Annette Veberg Dahl

• Lee, Michael R.F.; Scott, Mark B; Veberg-Dahl, Annette; Evans, P; Theobald, Vince J. & Lundby, Frank [Vis alle 8 forfattere av denne artikkelen] (2013). Potential of Chlorophyll-Rich Feed Ingredients To Improve Detection of Fecal Contamination in the Abattoir. Journal of Food Protection. ISSN 0362-028X. 76(3), s. 516–522. doi: 10.4315/0362-028X.JFP-12-353. Vis sammendrag

  The use of fecal fluorescence to improve detection of contamination of carcasses in the abattoir was previously reported. However, incidents of false negatives can result when animals are offered diets that contain little chlorophyll (e.g., concentrate). Here, we investigated the potential of incorporating a high-chlorophyll-containing feed ingredient (concentrated alfalfa extract; CAE) into the diets of sheep and cattle to improve fecal fluorescence intensity. The sheep experiment evaluated the fecal fluorescence of animals from pasture, when fed a concentrate–barley straw diet and when the concentrate diet incorporated CAE (100 g of dry matter a day). Fecal chlorophyll and metabolite content was highest on the pasture-fed animals and increased significantly over the concentrate diet when CAE was included. Subsequently fluorescent intensity was increased from 15,000 to 36,000 arbitrary units for concentrate and CAE–concentrate diets, respectively, compared with 59,000 for the pasture-fed animals. The cattle experiment investigated the potential of CAE to improve fluorescence of feces from a concentrate diet as well as a silage diet at two levels of incorporation (75 and 150 g CAE/kg of dry matter intake). This study also determined the fluorescence of digesta and carcass contamination in the abattoir on a subset of carcasses. In agreement with the sheep study, CAE significantly improved fluorescence of feces and digesta when added to a concentrate diet, but had little effect on improving fecal fluorescence from the silage-fed animals. This was thought to be related to greater chlorophyll degradation in the rumen or/ and the dark nature of the silage feces acting as a quencher of emitted fluoresced light. Incorporating high-chlorophyll-containing plant ingredients into ruminant concentrate diets will improve detection of fecal contamination by reducing false-negative readings. However, they will have little effect on false-positive readings due to the range of wavelengths emitted by natural chlorophyll and its metabolites. Implications and potential solutions for this are discussed.

• Adler, Steffen Andreas; Dahl, Annette Veberg; Jensen, Søren Krogh; Thuen, Erling; Gustavsson, Anne-Maj & Steinshamn, Håvard (2013). Fatty acid composition,fat-soluble vitamin concentrations and oxidative stability in bovine milk produced on two pastures with different botanical composition. Livestock Science. ISSN 1871-1413. 154(1-3), s. 93–102. doi: 10.1016/j.livsci.2013.03.013. Fulltekst i vitenarkiv Vis sammendrag

  Previous research has shown that grazing pastures compared to feeding preserved forages has large impact on milk fatty acid (FA) composition, but differences between grazing red clover (Trifolium pratense L.) or white clover (Trifolium repens L.) are small, whereas the herbage proportions of dicotyledon botanical families is positively correlated with the milk-fat proportions of total polyunsaturated FA when grazing pastures in the Alps. The objective of the present study was to investigate the influence of botanically different pastures on bovine milk composition and milk susceptibility to oxidation. Two groups of 8 multiparous Norwegian Red dairy cows [mean (standard deviation); 599 (45.1)kg body weight, 73 (15.0)d in milk, 29.9 (2.90)kg milk/d at experiment start] grazed either a short-term pasture (SP) or a long-term pasture (LP). Both pastures were organically managed, meaning that no artificial fertilizers or herbicides were applied. The SP was representative for pastures, which are frequently, i.e. at least every third year, renewed by soil tillage and seeding, whereas LP was representative for pastures, which are less frequently renewed. The SP contained mainly meadow fescue (Festuca pratensis Huds.), timothy (Phleum pratense L.) and red clover and LP contained smooth meadow grass (Poa pratensis L.), white clover and a variety of unsown species. Sixteen cows were blocked according to milk yield, days in milk and sire, and randomly within block allocated to the 2 dietary treatments with a daily pasture allowance of 15–20kg dry matter per cow, supplemented with 3.0kg barley (Hordeum vulgare L.) concentrate. Milk was sampled during the last week of 3 experimental periods and analysed for FA composition by gas chromatography, concentrations of fat-soluble vitamins by high performance liquid chromatography, and oxidative stability in a light-exposure experiment by measuring the formation of hydroperoxides and by front-face fluorescence spectroscopy. Pasture type had no effect on milk yield, milk gross composition, and only minor effects on milk FA composition. Milk from SP had higher concentration of α-tocopherol than LP. The formation of hydroperoxides in milk was lower for SP than LP after 24h light exposure, but no differences were found after 48h. Front-face fluorescence spectroscopy revealed slightly higher formation of components in the area of 409–480nm wavelength for SP than LP, which may be related to milk-lipid oxidation. The experimental pastures differed mainly in herbage proportions of red clover and white clover and less in proportions of non-legume dicotyledons. This explains small differences in milk FA composition and milk susceptibility to oxidation.

