| 1. |
- Axling, Ulrika, et al.
(author)
-
Rye bran alkylresorcinols suppress adipocyte lipolysis and hormone-sensitive lipase activity
- 2011
-
In: Molecular Nutrition and Food Research. - : Wiley. - 1613-4133 .- 1613-4125. ; 55, s. 290-293
-
Journal article (peer-reviewed)abstract
- The effects of alkylresorcinols (ARs) isolated from rye bran on adipocyte lipolysis, hormone-sensitive lipase activity and phosphorylation and on phosphorylation of protein kinase A substrates were studied. Preincubation with ARs for 18 h suppressed catecholamine-stimulated lipolysis in 3T3-L1 adipocytes. Furthermore, phosphorylation of hormone-sensitive lipase (HSL), a key lipase responsible for stimulated lipolysis, and phosphorylation of protein kinase A substrates, were diminished after preincubation with ARs, whereas HSL protein expression was unaltered. ARs were also shown to inhibit HSL activity in an in vitro assay.
|
|
| 2. |
- Bhand, Sunil, et al.
(author)
-
Fructose-selective calorimetric biosensor in flow injection analysis.
- 2010
-
In: Analytica Chimica Acta. - : Elsevier BV. - 1873-4324 .- 0003-2670. ; 668:1, s. 13-18
-
Journal article (peer-reviewed)abstract
- A highly selective, interference free biosensor for the measurement of fructose in real syrup samples was developed. The assay is based on the phosphorylation of D(-)fructose to fructose-6-phosphate by hexokinase and subsequent conversion of fructose-6-phosphate to fructose-1,6-biphosphate by fructose-6-phosphate-kinase. The heat liberated in the second reaction is monitored using an enzyme thermistor. The major advantages of this biosensor are rapid and selective measurement of fructose without the need to eliminate glucose and inexpensive FIA-based, mediator-free calorimetric measurement suitable for regular fructose analysis. This method was optimised for parameters, such as pH, ionic strength, interference, operational stability and shelf life. Good and reproducible linearity (0.5-6.0 mM) with a detection limit of 0.12 mM was obtained. Fructose determination in commercial syrup samples and spiked samples confirmed the reliability of this set-up and technique. The biosensor gave reproducible results with good overall stability for continuous measurements over a period of three months besides a useful shelf life of six months. The method could be used for routine fructose monitoring in food samples.
|
|
| 3. |
- da Cruz Francisco, José, et al.
(author)
-
Application of supercritical carbon dioxide for the extraction of alkylresorcinols from rye bran
- 2005
-
In: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 35:3, s. 220-226
-
Journal article (peer-reviewed)abstract
- The use of supercritical CO, (SC-CO2) for extracting alkylresorcinols from rye bran was investigated. For pure SC-CO2, 35 MPa and 55 degrees C were used. SC-CO2 with 10% ethanol or methanol as co-solvents was tested at four pressure levels (8, 15, 30 and 35 MPa) and two temperatures (40 and 55 degrees C). Experiments were conducted at a constant SC-CO2 flow of 5 g/min for 2 h. For comparative purposes acetone at ambient temperature and pressure was also used for extraction. The best extractions were achieved when SC-CO2 was used with co-solvents. At 55 degrees C and 15-30 MPa, the use Of SC-CO2 with co-solvents has yielded from 8 to 80% (w/w) more extracted product than acetone. Yield of extracts was proportional to pressure (when above 30 MPa) and temperature. The results suggest that cleaner bran extracts can be obtained by using pure SC-CO2 followed by the addition of co-solvents. There is no clear advantage of using either methanol or ethanol. (c) 2005 Elsevier B.V. All rights reserved.
|
|
| 4. |
- da Cruz Francisco, José, et al.
(author)
-
Extraction of rye bran by supercritical carbon dioxide: Influence of temperature, CO2, and cosolvent flow rates
- 2005
-
In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 53:19, s. 7432-7437
-
Journal article (peer-reviewed)abstract
- Process parameter optimization for the supercritical CO2 extraction of rye bran to obtain alkylresorcinols (AR) was studied by carrying out a two-level fractional design experiment. Four parameters, temperature, CO2 flow rate, cosolvent percentage, and extraction time, presumed to influence the extraction process, were analyzed. A tentative fractionation of the crude extract was also carried out and is discussed. The best extracts were achieved when the CO2 flow rate and extraction time or temperature and cosolvent addition were kept high. It was found that temperature increase was not statistically significant within the range of the study performed, and the extraction time was thus the most important factor. A preliminary fractionation process in two cyclone separators yielded two fractions, one rich in AR components with higher molecular weights and the other rich in AR components with low molecular weight.
|
|
| 5. |
- da Cruz Francisco, José, et al.
(author)
-
Isolation of alkylresorcinols: Classical and supercritical CO2 extraction methods
- 2006
-
In: Modern Extraction Techniques: Food and Agricultural Samples (ACS Symposium). - 0097-6156. - 9780841239401 - 0841239401 ; 926, s. 51-61
-
Book chapter (other academic/artistic)abstract
- This chapter focuses on the use of different methods for isolation of alkylresorcinols. Alkylresorcinols are members of a lipid group called non-isoprenoid phenolic lipids. Different aspects of the extraction by classical methods and supercritical CO2 are discussed. Supercritical CO2 extraction of alkylresorcinols from rye bran is discussed for the first time. As compared to the classical extraction methods, supercritical CO2 gives higher yields and it allows the separation of the crude extrac into long- and short-chain alkylresorcinol homologues.
|
|
| 6. |
- da Cruz Francisco, José, et al.
