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- Undeland, Ingrid, 1968, et al.
(författare)
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Comparison between methods using low-toxicity solvents for the extraction of lipids from herring (Clupea harengus)
- 1998
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Ingår i: Food Chemistry. - 0308-8146 .- 1873-7072 .- 0346-718X. ; 61:3, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- Three alkane/alcohol/water-based lipid extraction systems were evaluated to determine which would be the best replacement for the frequently used chloroform/methanol/water system, nowadays known to be very toxic. All the methods were applied to samples of minced herring (Clupea harengus) differing in quality and composition. In addition to comparisons of total lipid yield, the extracted lipids were compared with respect to content of triglycerides, phospholipids, free fatty acids, ?-tocopherol, lipid hydroperoxides and conjugated dienes. The content of phospholipids was found to differ most between the lipids extracted by the four methods. Here, the chloroform/methanol/water system was the most efficient, followed by heptane/ethanol/water/sodium dodecyl sulphate (SDS) and then iso-propanol/hexane. However, by decreasing the level of SDS, the efficiency of the heptane/ethanol/water/SDS system in extracting phospholipids was increased to the same level as that of the chloroform/methanol/water system. This decrease in SDS also resulted in a higher recovery of free fatty acids. The lack of correlation between yields of phospholipids and yields of lipid oxidation products throughout this study was surprising because of the often-described susceptibility of phospholipids to oxidation.
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| 2. |
- Undeland, Ingrid, 1968, et al.
(författare)
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Lipid Oxidation in Minced Herring (Clupea harengus) during Frozen Storage. Effect of Washing and Precooking
- 1998
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Ingår i: Journal of Agricultural and Food Chemistry. - 0021-8561 .- 1520-5118. ; 46, s. 2319-2328
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Tidskriftsartikel (refereegranskat)abstract
- A 23 factorial experimental design was used to investigate the effect of washing in combination with precooking on the oxidative stability of lipids in minced herring (Clupea harengus) at −18 °C. The following variables were studied: washing (no, yes), cooking time (38, 54 min), and cooking temperature (55, 100 °C).The responses monitored were peroxide value (PV), absorbance at 234 nm (A234), absorbance at 268 nm (A268), and lipid soluble fluorescent products (FP). A partial least-squares regression analysis (PLS) revealed that the best lipid stability was obtained at minimum cooking time and at lower temperature. On the basis of compositional analyses and in vitro experiments, this finding was proposed to be due to heat inactivation of catalytic enzymes, without simultaneous activation, for example, of hemoproteins. Washing reduced these benefits from precooking by removal of pro-oxidative enzymes and also through a reduction in the amount of antioxidants as well as a relative increase in phospholipids and free fatty acids in the fat.
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| 3. |
- Sandberg, Dick, 1967-, et al.
(författare)
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The Concept of Value Activation : the PrimWood Method for Improved Properties.
- 1998
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Ingår i: Timber and Wood Composites for the Next Century.
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Konferensbidrag (refereegranskat)abstract
- Value Activation is an integrated R&D programme carried out for the last eight years at the Royal Institute of Technology, Wood Technology and Processing. The name Value Activation refers to the basic understanding ofwood, where at present there are properties that are not fully exploited, but with help of a new sawing pattern could be fully utilized. The basic idea lies at an industrial level producing radially sawn timber with good profitability and with a lesser and mostly a controllable moisture movement. In short it implies an activation of values of timber, that has not been exploited in ordinary industrial production to date. This paper gives one example how the basic ideas in the concept ofValue Activation have been implemented to the industry. A new manufacturing system, the Prim Wood Method, has been proposed in order to improve the utilization of wood. One basic idea within this method is a new sawing pattern called star-sawing, which produces timber with two different shapes, viz., timber with rectangular and triangular cross sections. This method facilitates an efficient production of radially sawn timber with vertical annual rings, and without pith and juvenile wood. The triangles produced in star-sawing are used for producing high quality, knot free panels with vertical annual rings, PrimWood Prism. In this process, the timber is finger-jointed to form knot-free lengths and glued together into a block. This block can then be divided according to thickness into boards with vertical annual rings. In star-sawing, a certain volume of clear pieces will be obtained which are relatively long, i.e. longer than 1 metre. It is not desirable to finger-joint these boards, but instead to manufacture PrimWood Prism without a finger-joint. The first full-scale industrial plants based on the Value Activation concept are now in production in nothern Sweden. At full capacity, the saw mill will produce around 18000 m3 of star-sawn pine a year and shift. The plant for Prim Wood Prism will produce around 5 000 m3 a year and shift. The company is expect to generate two to three times the usual value from each log.
