| 1. |
- Al-Souti, Ahmed, et al.
(författare)
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The effects of fish oil-enriched diets on growth, feed conversion and fatty acid content of red hybrid tilapia, Oreochromis sp.
- 2012
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 133:3, s. 723-727
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Tidskriftsartikel (refereegranskat)abstract
- Juvenile, red hybrid tilapia were fed diets containing cod liver oil (0%, 4%, 8%, 12% of total diet) substituted against corn oil. After 10 weeks, no significant differences between treatments were seen in weight gain, specific growth rate, feed conversion ratio, whole body or dorsal muscle (fillet) proximate composition. Gas chromatography revealed significant differences in the total n-3 content and fatty acid profiles of dorsal muscle. The total n-3 content of dorsal muscle increased from 7.6% to 18.6%, total n-6 content fell from 37.5% to 12.9% and docosahexanaenoic acid increased from 5.8-16.1% of total fatty acids, in fish fed 0% and 12% fish oil, respectively. The retention of eicosapentaenoic acid was low in all dietary groups, possibly indicating selective use as a substrate for β-oxidation. The results demonstrate the potential to enhance the total n-3 fatty acids and docosahexaenoic acid in tilapia fillets by increasing dietary fish oil. © 2012 Elsevier Ltd. All rights reserved.
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| 2. |
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| 3. |
- Andersson, J. M., et al.
(författare)
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Pressurised hot water extraction with on-line particle formation by supercritical fluid technology
- 2012
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 134:4, s. 1724-1731
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Tidskriftsartikel (refereegranskat)abstract
- In this work, an on-line process for pressurised hot water extraction (PHWE) of antioxidants from plants as well as drying of the extract in one step by particle formation based on the use of supercritical carbon dioxide (SC-CO2) has been developed. This process has been called WEPO (R), water extraction and particle formation on-line. With this process, dried extracts from onion with the same composition of quercetin derivatives as non-dried extracts have been obtained as a fine powder with spherical particles from 250 nm to 4 mu m in diameter. The major compounds present in the extract were quercetin-3,4'-diglucoside, quercetin-4'-glucoside and quercetin. An auxiliary inert gas (hot N-2) was used to enhance the drying process. Parameters such as temperature (120 degrees C), SC-CO2 and N-2 pressures (80 and 12.5 bar, respectively) and flow rate of SC-CO2 (10 ml/min), have been settled by trial-and-error in order to achieve a fine and constant spray formation. Water content, size and morphology, antioxidant capacity and quercetin content of the particles were studied to evaluate the efficiency of the WEPO process. Results were compared with the ones from extracts obtained by continuous flow PHWE followed by freeze-drying. Results showed that both processes gave similar results in terms of antioxidant capacity, concentration of quercetin derivatives and water content, while only WEPO was able to produce defined spherical particles smaller than 4 mu m. (C) 2012 Elsevier Ltd. All rights reserved.
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| 4. |
- Andersson, Staffan, et al.
(författare)
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Carotenoid content and composition in rose hips (Rosa spp.) during ripening, determination of suitable maturity marker and implications for health promoting food products
- 2011
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 128, s. 689-696
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Tidskriftsartikel (refereegranskat)abstract
- Carotenoids are important antioxidants and valuable bioactive compounds contributing to the health benefits of different foods, and rose hips are known for high bioactive content. This study investigated the content of carotenoids and chlorophylls in hips from four rose species during the ripening period. Carotenoid content varied greatly between harvesting times, although species and year, and interactions between factors, also played an important role. Some carotenoids were identified only in hips of specific rose species. Some of the investigated compounds decreased (chlorophyll a) or increased (lycopene) consistently over the ripening period and could therefore be useful as maturity markers. An optimal content of total or specific carotenoids, e.g. for food products containing rose hips, might be obtained by proper choice of harvesting time and rose species. (C) 2011 Elsevier Ltd. All rights reserved.
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| 5. |
- Antiochia, Riccarda, et al.
(författare)
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Rapid and direct determination of fructose in food: A new osmium-polymer mediated biosensor
- 2013
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 140:4, s. 742-747
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the development and performance of a new rapid amperometric biosensor for fructose monitoring in food analysis. The biosensor is based on the activity of fructose dehydrogenase (FDH) immobilised into a carbon nanotube paste electrode according to two different procedures. The direct wiring of the FDH in a highly original osmium-polymer hydrogel was found to offer a better enzyme entrapment compared to the immobilisation of the enzyme in an albumin hydrogel. The optimised biosensor required only 5 U of FDH and kept the 80% of its initial sensitivity after 4 months. During this time, the biosensor showed a detection limit for fructose of I mu M, a large linear range between 0.1 and 5 mM, a high sensitivity (1.95 mu A cm(-2) mM), good reproducibility (RSD = 2.1%) and a fast response time (4 s). Finally, the biosensor was applied for specific determination of fructose in honey, fruit juices, soft and energy drinks. The results indicated a very good agreement with those obtained with a commercial reference kit. No significant interference was observed with the proposed biosensor. (C) 2012 Elsevier Ltd. All rights reserved.
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| 6. |
- Bankefors, Johan, et al.
