This study was designed to investigate the growth of Streptomyces griseus and Streptomyces odorifer, their production of and the distribution of musty odor compounds in white potato and cornmeal bread. Total plate count and actinomycetes /cm('2) where determined before and after storage for 3 or 5 days at 30 (+OR-) 3(DEGREES)C. A sensory panel was trained to identify musty odor. Musty odor compounds were extracted with organic solvents prior to analysis by gas chromatography and mass spectrometry. / There was a significant difference (p < 0.01) in total plate count before and after storage of both the treated and untreated potato and bread samples. However, there was no significant difference in total plate count of the samples treated with S. griseus compared with those treated with S. odorifer. Inner layers exhibited significantly lower growth when examined for total plate count and actinomycetes in all samples. Actinomycetes represented only 11-14% of the total plate count after storage. / Retention times for geosmin and 2-methyl-isoborneol were determined by analyzing the gas chromatography and mass spectrometry data. No increase in peak height of geosmin or 2-methyl-isoborneol resulted when the food sample was added to standards. Further analysis of the mass spectra showed geosmin and 2-methyl-isoborneol peaks to be absent from the food sample. These results were the same for both strains in potatoes and bread. It was concluded that the actinomycetes in this study did not produce geosmin or 2-methyl-isoborneol in detectable quantities. / Foods treated with S. griseus or S. odorifer received significantly higher scores (p < 0.05) for musty odor than control samples; however, there was no significant difference in scores between S. griseus and S. odorifer. There was no significant difference in odor between inner layers of treated and control samples of bread or potatoes. The offensive odor that developed on outer layers was believed to be a mixture of musty and other offensive compounds produced by spoilage aerobes. / Source: Dissertation Abstracts International, Volume: 44-12, Section: B, page: 3705. / Thesis (Ph.D.)--The Florida State University, 1983.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75257 |
| Contributors | ABO-GNAH, YAHYA S., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 157 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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