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| 7. |
- Andersson, Annika, et al.
(författare)
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The adhesion of Bacillus cereus spores to epithelial cells might be an additional virulence mechanism
- 1998
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Ingår i: International Journal of Food Microbiology. - 0168-1605 .- 1879-3460. ; 39:1-2, s. 93-9
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Tidskriftsartikel (refereegranskat)abstract
- Four out of ten Bacillus cereus strains produced spores able to adhere to monolayers of Caco-2 cells (human epithelial cells). One of these strains has been involved in an outbreak of food poisoning where the symptoms were more severe and persisted for longer than a normal B. cereus food poisoning. The hydrophobicity of the spores is a contributing factor for the adhesion to occur. The spores are able to germinate in an environment similar to that of the small intestine and then the vegetative cells can produce the enterotoxin directly at the target place. A concentrated and active form of the enterotoxin will be taken up by the epithelial cells in the small intestine. Spore adhesion could be an important virulence factor for some B. cereus strains.
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| 8. |
- Andersson, Karin, et al.
(författare)
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Screening life cycle assessment (LCA) of tomato ketchup : A case study
- 1998
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Ingår i: Journal of Cleaner Production. - 0959-6526 .- 1879-1786. ; 6:3-4, s. 277-88
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Tidskriftsartikel (refereegranskat)abstract
- A screening life cycle assessment (LCA) of tomato ketchup has been carried out. The purpose was to identify 'hot-spots', that is parts of the life-cycle that are important to the total environmental impact. The system investigated includes agricultural production, industrial refining, packaging, transportation, consumption and waste management. Energy use and emissions were quantified and some of the potential environmental effects assessed. Packaging and food processing were found to be hot-spots for many, but not all, of the impact categories investigated. For primary energy use, the storage time in a refrigerator (household phase) was found to be a critical parameter. © 1998 Elsevier Science Ltd. All rights reserved.
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| 9. |
- Andersson, Karin, et al.
(författare)
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The feasibility of including sustainability in LCA for product development
- 1998
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Ingår i: Journal of Cleaner Production. - 0959-6526 .- 1879-1786. ; 6:3-4, s. 289-98
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Tidskriftsartikel (refereegranskat)abstract
- The feasibility of combining the concept of sustainability principles and the methodology of Life Cycle Assessment (LCA) is examined. The goal is to achieve an operational tool that incorporates sustainability in product development and strategic planning. While the method outlined has the structure of LCA, it emphasises aspects and parameters often omitted from traditional LCA. The analysis and results can be either qualitative or semi-quantitative. Although a qualitative analysis is less time consuming, it can still highlight the important issues. Qualitative information, which is easily lost in a quantitative analysis, can be emphasised. One of the conclusions is that the method is well suited for screening analysis. © 1998 Elsevier Science Ltd. All rights reserved.
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| 10. |
- Carlsson, Peter, et al.
(författare)
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Optimization, a tool with which to create an effective drying schedule
- 1998
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Ingår i: Holzforschung. - : Walter de Gruyter. - 0018-3830 .- 1437-434X. ; 52:5, s. 530-540
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Tidskriftsartikel (refereegranskat)abstract
- A method for defining effective schedules for kiln drying of wood is presented. The method is designed in such a way that it proposes an optimized variation of temperature and humidity which yields the minimum total drying time, with the condition that the moisture content and the deformation not exceed specified limits after the drying and that the stress not exceeds a specified level at any time during the drying process in order to avoid crack development. To demonstrate the capability of the optimization method numerical results are presented. It should be noted that ill this first approach, drying starts from moisture content corresponding to the fibre-saturation point, i.e. approximate to 30%).
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