| 1. |
- Börjesson, Thomas S., et al.
(författare)
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Off-odorous compounds produced by molds on oatmeal agar : Identification and relation to other growth characteristics
- 1993
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Ingår i: Journal of Agricultural and Food Chemistry. - Washington : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 41:11, s. 2104-2111
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Tidskriftsartikel (refereegranskat)abstract
- Ten Penicillium and Aspergillus species, four with a strong musty off-odor and six reference fungi without any characteristic odor, were cultivated on oatmeal agar for 5 days in cultivation vessels provided with an inlet and an outlet for air. Samples of volatile metabolites were collected on a porous polymer adsorbent attached to the outlet from day 2 through day 5 after inoculation. Adsorbed compounds were desorbed thermally and analyzed with GC/MS and a combined GC and sensory analysis, the GC sniff technique. Multivariate analysis of GC/MS and fungal odor data revealed strong associations between 6 of 65 volatile compounds and musty off-odor. The GC sniff technique showed that five of these, dimethyl disulfide, 1-octen-3-ol, 2-methylisoborneol, and two C11H18 compounds, had prominent off-odors. In addition, geosmin, 1-methoxy-3-methylbenzene, and methylphenol were produced in large amounts by some off-odorous fungi and contributed to their unpleasant odor. 3-Methylfuran, 2-methyl-1-propanol, and 3-methyl-1-butanol were much more commonly produced than the off-odorous compounds. Both odorous and other volatile metabolites could be detected after 2 days of fungal growth. The production of odorous metabolites was enhanced at the time of sporulation.
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| 2. |
- Eilertz, Ingrid, et al.
(författare)
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Isolation of Listeria monocytogenes from goat cheese associated with a case of listeriosis in goat
- 1993
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Ingår i: Acta Veterinaria Scandinavica. - : Danske Dyrelaegeforening. - 0044-605X .- 1751-0147. ; 34:2, s. 145-149
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Tidskriftsartikel (refereegranskat)abstract
- Listeria monocytogenes was isolated from the brain of a goat, which was euthanized due to listeriosis. A few weeks later a similar subtype of L. monocytogenes was isolated from an on-farm manufactured fresh cheese which did not contain any milk from the goat which had suffered from listeriosis. A similar subtype was also found on 1 of the shelves in the refrigerator where cheeses were stored. Prior to the onset of listeriosis, 1 fresh cheese had been made of milk from the actual goat, which may have excreted L. monocytogenes in her milk. Thus, the cheese made of this milk may have contaminated the shelves in the refrigerator which then has served as a Listeria reservoir for new cheeses during several weeks.
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| 3. |
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Fossil åkermark
- 1991
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Schnürer, Johan, 1957-, et al.
(författare)
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Ergosterol Levels and Mould Colony Forming Units in Swedish Grains of Food and Feed Grade
- 1992
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Ingår i: Acta Agriculturae Scandinavica - Section B. - Oslo, Norway : Scandinavian University Press. - 0906-4710 .- 1651-1913. ; 42:4, s. 240-245
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Tidskriftsartikel (refereegranskat)abstract
- Although ergosterol is considered to be a suitable indicator of mould growth in cereal grains, there are few reference values available for Scandinavian conditions. We have determined the ergosterol levels in Swedish grain of different origins: cleaned food-grade wheat from a commercial mill, feed-grade cereals (oats and barley) with different odours and cereals (winter wheat, ''American wheat'', triticale and rye) from various field trials conducted in south-central Sweden in 1990. Specific objectives were to elucidate the relationships between ergosterol levels and numbers of mould colony forming units (CFU) and between ergosterol and grain odour.Ergosterol levels in the food-grade wheat ranged between 2.4 and 2.8 mug/g DW, and between 3.0 and 5.6 mug/g DW in the field trial cereals, while values in most of the feed grain samples ranged from 8-15 mug/g DW The levels agree with other published data for European grains.A positive correlation was found between numbers of colony-forming units and ergosterol concentration. The degree of correlation was higher when numbers of CFU were determined on dichloran-glycerol 18% agar with a low water activity (aw = 0.95) than on malt extract agar (aw = 0.99). There was no agreement between ergosterol levels and grain odour, since even samples described as having a fresh smell had high ergosterol levels. However, the highest level (33 mug/g DW) was found in a sample with a pronounced musty odour, and the lowest (1.1 gg/g DW) in a sample that smelled as if it had been heat damaged.
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| 5. |
- Andersson, Karin, et al.
(författare)
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Life cycle assessment (LCA) of food products and production systems
- 1994
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Ingår i: Trends in Food Science & Technology. - 0924-2244 .- 1879-3053 .- 0346-718X. ; 5:5, s. 134-138
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Tidskriftsartikel (refereegranskat)abstract
- In the late 1980s the demands for a more ecological life style and sustainability set off intense research for methods to analyse and assess the environmental impact of products and systems. The methodology crystallizing from this research is called life cycle assessment (LCA). This paper presents the concept, methodology, applications and present status of LCA. LCA as applied to food production systems is discussed in terms of needs, special demands on methodology, the studies that have been performed and ongoing activities. © 1994.
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| 6. |
- Borjesson, T., et al.
(författare)
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Volatile metabolites produced by six fungal species compared with other indicators of fungal growth on cereal grains
- 1992
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Ingår i: Applied and Environmental Microbiology. - Washington : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 58:8, s. 2599-2605
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Tidskriftsartikel (refereegranskat)abstract
- Six fungal species, Penicillium brevicompactum, P. glabrum, P. roqueforti, Aspergillus flavus, A. versicolor, and A. candidus, were inoculated on moistened and autoclaved wheat and oat grains. They were cultivated in glass vessels provided with an inlet and outlet for air. Air was passed through the vessels to collect volatile fungal metabolites on porous polymer adsorbents attached to the outlet. Samples were collected at two fungal growth stages. Adsorbed compounds were thermally desorbed, separated by gas chromatography, and identified by mass spectrometry. Differences in the production of volatile metabolites depended more on the fungal species than on the grain type. The fungal growth stage was not an important factor determining the composition of volatiles produced. 3-Methylfuran was produced in similar amounts regardless of the fungal species and substrate (oat versus wheat). The production of volatile metabolites was compared with the production of ergosterol and CO2 and the number of CFU. The production of volatile metabolites was more strongly correlated with accumulated CO2 production than with actual CO2 production and more strongly correlated with ergosterol contents of the grain than with numbers of CFU.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Nordström, Jan-Erik, et al.
(författare)
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The Rheology of Wood -Considerations of the Mechano-Sorptive Creep
- 1994
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Ingår i: Träfysik-kompendium. - Stockholm : KTH Royal Institute of Technology. ; , s. 1-11
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This review of previous investigations is limited to the most descriptive material perceived by the authors to the actual phenomenon called "mechano-sorptive creep in wood". A detailed explanation of the situation today is presented, focusing on the macroscale considerations, highlighting also the influence of microscaled components (morphology, chemistry) in wood, which may provide an important explanation of the phenomenon. A discussion is performed combined with major conclusions on the subject.
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