(författare)
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A comparison of the metabolic profile on intact tissue and extracts of muscle and liver of juvenile Atlantic salmon (Salmo salar L.) - Application to a short feeding study
- 2011
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 129, s. 1397-1405
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Tidskriftsartikel (refereegranskat)abstract
- The metabolite profiles from muscles and livers of Atlantic salmon were investigated using high resolution nuclear magnetic resonance (HR-NMR) spectroscopy of aqueous extracts and magic angle spinning (MAS) NMR spectroscopy of intact tissues. Comparison of the data showed that most small metabolites present in the aqueous extracts were also identified in the Carr-Purcell-Meiboom-Gill (CPMG) MAS NMR spectra of the intact tissues. Not only the total omega-3 fatty acid content, but also the EPA and DHA content, in the muscle and liver tissues could be calculated directly from the diffusion-edited MAS NMR spectra without the need for lipophilic extraction. The effect of replacing a normal fish meal during a period of 3 months with a diet containing 20% zygomycete was also investigated by multivariate analysis of the NMR spectra. Principal component analysis (PCA) was used to study the small metabolites distribution in the aqueous extracts of liver and muscles, and revealed that the feed containing zygomycete could have an influence on the metabolites profiles of juvenile Atlantic salmon. (C) 2011 Elsevier Ltd. All rights reserved.
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| 7. |
- Bianchi, F., et al.
(författare)
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Characterisation of the volatile profile of orange juice contaminated with Alicyclobacillus acidoterrestris
- 2010
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 123:3, s. 653-658
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Tidskriftsartikel (refereegranskat)abstract
- A rapid and reliable analytical method, based on the characterisation of the volatile profile by dynamic headspace extraction followed by gas chromatography mass-spectrometry, was developed in order to early detect Alicyclobacillus acidoterrestris spoilage in orange juice. Gas chromatographic peak areas were submitted to multivariate statistical analysis (principal component and linear discriminant analysis) in order to visualise clusters within samples and to detect the volatile compounds able to differentiate contaminated from not-contaminated samples. Significant differences in the volatile profile of the analysed samples were found, assessing the reliability of the proposed method to detect the A. acidoterrestris contamination in orange juice.Neither guaiacol nor 2,6-dibromophenol, usually regarded as A. acidoterrestris contamination markers, were detected in the analysed samples.
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| 8. |
- Broberg, Anders, et al.
(författare)
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Content of antioxidant hydroquinones substituted by beta-1,6-linked oligosaccharides in wheat milled fractions, flours and breads
- 2010
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 121, s. 645-652
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to quantify seven antioxidant hydroquinones, substituted by beta-1,6-linked oligosaccharides, in wheat-based food products by HPLC. These novel compounds were discovered and characterised in our previous study. All seven compounds were quantified in wheat germ and bran. The most abundant compound, 4-hydroxy-3-methoxyphenyl beta-D-glucopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-(1 -> 6)-beta-D-glucopyranoside, was present at 6.3 g/kg in germ and 0.7 g/kg in bran. In whole-wheat grains, as well as in several kinds of wheat flour and wheat bread, these antioxidants were present at much lower concentrations; only two of them could be quantified. None of these compounds were detected in low-protein flour mixture. Their total content in analysed wheat products decreased in the following order: germ > bran > whole grains similar to whole grain flours > refined flours > refined bread >> low-protein flour mixture. It correlated well with the antioxidant capacity of water-ethanol extracts of these products determined by Trolox equivalent antioxidant capacity (TEAC) assay (r(2) = 0.984). The contribution of the analysed compounds to the total antioxidant capacity of wheat germ extract was 52%, whereas the contribution of the most abundant compound was 38%. (C) 2010 Elsevier Ltd. All rights reserved.
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| 9. |
- Domingo, Jose L., et al.
(författare)
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Human dietary exposure to perfluoroalkyl substances in Catalonia, Spain : temporal trend
- 2012
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Ingår i: Food Chemistry. - : Elsevier. - 0308-8146 .- 1873-7072. ; 135:3, s. 1575-1582
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we assessed the levels of 18 perfluoroalkyl substances (PFASs) in the most widely consumed foodstuffs in Catalonia, Spain, as well as the total dietary intake of these compounds. Forty food items were analysed. Only perfluoropentanoic acid (PFPeA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctanoicdecanoic acid (PFOcDA) were not detected in any sample. Perfluorooctane sulfonate (PFOS) was the compound found in the highest number of samples (33 out of 80), followed by perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA) and perfluorodecane sulfonic acid (PFDS). Fish and shellfish was the food group in which more PFASs were detected and where the highest PFAS concentrations were found. The highest dietary intakes corresponded to children, followed by male seniors, with values of 1787 and 1466 ng/day, respectively. For any of the age/gender groups of the population, the Tolerable Daily Intakes (TDIs) recommended by the EFSA were not exceeded. In general terms, PFAS levels found in the current study are lower than the concentrations recently reported in other countries.
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| 10. |
- Emmertz, Andrea
(författare)
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Mineral analysis of mono-floral New Zealand honey
- 2011
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 128, s. 236-240
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Tidskriftsartikel (refereegranskat)abstract
- The levels of 18 different minerals in ten locally produced mono-floral honeys (clover, honeydew, kamahi, manuka, nodding thistle, rata, rewarewa, tawari, thyme and viper's bugloss honey) were determined, as well as moisture content, pH, conductivity and colour. The most abundant minerals were potassium, phosphorus and calcium, ranging between 34.8-3640, 29.5-255 and 7.21-94.3 mg/kg, respectively. Potassium made up 73% of the total mineral content. There was a large range of mean total mineral contents, with honeydew honey having the highest level (4060 mg/kg) and viper's bugloss honey the lowest (126 mg/kg). Honeydew had more than twice the mean total mineral contents than kamahi, the next highest. The heavy metal contents (Cd, Pb and Zn) of the mono-floral honey types investigated were very low. A strong positive relationship between mean conductivity and total mineral content (r(2) = 0.973), and pH and total mineral content (r(2) = 0.776) was observed in this study. (C) 2011 Elsevier Ltd. All rights reserved.
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