Sofia Trattner

1H NMR-based metabolomics studies on the effect of sesamin in Atlantic salmon (Salmo salar)

A (1)H NMR-based metabolomics approach was used to explore the impact of dietary sesamin on the liver and white muscle metabolic profile of Atlantic salmon (Salmo salar). Fish were fed diets containing different n-6/n-3 fatty acid ratios (V0.5 or V1) and sesamin contents [without (S0), low (SL) 1.16 g/kg feed, and high (SH) 5.8 g/kg feed] for 4 months. Liver and white muscle extracts of aqueous polar and chloroform lipid phases were collected. Multivariate data analyses (PCA and OPLS-DA) of liver chloroform phase showed that high levels of sesamin affected the metabolic profile impartially of the n-6/n-3 ratio. In the aqueous phase, the metabolome of liver and white muscle were affected in fish fed an n-6/n-3 ratio of 1.0 and 0.5, respectively. With high inclusion of sesamin, the levels of several metabolites (e.g. glucose, glycogen, leucine, valine, creatine, carnitine, lactate, nucleosides) were increased. These metabolites are mainly associated with energy metabolism, suggesting that high sesamin inclusion affects liver and white muscle metabolism in fish. This is consistent with lower body weights found in fish fed high sesamin content.

Fatty acid composition of Swedish bakery products, with emphasis on trans-fatty acids

Trans-fatty acids (TFA) have been associated with increased risk of coronary heart disease, by affecting blood lipids and inflammation factors. Current nutrition recommendations emphasise a limitation of dietary TFA intake. The aim of this study was to investigate fatty acid composition in sweet bakery products, with emphasis on TFA, on the Swedish market and compare fatty acid composition over time. Products were sampled in 2001, 2006 and 2007 and analysed for fatty acid composition by using GC. Mean TFA levels were 0.7% in 2007 and 5.9% in 2001 of total fatty acids. In 1995-97, mean TFA level was 14.3%. In 2007, 3 of 41 products had TFA levels above 2% of total fatty acids. TFA content had decreased in this product category, while the proportion of saturated (SFA) and polyunsaturated (PUFA) fatty acids had increased, mostly through increased levels of 16:0 and 18:2 n-6, respectively. The total fat content remained largely unchanged.

Effect of processing on amine formation and the lipid profile of cod (Gadus morhua) roe.

The processing of fish roe leads to changes in its chemical composition, the extent of which depends on the techniques and additives employed. This study aimed to investigate the effects of ripening temperature and the use of sodium benzoate and citric acid on the quality of ripened cod roe, with respect to the contents of volatile base nitrogen (VBN), trimethylamine (TMA), biogenic amines (BA) and on the lipid composition. In comparison with fresh roes, ripened roes presented higher contents of VBN, TMA, BA and the proportion of free fatty acids regardless of the temperature and additives used during the ripening process. The greatest increases were observed in the samples ripened at 17°C without additives, in which histamine was detected at 8.8mg/100g. A low ripening temperature was the main factor responsible for minimising changes in the cod roe composition. The addition of sodium benzoate as a preservative or citric acid to decrease the pH value had a significant effect in maintaining the quality of the cod roes, mainly at high ripening temperature.

Feeding steam-pelleted rapeseed affects expression of genes involved in hepatic lipid metabolism and fatty acid composition of chicken meat

&NA; This study investigated the dietary effect of steam‐pelleted rapeseed (RS) diets with different inclusion levels on the fatty acid composition of chicken meat and the expression of lipid metabolism‐related genes in the liver. Experimental diets included 6 different wheat‐soybean meal based diets either in nonpelleted or steam‐pelleted form supplemented with 80, 160, and 240 g RS/kg feed and one nonpelleted wheat‐soybean meal based diet without RS supplementation as the control. These diets were fed to newly hatched broiler chickens (Ross 308) for 34 days. Compared to the control diet, steam‐pelleted diets containing 160 or 240 g/kg RS significantly increased the content of omega‐3 long chain polyunsaturated fatty acids (n‐3 LC‐PUFA) in the breast and drumstick, while their meat yields were not affected. Moreover, the mRNA levels of fatty acid desaturase 1 (FADS1) and acyl‐coenzyme A oxidase 1 (ACOX1) in their livers increased. Therefore, steam‐pelleted diets with 160 or 240 g/kg RS can be used to increase the n‐3 LC‐PUFA content in chicken meat without compromising meat yield.

Stimulatory effect of sesamin on hepatic cytochrome P450 activities in Atlantic salmon (Salmo salar L.) is not directly associated with expression of genes related to xenobiotic metabolism.

Abstract 1. This study examined hepatic cytochrome P450 (CYP450) response to dietary sesamin in combination with different n-6/n-3 fatty acid ratios in fish diet. Over a period of 4 months, fish were fed seven different experimental diets an n-6/n-3 FA ratio of either 0.5 or 1.0 in combination with two sesamin levels: low sesamin = 1.16 g/kg feed and high sesamin = 5.8 g/kg feed. Control diets did not contain sesamin. 2. The CYP450-associated activities of ethoxyresorufin O-deethylase (EROD), 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylation (BFCOD), pentoxyresorufin O-depentylase (PROD), coumarin hydroxylase (COH), methoxyresorufin O-deethylase (MROD) and p-nitrophenol hydroxylase (PNPH) were significantly induced by dietary sesamin in a dose-related manner. 3. Expressions of the genes CYP1A1, CYP1A3, CYP3A, AhR1α, AhR2β, AhR2δ and PXR involved in the regulation of CYP450 activities, was not the primary source of this induction.