| 1. |
- da Cruz Francisco, José, et al.
(författare)
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Phase behavior of the monoolein-water system - The effects of addition of the hydrocarbon 1,8-cineole and supercritical carbon dioxide
- 2004
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Ingår i: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 31:3, s. 263-271
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Tidskriftsartikel (refereegranskat)abstract
- The results of a study on the phase behavior of the monoolein/water system with the addition of the hydrocarbon 1,8-cineole (C10H18O) and supercritical carbon dioxide at 15 MPa is presented. To two mixtures consisting of 9 and 18 wt.% water in monoolein, 5, 10, and 20 wt.% cineole were added and heated to between 35 and 80 degreesC at atmospheric pressure and in the presence of supercritical carbon dioxide. The phase changes were followed by deuterium nuclear magnetic resonance (H-2 NMR), light microscopy, and ocular inspection. The mesomorphic structures developed in the 9 wt.% water sample suffered little change due to the presence of the supercritical carbon dioxide. However, in the mixture with 18 wt.% water, the native phase structures were dramatically affected and an isotropic fluid phase developed. The addition of cineole has lowered the LC-L-alpha --> LC-H-Pi phase transition in the samples with 9 and 18 wt.% water in monoolein. The surplus of supercritical carbon dioxide in the samples has resulted in similar developments. Regardless of the amount of cineole present in the system, only the isotropic fluid phase was observed in the samples with 18 wt.% water in monoolein. (C) 2004 Elsevier B.V. All rights reserved.
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| 2. |
- da Cruz Francisco, José, et al.
(författare)
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Phase behavior of the system lecithin-water - The effects of addition of the hydrocarbon 1,8-cineole and supercritical carbon dioxide
- 2004
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Ingår i: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 31:3, s. 255-262
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Tidskriftsartikel (refereegranskat)abstract
- The phase behavior of lecithin and water mixtures with addition of the hydrocarbon 1,8-cineole (C10H18O) was investigated using light microscopy and H-2 NMR at atmospheric pressure and with a surplus of supercritical carbon dioxide (15 MPa) between 35 and 80degreesC. The lecithin-water (LW) mixtures consisted of 10 and 20wt.% water in lecithin to which 5, 10, and 20wt.% cineole and supercritical carbon dioxide were added. The addition of cineole to the 10wt.% water in lecithin samples has affected the original lamellar liquid crystalline phase present and mainly transformed it into the reversed hexagonal phase at cineole concentration of 10wt.% and higher. This phase however Only Occurred when 20 wt.% cineole were added to the lecithin samples with 20wt.% water which otherwise was lamellar. The addition of supercritical carbon dioxide to the lecithin/water samples in the absence of cineole resulted in a liquid crystalline lamellar (LC-L-alpha) phase and was the same as in the original phase structure at atmospheric pressure. In the lecithin/water samples with cineole, the addition of supercritical carbon had little effect on the structure. (C) 2004 Elsevier B.V. All rights reserved.
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| 3. |
- Francisco, J D, et al.
(författare)
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Liquid crystalline properties and extractability of monoolein-water systems by supercritical carbon dioxide
- 2003
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Ingår i: Colloids and Surfaces A: Physicochemical and Engineering Aspects. - 0927-7757. ; 213:1, s. 69-78
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Tidskriftsartikel (refereegranskat)abstract
- The influence of phase structure on the extraction recovery of monoolein from monoolein-water systems by supercritical carbon dioxide was investigated. Two monoolein-water mi tures at concentrations of 9 wt% water and 18 wt% water, respectively, were studied. H-2-NMR was used to monitor changes of the phase structures in supercritical conditions. The results showed that the phase structure and the water-monoolein interactions play a role on the extraction yield. The monoolein recovery was higher in the 9 wt% water sample in which L-alpha phase was present compared to the 18 wt% water sample in which the L-alpha melted to yield a L-2 phase. When the phase structures were the same in both samples, the extraction recovery was determined by the solubility properties of the components of the system. The changes due to the presence of supercritical carbon dioxide were shown also to depend on the water concentration of the monoolein-water mixture besides the temperature. The 18 wt% mixture showed a L-2 phase structure in all the range of the temperature investigated while the 9 wt% water mixture showed phase changes from L-alpha phase to L-2 phase in the same temperature range. (C) 200 Elsevier Science B.V. All rights reserved.
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| 4. |
- Lin, Qin-Lu, et al.
