| 1. |
- Undeland, Ingrid, 1968, et al.
(författare)
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Lipid oxidation in fillets of herring (Clupea harengus) during frozen storage. Influence of pre-freezing storage.
- 1999
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 47:5, s. 2075-2081
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Tidskriftsartikel (refereegranskat)abstract
- Fillets of herring (Clupea harengus) were kept on ice for 0, 3, 6, and 9 days prior to storage at −18 °C for 0, 21, 42, 63, and 84 days. At each storage point, peroxide value (PV), absorbance at 268 nm (A268), fluorescent products (FP), α-tocopherol, glutathione peroxidase (GSH-px) activity, and ascorbic acid were measured. As shown by regression analyses, samples held for 6 days on ice formed oxidation products at the highest rate during frozen storage, followed by, for PV and FP, the 9-day samples. These data indicate that severe changes that negatively affect the oxidation process took place in the herring muscle between 3 and 6 days after catch. Both the initial antioxidant levels and the rate of antioxidant loss at −18 °C decreased with increased prefreezing holding time, the latter being most obvious for GSH-px activity and ascorbic acid. α-Tocopherol showed the largest losses and had disappeared entirely from the 6- and 9-day samples at the end of the frozen storage. Partial least-squares regression analysis of the data showed that ice storage had a greater effect than frozen storage on changes in PV, A268, FP, α-tocopherol, and ascorbic acid. For GSH-px activity, frozen storage had the greatest effect.
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| 2. |
- Undeland, Ingrid, 1968, et al.
(författare)
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Lipid Oxidation in Fillets of Herring (Clupea harengus) during Ice Storage
- 1999
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 47:2, s. 524-532
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Tidskriftsartikel (refereegranskat)abstract
- The influence of ice storage on lipid oxidation, odor, antioxidants, water-soluble catalysts, and microorganisms was investigated in fillets of herring (Clupea harengus) during 15 days. Based on linear regression analyses of the data, significant rises (p ≤ 0.05) in lipid oxidation products were seen after 2−3 days and in “rancid” odor after 2.5 days. Peroxide value (PV), fluorescent product (FP), and ascorbic acid analyses were the chemical measures most strongly correlated to “rancid” odor (r = 0.97). Antioxidants decreased in the following order: α-tocopherol > ascorbic acid > glutathione peroxidase (GSH-px); however, GSH-px correlated best to the development of lipid oxidation products (rmean = −0.96). The activity of aqueous pro-oxidants, which were enzymatic in nature to a great extent, had decreased by 75% at day 15. No significant increase in total bacteria was seen until after 7 days. There were major local differences in both composition and stability throughout the fillet. Oxidation proceeded most rapidly in the tissue right under the skin, probably explained by its high initial pro-oxidative activity.
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| 3. |
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| 4. |
- Björklund, Anna, et al.
(författare)
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Planning Biodegradable Waste Management in Stockholm
- 1999
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Ingår i: Journal of Industrial Ecology. - 1088-1980 .- 1530-9290. ; 3:4, s. 43-58
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Tidskriftsartikel (refereegranskat)abstract
- The environmental impact of the management of biodegradable waste in Stockholm, based mainly on incineration and landfilling, was compared to systems with significant nutrient recycling; large-scale composting, anaerobic digestion, and separate collection and utilization of urine. The systems' emissions, residual products, energy turnover, and resource consumption were evaluated from a life-cycle perspective, using a computerized model, ORWARE (ORganic WAste REsearch model). Transportation was of relatively low importance to overall environmental impact, even at high rates of nutrient recycling. This is remarkable considering the geographical setting of Stockholm, with high population density and little nearby farmland. Ancillary systems, such as generation of electricity and district heating, were crucial for the overall outcome. Increased recycling of nutrients in solid biodegradable waste in Stockholm can reduce net environmental impact, whereas separation of human urine to be spread as fertilizer cannot yet be introduced without increased acidification. Increased nutrient recycling from solid biodegradable waste inevitably increases spreading of metals on arable land. Urine is by far the least contaminated residual product. Spreading of all other residuals would be limited by their metal content.
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| 5. |
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| 6. |
- Petersson, Stina, et al.
