Abstract
The effects of CO2 and N2 gas and ethanol on the preservation and microflora of packed "Udon" (unboiled Japanese noodles) and "Chuka-men" (Chinese noodles) were studied. Total bacterial counts of unboiled "Udon" packed in CO2 or N2 gas and unboiled "Chuka-men" packed in N2 gas were lower than those packed in air. Though the bacterial growth were suppressed by high pH (9.5-10.0) on unboiled "Chuka-men", total bacterial counts of noodles packed in CO2 gas were higher than those packed in air because of lower pH caused by absorption of CO2 gas. CO2 and N2 gas tend to inhibit the growth of Gram negatives and fungi. Ethanol tends to inhibit the growth of Gram negatives, and the growth of coli-forms were almost inhibited when the concentration of ethanol was 2% in noodles. Streptococcus was found to be the dominant flora during the preservation of unboiled noodles to which ethanol was added and packed with CO2 or N2 gas. Such tendency was remarkable in unboiled "Chuka-men".