(författare)
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Effect of colloidal structures on the stability of five flavonoids with different hydrophilicity
- 2008
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 22:4, s. 700-705
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Tidskriftsartikel (refereegranskat)abstract
- Autoxidation of five flavonoids representing range of different hydrophilicities (epicatechin gallate (ECG), (+) catechin((+)Q, epicatechin (EC), epigallocatechin gallate (EGCG) and epigallocatechin (EGC)) in three different aqueous solutions: molecular solution, micellar solution (Tween 20) and liposoml dispersion (soybean lecithin) was monitored by HPLC. The rate of oxidaton of the five flvonoids was higher at pH 4.5 than at pH 3.5. Compared with the control, addition of Tween-20 (micellar structure) and lecithin (liposomal structure) significantly decreased the degradation of flavonoids. In the presence of lecithin the autoxidation of all the five flavonoids was slower than in the presence of Tween-20. The effective protection of the colloidal structures was compared the hydrophilicity of the flavonoids estimated from the partitioning between octanol and water. The protection from oxidation in the presence of the colloidal structures (micellar or liposomal) increased with increasing partitioning of a flavonoid towards the hydrophobic environment. The protecting effect of the colloidal structures was more effective at pH 4.5 than at pH 3.5.
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| 5. |
- Penarrieta, Mauricio, et al.
(författare)
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Total antioxidant capacity and content of flavonoids and other phenolic compounds in canihua (Chenopodium pallidicaule): An Andean pseudocereal
- 2008
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Ingår i: Molecular Nutrition and Food Research. - : Wiley. - 1613-4133 .- 1613-4125. ; 52:6, s. 708-717
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Tidskriftsartikel (refereegranskat)abstract
- Total antioxidant capacity (TAC), total phenolic compounds (TPH), total flavonoids (TF) and individual phenolic compounds were determined in canihua collected at approx. 3850 in altitude. The TAC values varied among samples from 2.7 to 44.7 by the ferric reducing antioxidant power (FRAP) method and from 1.8 to 41 by the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) method expressed as mu mol of Trolox equivalents/g dw. The content of TPH was 12.4-71.2 mu mol gallic acid equivalents/g dw and that of the TF ranged between 2.2 and 11.4 mu mol of catechin equivalents/g dw. The data obtained by the four methods showed several significant Correlations. Prior to analysis by HPLC, the samples were subjected to acid hydrolysis and in the water-soluble extracts this led to an up to 20-fold increase in the TAC values in comparison with the values of the nonhydrolysed samples. HPLC analysis showed the presence of eight major compounds identified as catechin gallate, catechin, vanillic acid, kaempferol, ferulic acid, quercetin, resorcinol and 4-methylresorcinol. Their estimated contribution to the TAC value (FRAP method) indicated that resorcinols contributed most of the antioxidant capacity of the water-soluble extract. The results show that canihua is a potential source of natural antioxidant compounds and other bioactive compounds which can be important for human health.
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| 6. |
- Penarrieta, Mauricio, et al.
(författare)
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Total Antioxidant Capacity and Content of Phenolic Compounds in Wild Strawberries (Fragaria vesca) Collected in Bolivia
- 2009
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Ingår i: International Journal of Fruit Science. - : Informa UK Limited. - 1553-8362 .- 1553-8621. ; 9:4, s. 344-359
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Tidskriftsartikel (refereegranskat)abstract
- To study the composition of wild strawberries grown at high altitude, total antioxidant capacity, total phenolic compounds, total flavonoids, and individual phenolic compounds were measured in wild strawberries (Fragaria vesca) collected between 2,650 and 3,300 m above sea level in Bolivia. Total antioxidant capacity, as assessed by the ferric-reducing antioxidant power and 2,2¢-azinobis( 3-ethylbenzotiazoline-6-sulphonic acid) methods, was in the range 16-39 mmol of Trolox equivalents/g fw by both methods. The total phenolic content was 9.7–21 mmol gallic acid equivalents/g fw, and the flavonoid content ranged between 2.8 and 4.9 mmol of catechin equivalents/g fw. The data obtained by the four methods showed several significant linear correlations confirming that flavonoids and other phenolic compounds contributed significantly to the total antioxidant capacity values. Reversed-phase high performance liquid chromatography analysis of extracts subjected to acid hydrolysis showed the presence of seven major fractions, tentatively identified as ellagic acid, cyanidin, pelargonidin, quercetin, kaempferol, gallic acid derivatives, and catechin derivatives. The data indicated that wild strawberries have a somewhat higher total antioxidant capacity content in comparison with that reported for cultivated strawberries. No obvious difference to the composition reported for wild strawberries grown at low altitude could be found.