(författare)
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Growth of Penicillium roqueforti, P-carneum, and P-paneum during malfunctioning airtight storage of high-moisture grain cultivars
- 1999
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Ingår i: Postharvest biology and technology. - : Elsevier. - 0925-5214 .- 1873-2356. ; 17:1, s. 47-54
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Tidskriftsartikel (refereegranskat)abstract
- Penicillium roqueforti is an important spoilage fungus in high-moisture grain stored under airtight conditions where a malfunctioning storage system allows air leakage. It has recently been proposed that P. roqueforti be divided into three different species: P. roqueforti, P. carneum, and P. paneum (Boysen, M., Skouboe, P., Frisvad, J., Rossen, L., 1996. Reclassification of the Penicillium roqueforti group into three species on the basis of molecular genetic and biochemical profiles. Microbiology 142, 541-549). Differences in susceptibility to infection with the three mold species among winter wheat, spring wheat, rye, and barley during airtight storage of high-moisture grain were evaluated using a variety of grain cultivars. To simulate air leakage into such a storage system, grain (0.96 water activity) was inoculated, packed in glass tubes with a restricted air supply and incubated at 25 degrees C for 14 days. Molds and yeasts were quantified as colony forming units (CFU) on selective media. Generally, there was no difference in infection ability between P. roqueforti, P. carneum and P. paneum. All of them reached about 10(6) CFU/g in barley and winter wheat. However, rye appeared to be resistant to infection. A comparison of different barley and spring wheat cultivars revealed that P. roqueforti, P. carneum and P. paneum grew less vigorously on the malt cultivars Maud and Mentor and the spring wheat cv. Dragon than on other cultivars. In addition, batch-related differences in resistance to mold growth were found for spring wheat cv. Dragon.
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| 7. |
- Petersson, Stina, et al.
(författare)
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Pichia anomala as a biocontrol agent during storage of high-moisture feed grain under airtight conditions
- 1999
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Ingår i: Postharvest biology and technology. - : Elsevier. - 0925-5214 .- 1873-2356. ; 15:2, s. 175-184
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Tidskriftsartikel (refereegranskat)abstract
- Pichia anomala is antagonistic against a range of spoilage molds in vitro as well as against Penicillium roqueforti in high-moisture wheat during malfunctioning airtight storage in laboratory experiments. The use of Pichia anomala to improve the postharvest control of Penicillium roqueforti during airtight storage of feed grain was evaluated in outdoor silos. Inoculated and control winter wheat (cultivar Kosack) in 160-kg portions were stored at a water activity of 0.93 for 12 months in silos that were opened twice a week. During the first 2 months, inoculated Pichia anomala increased to about 10(7) colony-forming units (CFU)/g, while naturally occurring Pichia anomala in the treatments without inoculated yeast increased from 10(4) to 10(6) CFU/g. During the same period, CO2 concentrations increased to almost 70% and stabilized at 50-60%. During the coldest period, O-2 concentrations of <1% could be detected between samplings, whereas during the rest of the storage detectable O-2 levels were only found immediately after sampling. There were no clear differences in CO2 or O-2 levels between treatments. The inoculated Penicillium roqueforti did not grow during the storage period, probably owing to high numbers of Pichia anomala in combination with the high CO2 and low O-2 concentrations in the silos. In laboratory experiments, it was found that Pichia anomala survived long-term storage in airtight sealed test tubes better at 15 degrees C than at - 20 degrees C. The aerobic stability of moist wheat after 10 and 12 months of silo storage was clearly enhanced by an initial inoculation with Pichia anomala.
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| 8. |
- Andersson, Karin, et al.
(författare)
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Life cycle assessment of bread produced on different scales
- 1999
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Ingår i: The International Journal of Life Cycle Assessment. - 0948-3349 .- 1614-7502 .- 0346-718X. ; 4:1, s. 25-40
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Tidskriftsartikel (refereegranskat)abstract
- A case study of white bread has been carried out with the purpose of comparing different scales of production and their potential environmental effects. The scales compared are: home baking, a local bakery and two industrial bakeries with distribution areas of different sizes. Data from the three bakeries and their suppliers have been collected. The systems investigated include agricultural production, milling, baking, packaging, transportation, consumption and waste management. Energy use and emissions have been quantified and the potential contributions to global warming, acidification, eutrophication and photo-oxidant formation have been assessed. The large industrial bakery uses more primary energy and contributes more to global warming, acidification and eutrophication than the other three systems. The home baking system shows a relatively high energy requirement; otherwise, the differences between home baking, the local bakery and the small industrial bakery are too small to be significant.
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| 9. |
- Göranzon, Helen
(författare)
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Energi och metabolism
- 1999
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Ingår i: Näringslära för högskolan. - : Liber AB Stockholm. ; , s. 102-117
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 10. |
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