7 and 8).