Preservation of fresh noodles by irradiation

At the present paper, it is studied to preserve fresh noodles by irradiation. The noodles which were irradiated by 10 kGy of ⁶⁰Co-γ rays and stored at room temperature (18–24°C). The appearance of the noodles was observed, the bacteria in the noodles were examines, and the acidity of the noodles was measured during 10 days after irradiation. The results showed that the number of bacteria and the extent of acidification of the noodles were in inverse proportion to radiation dose. When the absorbed dose was less than 8 kGy, the residual bacteria in the noodles could proliferate massively in several days and acidified the noodles. The pH of these noodles decreased from 6.2 to 5.0 or less and the noodles turned into sticky during storage. When the absorbed dose reached 8–10 kGy, most of bacteria were killed and the acidity of the noodles kept about pH 6.0. The appearance of the noodles looks fresh within 10 days after irradiation. They smelled as good as fresh ones.