(author)
-
Supercritical Carbon Dioxide in the Biotechnology of Amphiphiles
- 2005
-
In: Cellular & Molecular Biology Letters. - 1689-1392. ; 10:Suppl. 1, s. 105-105
-
Journal article (peer-reviewed)abstract
- This article is an overview, introducing the currently used supercritical carbon dioxide (scCO2) based technology in association to biotechnological applications. Within each application, the basic principles of the technique, a description of the instrumentation, methodology, and problems encountered, and advantages over the traditional methods are discussed. The areas covered in this paper include pure supercritical CO2 properties, coـsolvents role, and the interactions between the scCO2 and the amphiphiles involved. Extraction and reaction are discussed.
|
|
| 7. |
- da Cruz Francisco, José, et al.
(author)
-
Supercritical Fluids as Alternative, Safe, Food-Processing Media: An Overview.
- 2003
-
In: Acta Microbiologica Polonica. - 0137-1320. ; 52:Suppl., s. 35-43
-
Journal article (peer-reviewed)abstract
- The continuous growth of world population and its concentration in the urban areas require food supplies that are continuous, sufficient and of good quality. To resolve this problem techniques have been developed for increasing food quantity and quality. The techniques are applied throughout the food chain from production, conservation and during distribution to the consumers (from "the field to the fork"). During handling of food, chemicals are often deliberately added to achieve improved processing and better quality. This is one of the main reasons food undergoes different kinds of contamination. This overview focuses on the application of supercritical fluids as media for handling food materials during processing with the perspective of reducing chemical contamination of food. Examples of developmental applications of this technique and on research work in process are presented. Emphasis is given to extraction and biotransformation techniques.
|
|
| 8. |
- Dey, Estera, et al.
(author)
-
A food grade approach for the isolation of major alkylresorcinols (ARs) from rye bran applying tailored supercritical carbon dioxide(scCO(2)) extraction combined with HPLC
- 2009
-
In: Journal of Supercritical Fluids. - : Elsevier BV. - 0896-8446. ; 51:2, s. 167-173
-
Journal article (peer-reviewed)abstract
- Tailored supercritical carbon dioxide (scCO(2)) extraction of alkyhesorcinols (ARs) from rye bran resulting in pre-purification of ARs already during extraction process. The pre-purification was achieved by splitting the extraction process in 2 steps.. In both steps, the CO2 pressure was set at 25 MPa with a flow rate of 10 g/min. The first step was carried out at 70 degrees C. 0.06% of ethanolic co-solvent for 2 h, followed by the second step at 45,C using 10% of ethanolic co-solvent for 4 h, resulting in a pre-purified ARs extract. From the pre-purified scCO(2) extract, chromatographed on C8 column, were obtained pure ARs homologues of C17, C19 and C21 (68% of total) eluting separately in a linear gradient of ethanol. Additionally, a rapid method for the isolation of high purified pools of ARs homologues using a disposable solid phase extraction SPE-C18 column and a step gradient of ethanol was developed. (C) 2009 Elsevier B.V. All rights reserved.
|
|
| 9. |
- Dey, Estera, et al.
(author)
-
A novel approach for characterization of exopolymeric material in sewage sludge
- 2006
-
In: Journal of Residuals Science and Technology. - 1544-8053. ; 3:2, s. 97-103
-
Journal article (peer-reviewed)abstract
- The digestibility of sludge is dependent on the content of organic extra-cellular polymeric substances. Currently the most appropriate and rapid assessment methods for the organic content of wastewater are the chemical oxygen demand and volatile solids values. These parameters also measure the non-biodegradable organics. We have developed a method to predict sewage sludge digestibility and the appropriate composition of enzymes needed. Sludge is treated with selected enzymes and the released products characterized using a lectin panel. One protease and several glycosidases were selected and applied under mild conditions to minimize lysis of cells in the sludge. Combinations of enzymes with and without sodium triphosphate pentabasic were studied. Partially enzymaticaly hydrolyzed extra-cellular polymeric substances and the released glycoconjugates were quantitatively determined by conventional methods. Surface plasmon resonance was used to investigate the interaction of extracts with a lectin panel.
|
|
| 10. |
- Dey, Estera, et al.
(author)
-
Alkylresorcinols isolated from rye bran by supercritical fluid of carbon dioxide and suspended in a food-grade emulsion show activity against Penicillium expansum on apples
- 2013
-
In: Archives of Phytopathology and Plant Protection. - : Informa UK Limited. - 1477-2906 .- 0323-5408. ; 46:1, s. 105-119
-
Journal article (peer-reviewed)abstract
- Apple cultivars are attacked by many fungal diseases, both on the tree and during storage. One of the most serious is blue mould, caused by Penicillium expansum. In this study, 5-(n)-alkylresorcinols (AR) were isolated from rye bran by the supercritical fluid of carbon dioxide and were used for the preparation of bioactive emulsions. These emulsions were applied to harvested fruit of five apple varieties to determine the levels of antifungal activity. A significant inhibition of disease symptoms was obtained after spraying some of the prepared AR emulsions on fruits that had been experimentally infected with Penicillium expansum. The most effective emulsions consisted of 0.025% (m/v) ARs, 0.1% (m/v) xanthan gum, 0.5% (m/v) Synperonic 91/6 or PDMs-copolymer, 0.2% (m/v) Tween 20, 1% (m/v) Trioleate, 2% (m/v) oleylalcohol, 2% (m/v) PEG 400, 5% (m/v) CaCl2 or NaCl suspended in water.
|
|