• Intawiwat, Natthorn; Dahl, Annette Veberg; Pettersen, Marit Kvalvåg; Skaret, Josefine; Rukke, Elling-Olav & Wold, Jens petter (2011). Effect of different wavelength of light on the formation of photo-oxidation in Gouda-like cheese. International Dairy Journal. ISSN 0958-6946. 21(8), s. 531–539. doi: 10.1016/j.idairyj.2011.03.005.
• Lee, Michael R.F.; Theobald, Vince J.; Ougham, Helen J.; Dahl, Annette Veberg; Lundby, Frank & Scollan, Nigel D. [Vis alle 7 forfattere av denne artikkelen] (2010). Natural faecal fluorophores and the potential of chlorophyll based markers to optimise fluorescence as a real-time solution for the detection of faecal contamination on carcasses. Meat Science. ISSN 0309-1740. 86(4), s. 966–975. doi: 10.1016/j.meatsci.2010.08.002.
• Intawiwat, Natthorn; Pettersen, Marit Kvalvåg; Rukke, Elling-Olav; Meier, Markus; Vogt, Kjell gjermund & Dahl, Annette Veberg [Vis alle 9 forfattere av denne artikkelen] (2010). Effect of different colored filters on photooxidation in pasteurized milk. Journal of Dairy Science (JDS). ISSN 0022-0302. 93(4), s. 1372–1382. doi: 10.3168/jds.2009-2542. Vis sammendrag

  The effect of different colored filters and atmospheres on photooxidation and quality in milk was studied. Pasteurized bovine milk (3.9% fat) was packed in 2 different atmospheres (air and N-2) and exposed to light for 20 h at 4 degrees C under 8 transparent filters with different light transmission properties. The following transparent, noncolored, and colored filters based on polyethylene terephthalate (PET) were used: noncolored (PET), noncolored with 2 different UV-block regions, yellow, green, amber, orange, and red. Control samples were stored in darkness and in a carton. Sensory evaluation showed off flavors significantly increased in milk stored under all filters compared with the control samples. Variation in atmosphere resulted in significant differences in formation of rancid flavor in milk stored under different filters. Milk samples stored in N2 underwent the most sensory deterioration under orange and red filters, whereas milk samples stored in air were most deteriorated under noncolored filters. According to the oxidation compounds measured by gas chromatography, milk samples stored under noncolored and orange filters were highly oxidized, whereas red, green, and amber filters offered better protection against photooxidation. Fluorescence spectroscopy was used to examine the degradation of photosensitizers (riboflavin, protoporphyrin, and chlorophyllic compounds) in the milk samples. Degradation of protoporphyrin and chlorophyllic compounds in N-2 correlated well with sensory properties related to photooxidation (R-2 = 0.75-0.95). The study indicates that protoporphyrin and chlorophyllic compounds were effective photosensitizers in milk. To avoid photooxidation in milk, it is therefore important to protect it against light from the UV spectrum as well as light from the entire visible region.

• Larsen, Hanne; Tellefsen, Siri Geiner & Dahl, Annette Veberg (2009). Quality of Sour Cream Packaged in Cups with Different Light Barrier Properties Measured by Fluorescence Spectroscopy and Sensory Analysis. Journal of Food Science. ISSN 0022-1147. 74(8), s. S345–S350. doi: 10.1111/j.1750-3841.2009.01303.x. Vis sammendrag

  PRACTICAL APPLICATION: Dairy products such as sour cream will develop off-odor and taste faults ("sunlight taste") in a few hours if exposed to sufficient fluorescent lightning in the grocery stores. A light barrier can be incorporated in the packaging material to protect the dairy products from the light. Our experiment showed that the incorporation of a black pigment into 1 of the 3 plastic layers in the cup for packaging of sour cream protected the sour cream from degradation when exposed to light.

