Tove Devold - Academia.edu (original) (raw)

Papers by Tove Devold

The impact of viscosity on emulsion stability at pH 2 using 1% (w/w) rapeseed oil (RSO) with 0.2 ... more The impact of viscosity on emulsion stability at pH 2 using 1% (w/w) rapeseed oil (RSO) with 0.2 and 2% (w/w) whey protein concentrate (WPC) and 0.1 % (w/w) chitosan (CH) during 1 and 16 days of storage was investigated. The droplet size values obtained by image analysis were correlated with the viscosity values. All the emulsions behaved like non-Newtonian fluids, having shearthickening characteristics, as the flow behaviour index values were larger than 1. A reduction in emulsion droplet size from 2.24 (2% WPC) to 0.95 μm (2% WPC, 0.1% CH) was observed when chitosan was added to the emulsions containing WPC (day 1). Addition of chitosan to WPC-emulsions caused about 20% relative increase in the viscosity. An increase in viscosity with a decrease in droplet size was observed. During the storage for up to 16 days, no water separation of WPCchitosan emulsions was noticed, indicating that the stability of these emulsions was maintained at 4 oC. The stability observations were related ...

The effect of type of emulsifier, 2 w/w% whey protein concentrate (WPC) or 2 w/w% WPC and 0.1 w/w... more The effect of type of emulsifier, 2 w/w% whey protein concentrate (WPC) or 2 w/w% WPC and 0.1 w/w% chitosan (CH) on the rheological changes and droplet size distribution during the ex vivo digestion of oil in water emulsions (pH 2) containing 1 w/w% rapeseed oil (RSO) were investigated. The procedure was used to mimic the human gastro duodenal digestion in two steps, gastric phase at pH 2 for 30 min followed by the duodenal phase at pH 7 for 60 min. With regard to viscosity, the emulsion, either WPC or WPC-CH showed an increase from gastric phase to duodenal phase (p<0.001) and then it was stable until the end of digestion. The viscosity of WPC-CH emulsions during the whole digestion (with/without added HGJ/HDJ) process was higher than the respective WPC emulsions. At pH 7 (duodenal juice addition), the droplet diameters stabilized by WPC emulsion showed a bimodal distribution with droplet sizes in the range of 0.05-1.7 µm and 200-500 µm. A significant change (p<0.01) in the o...

Goat milk contributes significantly to human nutrition and has been used in functional food appli... more Goat milk contributes significantly to human nutrition and has been used in functional food applications in many parts of the world. Among the components in milk, lactoferrin (Lf) is a multifunctional glycoprotein that plays an important role in immune regulation and defence mechanisms against bacteria, fungi and viruses. The biological activity may be affected by thermal treatment during industrial processes. The production and content of Lf in milk from different species seems to vary a lot. This study aims to compare the thermal stability and structural differences in bovine (Blf) and caprine Lf (Clf) under conditions such as pH and iron content. The X-ray crystallography investigation has shown the presence of alpha helical and beta sheet contents to different degrees in Lf among both species which upholds stability to the molecule. In addition, the iron saturation was found to be important in Lf structure and stability. In the present investigation an attempt has been made to a...

Small Ruminant Research, 2014

Journal of Dairy Science, 2013

Journal of Dairy Science, 2010

Food chemistry, Jan 15, 2014

In this study, we analysed the impact of carboxymethylcellulose (CMC) on lipid digestion and phys... more In this study, we analysed the impact of carboxymethylcellulose (CMC) on lipid digestion and physicochemical properties of whey proteins (WP)-stabilised emulsions during in vitro digestion with either artificial or human gastrointestinal juices. The emulsions were made by adsorbing WP on the fat droplets and subsequently adding CMC, which does not interact with the adsorbed proteins. The limited hydrolysis of lipids and their higher physical stability was recorded for WP-stabilised emulsions in the presence of CMC under simulated gastrointestinal conditions. The possible mechanism by which CMC lowers the digestion of WP-stabilised emulsions is related to the limited interaction of fat droplets with gastrointestinal fluids due to the extended thickening network formed by CMC in the continuous phase. The digestion of WP- and CMC-stabilised emulsions in the in vitro model with human gastric fluids led to greater lipid hydrolysis, although the enzymatic activity in both in vitro models ...

British Journal of Nutrition, 2010

Small Ruminant Research, 2014

Nutrition Research, 2012

Many infant formulas are enriched with lactoferrin (Lf) because of its claimed beneficial effects... more Many infant formulas are enriched with lactoferrin (Lf) because of its claimed beneficial effects on health. Native bovine Lf (bLf) is known to inhibit in vitro replication of human enteroviruses, a group of pathogenic viruses that replicate in the gut as their primary infection site. On the basis of a model digestion and human gastrointestinal enzymes, we hypothesized that bLf could retain its antiviral properties against enterovirus in the gastrointestinal tract, either as an intact protein or through bioactive peptide fragments released by digestive enzymes. To test our hypothesis, bLf was digested with human gastric juice and duodenal juice in a 2-step in vitro digestion model. Two gastric pH levels and reduction conditions were used to simulate physiological conditions in adults and infants. The antiviral activity of native bLf and of the digested fractions was studied on echovirus 5 in vitro, using various assay conditions, addressing several mechanisms for replication inhibition. Both native and digested bLf fractions revealed a significant inhibitory effect, when added before or simultaneously with the virus onto the cells. Furthermore, a significant stronger sustained antiviral effect was observed when bLf was fully digested in the gastric phase with fast pH reduction to 2.5, compared with native bLf, suggesting the release of antiviral peptides from bLf during the human digestion process. In conclusion, this study demonstrates that bLf may have a role in the prevention of human gastrointestinal virus infection under physiological conditions and that food containing bLf may protect against infection in vivo.

International Dairy Journal, 2000

International Dairy Journal, 2006

... recently been an increased attention on cows' milk allergy, particularly among infants (... more ... recently been an increased attention on cows' milk allergy, particularly among infants (Paupe, Paty, de Blic, & Scheinmann, 2001; Sampson, 2004). ... Bovine milk has nine different genetic variants, however, type B is dominant in Europe (Bech & Kristiansen, 1990; Lien et al., 1999 ...

International Dairy Journal, 1999

The influence of milk protein genetic variants on the quality, composition and technological prop... more The influence of milk protein genetic variants on the quality, composition and technological properties of milks from Norwegian Red cattle has been studied. Results are reported for a small sample of 55 cows.