| Summary: | 碩士 === 國立臺灣海洋大學 === 食品科學系 === 98 === The objective of this study is to investigate the hygienic qualities and physico-chemical properties of commercial ready-to-eat (RTE) chilled noodle products. Eighty one RTE noodle samples purchased from chain store, street vendor and noodle store in Taipei area on Sep. 2009 - Mar. 2010 were examined. The moisture content of commercial chilled noodles ranged from 52.6% to 69%, and Aw from 0.972 to 0.984. The products had light yellow appearance with “L” value from 93.1 to 95.37, “a” value from -15.63 to -22.27, “b“ value from 28.62 to 44.98, and white index from 49.2 to 67.19. Regarding microbiological quality, there were 48 samples (59.26%) unqualified in total plate count that was over the limit of 105 CFU/g. Only one of 29 chain store samples was over the limit value, but the unqualified percentage for the samples from noodle store even reached 94.74%. The unqualified sample number for coliform content over 103 MPN/g was 44 (54.32%). Especially the unqualified samples from street vendor and noodle store reached 50% and 97.37%. A total of 81 samples detection rates for the presence of Escherichia coli and Staphylococcus aureus were 17.28% and 20.99%, respectively. The unqualified samples in total plate count, coliform, E. coli and S. aureus for samples purchased form street vendor and noodle store were significantly higher than those from chain store. Both storage temperature and period significantly affected the total plate count of chilled noodle food. Based on the result of the storage test of the self-made RTE noodle, the self-life of the product was less than 12 h during storage at 35℃, less than 24 h at 25℃, and 36 h for 15℃ storage. The total plate count was not detectable (below 2 log CFU/g) for samples stored at 4℃ for 4 days. The pH values of commercial chilled noodles ranged from 5.15 to 10.0, and most were at 6-7 and 9-10. The products might be added Na2CO3 and K2CO3, and resulted in higher pH values. The products with higher pH values had higher extension tread, and also had lower microbiological counts. Hydrogen peroxide detection of all the samples was negative.
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