• Wold, Jens Petter; Dahl, Annette Veberg; Lundby, Frank; Nilsen, Asgeir Nikolai; Juzeniene, A & Moan, Johan Emilian (2009). Effect of Oxygen Concentration on Photo-oxidation and Photosensitizer Bleaching in Butter. Photochemistry and Photobiology. ISSN 0031-8655. 85(3), s. 669–676. doi: 10.1111/j.1751-1097.2008.00492.x.
• Dahl, Annette Veberg; Olsen, Elisabeth; Vogt, Gjermund; Mielnik, Maria B.; Nilsen, Asgeir & Wold, Jens-Petter (2006). Front face fluorescence spectroscopy - A rapid method to detect early lipid oxidation in freeze stored minced turkey meat. Journal of Food Science. ISSN 0022-1147. 71(4). Vis sammendrag

  The purpose of this study was to elucidate the ability of front face fluorescence to measure early lipid oxidation in minced turkey meat, and compare it to other methods for determination of oxidative status such as sensory analysis, dynamic headspace gas chromatography combined with a mass spectrometer (GC-MS), and thiobarbituric acid-reactive substances (TBARS) value. This comparison was performed on one batch of minced turkey meat. The meat was stored at -20 degrees C and -10 degrees C in vacuum or exposed to air. The results showed that fluorescence analysis is a sensitive, nondestructive method for measurement of early lipid oxidation and its rapidity and ease of use facilitates it as a practical screening method in research as well as food production. The level of specific marker compounds for lipid oxidation (for example, I-penten-3-ol) was highly correlated with the fluorescent data.

• Olsen, Elisabeth Fjærvoll; Veberg, Annette ; Vogt, Kjell Gjermund; Tomic, Oliver; Kirkhus, Bente & Ekeberg, Dag [Vis alle 7 forfattere av denne artikkelen] (2006). Analysis of early lipid oxidation in salmon patè with cod liver oil and antioxidants. Journal of Food Science. ISSN 0022-1147. 71(3), s. 284–292. doi: 10.1111/j.1365-2621.2006.tb15655.x.
• Olsen, Elisabeth; Vogt, Kjell Gjermund; Dahl, Annette Veberg; Ekeberg, Dag & Nilsson, Astrid (2005). Analysis of early lipid oxidation in smoked, comminuted, pork or poultry sausages with spices. Journal of Agricultural and Food Chemistry. ISSN 0021-8561. 53. doi: 10.1021/jf050886w. Vis sammendrag

  Dynamic headspace/gas chromatography-mass spectrometry (GC-MS), front-face fluorescence spectroscopy, and a gas-sensor array technique (electronic nose) have previously detected lipid oxidation in pork back fat or mechanically recovered poultry meat earlier than or at the same time as a sensory panel. The present study was focused on measurement of early lipid oxidation in a more complicated product (freeze-stored, smoked sausages with spices). During the storage time, formation of components contributing to rancid odor and flavor (e.g., hexanal and 1-penten-3-ol) could be monitored with dynamic headspace/GC-MS. The GC-MS data also showed a decrease in 2-furancarboxalclehyde, which could indicate loss of Maillard type components often associated with acidic or meat odor and flavor. The fluorescence spectra were difficult to interpret, probably due to the simultaneous influence from increasing levels of lipid oxidation products and loss of fluorescent Maillard or spice components. The gas-sensor array responses were dominated by signals from, e.g., spice and smoke compounds.