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| 7. |
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| 8. |
- Alftrén, Johan, et al.
(författare)
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Comparison of molecular and emulsifying properties of gum arabic and mesquite gum using asymmetrical flow field-flow fractionation
- 2012
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X. ; 26:1, s. 54-62
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Tidskriftsartikel (refereegranskat)abstract
- The molecular and emulsifying properties of gum arabic (GA) and mesquite gum (MG) were characterized using asymmetrical flow field-flow fractionation connected to multi-angle light scattering and refractive index detection. Properties such as molar mass, root-mean-square radius (rrms), hydrodynamic radius (rh), conformation, apparent densities and distribution of proteinaceous matter over the whole molar mass range were determined. GA displayed a low molar mass (3.4 × 105 g/mol), protein-poor component (population 1) and a high molar mass (1.9 × 106 g/mol), protein-rich component (population 2). MG displayed one molar mass population with an average molar mass of 1.1 × 106 g/mol. For both GA and MG, the conformation (rrms/rh) was increasingly spherical with increasing molar mass. However, MG had higher values of rrms/rh for a specific molar mass suggesting differences in structure between GA and MG. The protein content increased with increasing molar mass for both gums, although to a higher extent for GA. Selective adsorption, during emulsification experiments, could be observed of population 2 of GA which may be due to a combination of the higher protein content and a more flexible structure rendering it more surface active than population 1. Comparing GA and MG in terms of emulsion stability, it could be concluded that GA-stabilized emulsions have considerably higher stability against coalescence.
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| 9. |
- Andersson, Ida Marie, et al.
(författare)
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Effects of feed composition, protein denaturation and storage of milk serum protein/lactose powders on lactosylation
- 2021
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423 .- 1365-2621. ; 56:1, s. 480-492
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Tidskriftsartikel (refereegranskat)abstract
- During whey powder production, the feed is subjected to several heat treatments which can cause lactosylation of proteins. In this study, lactosylation of whey proteins was evaluated in spray-dried powders before and after storage by varying the native protein fraction as well as the serum protein/lactose ratio in the powders. The lactosylation of native α-lactalbumin and β-lactoglobulin in the powders before storage was not affected to a large extent by the protein denaturation or if the feed had been heat treated in a high or low lactose environment. After storage (relative humidity of 23.5%, 30 °C, 25 days), the kinetic of lactosylation tended to increase with increasing native protein fraction and bulk protein content in the powders. An explanation could be that proteins dissolved in the lactose glassy structure might have a lower reactivity, while proteins present in the protein glassy structure with dissolved lactose may display higher lactosylation reactivity.
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| 10. |
- Andersson, Kristina E, et al.
(författare)
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Effects of oats on plasma cholesterol and lipoproteins in C57BL/6 mice are substrain specific.
- 2010
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Ingår i: British Journal of Nutrition. - 1475-2662. ; 103, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- Cholesterol-lowering effects of oats have been demonstrated in both animals and human subjects. However, the crucial properties of oat-containing diets that determine their health effects need to be further investigated to optimise their use. A mouse model would be a valuable tool, but few such studies have been published to date. We investigated the effects of oat bran on plasma cholesterol and lipoproteins in two substrains of C57BL/6 mice. Western diet was made atherogenic by the addition of 0.8 % cholesterol and 0.1 % cholic acid. After 4 weeks on atherogenic diet, total plasma cholesterol had increased from 1.86-2.53 to 3.77-4.40 mmol/l. In C57BL/6NCrl mice, inclusion of 27 and 40 % oat bran reduced total plasma cholesterol by 19 and 24 %, respectively, reduced the shift from HDL to LDL+VLDL and caused increased faecal cholesterol excretion. There was no effect of oat bran on plasma levels of the inflammatory markers fibrinogen, serum amyloid A or TNF-alpha. Contrary to findings in C57BL/6NCrl mice, there was no sustained effect of oat bran (27 or 40 %) on plasma cholesterol in C57BL/6JBomTac mice after 4 weeks of feeding. Thus, C57BL/6NCrl mice fed an atherogenic diet are a good model for studies of physiological effects of oats, whereas a substrain derived from C57BL/6J, raised in a different breeding environment and likely possessing functional genetic differences from C57BL/6N, is considerably less responsive to oats. The present finding that two substrains of mice respond differently to oats is of practical value, but can also help to elucidate mechanisms of the cholesterol-lowering effect of oats.
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