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• Gjellebæk, Camilla; Dahl, Annette Veberg; Del Busso, Lilliana Andrea; Edvardsen, Magdalena & Grøndahl, Vigdis Abrahamsen (2021). HiØ best på kjønnsbalanse - vil fortsatt holde stand på barrikadene. Fredriksstad Blad.
• Dahl, Annette Veberg (2021). Ønsker mer fysisk aktivitet og sosialt samvær i studentlivet. [Radio]. NRK-P1 Østfold Distriktsprogram .
• Dahl, Annette Veberg (2021). Ønsker mer fysisk aktivitet og sosialt samvær i studentlivet. [TV]. Distriktsnyheter Oslo og Viken.
• Omvik, Eirik; Dahl, Annette Veberg & Dursun, Kamil Mustafa (2019). Starter ny master. [Fagblad]. Energi Utdanning 2019.
• Waksvik, Guro & Dahl, Annette Veberg (2017). Aldri før har flere strømmet inn på bioingeniørstudiet. [Fagblad]. Bioingeniøren.
• Dahl, Annette Veberg (2015). Ingeniørstudenter viste frem prosjekter for næringslivet og publikum - ÅRETS STORE BEGIVENHET. [Avis]. Fredrikstad Blad.
• Dahl, Annette Veberg; Wold, Jens Petter; Moan, Johan Emilian & Lundby, Frank (2014). Hvorfor smaker melk vondt når den har blitt utsatt for lys?
• Adler, Steffen Andreas; Steinshamn, Håvard; Dahl, Annette Veberg; Thuen, Erling; Jensen, Søren Krogh & Hansen-Møller, Jens (2011). Effekt av surfôr fra kortvarig eng eller langvarig eng på kvalitet i kumelk. I Brodin, Janne Karin & Fog, Megumi Ohta (Red.), Husdyrforsøksmøtet 2011. Universitetet for miljø- og biovitenskap. ISSN 978-82-7479-024-7. s. 181–184.
• Adler, Steffen; Dahl, Annette Veberg; Steinshamn, Håvard; Vae, Anne Holter; Thuen, Erling & Garmo, Torstein H. [Vis alle 7 forfattere av denne artikkelen] (2009). Effekt av rødkløverbeite eller botanisk allsidig beite på kvalitetsegenskaper hos melk i økologisk drift. Vis sammendrag

  Et kontinuerlig beiteforsøk med 3 perioder à 3 uker ble gjennomført med 16 NRF-kyr i midtlaktasjonen. Målsetningen var å sammenligne melkequalitet når kyrne beitet rødkløvergras (RB) eller botanisk allsidig beite (AB). beitetype hadde ingen effekt på ytelse, melkas fettinnhold eller proteininnhold. Kyr som beitet RB hadde en høyere andel av fettsyrene C18:0 (22.41 vs. 9.96, P<0.05) og C18:1t11 (0.58 vs. 0.44 g/100g FAME, P<0.05) og lavere andel C16:0 (27.83 vs. 30.92, P<0.05) i melkefettet sammenlignet med kyr som beitet AB. Innholdet av alfatokoferol var høyere i melk fra RB enn AB (3.01 vs. 2.64 µg/ml, P<0.05). Den oksidative stabiliteten av melkas lipider ble bare i mindre grad påvirket av beitetype.

• Adler, Steffen; Dahl, Annette Veberg; Steinshamn, Håvard; Vae, Anne Holter; Thuen, Erling & Garmo, Torstein H. [Vis alle 7 forfattere av denne artikkelen] (2009). Effect of pasture botanical composition on milk quality in organic production, NJF Report. Nordic Association of Agricultural Scientists. Vis sammendrag

  A continuous grazing experiment with three measurement periods, 3 weeks each, was conducted with 16 Norwegian Red dairy cows in mid lactation to compare milk quality when grazing red clover-grass (R) or botanical diverse pasture (D). The cows were offered either R or D from the start of grazing season in mid May until beginning of September 2008. Milk yield was measured and milk samples were collected in the last week in each period (end of June, beginning of August and end of August). Pasture type had no effect on milk yield and milk content of fat or protein. Cows grazing R had higher proportion of the fatty acids C18:0 (22.41 vs. 9.96, P<0.05) and C18:1t11 (0.58 vs. 0.44 g/100g FAME, P<0.05) and lower proportion of C16:0 (27.83 vs. 30.92, P<0.05) in their milk fat than the cows grazing D. The milk content of ?-tocopherol was higher in milk from R than D (3.01 vs. 2.64 µg/ml, P<0.05). The oxidative stability of the milk lipids were only minor affected by pasture type.

• Larsen, Hanne & Dahl, Annette Veberg (2009). Light waves and food products in display cabinets. New Food. s. 67–69.

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