scholarly journals Physicochemical Parameters for Brea Gum Exudate from Cercidium praecox Tree

2018 ◽  
Vol 2 (4) ◽  
pp. 72 ◽  
Author(s):  
Martin Masuelli ◽  
Aníbal Slatvustky ◽  
Ariel Ochoa ◽  
M. Bertuzzi
Keyword(s):  
Physicochemical Properties ◽  
Intrinsic Viscosity ◽  
Physicochemical Parameters ◽  
Size Exclusion ◽  
Arabic Gum ◽  
Hydrodynamic Parameters ◽  
Pharmaceutical Applications ◽  
Exclusion Chromatography ◽  
Cercidium Praecox ◽  
Hyperbranched Structure

Brea gum (BG) is a hydrocolloid obtained as an exudate from the Cercidium praecox tree. The physicochemical properties of brea gum are similar to those of the arabic gum and, in many cases, the former can replace the latter. The brea gum was incorporated in 2013 into the Argentine Food Code because of its ancestral background and its current food uses. Brea gum could be also used as additive or excipient for pharmacological formulations. This work reports intrinsic viscosity, coil overlap, and Mark–Houwink–Kuhn–Sakurada (MHKS) parameters of BG solutions. Partially hydrolyzed BG solution was analyzed using intrinsic viscosity measurements, dynamic light scattering and size-exclusion chromatography (SEC). The MHKS parameters, a and k, were determined for BG at 25 °C, with values of 0.4133 and 0.1347 cm3 g−1, respectively. The viscometric molecular weight of BG was 1890 kg mol−1. The hydrodynamic parameters of BG were indicative of a hyperbranched structure and spherical conformation. The knowledge obtained on the physicochemical properties of brea gum favors its use in food and pharmaceutical applications.

scholarly journals Effect of Storage Time on the Physicochemical Properties of Waste Fish Oils and Used Cooking Vegetable Oils

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 101
Author(s):  
Nina Bruun ◽  
Fiseha Tesfaye ◽  
Jarl Hemming ◽  
Meheretu Jaleta Dirbeba ◽  
Leena Hupa
Keyword(s):  
Physicochemical Properties ◽  
Vegetable Oils ◽  
High Performance ◽  
Chemical Properties ◽  
Storage Period ◽  
Small Variation ◽  
Size Exclusion ◽  
Fish Oils ◽  
Renewable Fuels ◽  
Exclusion Chromatography

Waste fish oils (FOs) and used cooking vegetable oils (UCOs) are increasingly becoming alternative renewable fuels. However, different physicochemical aspects of these renewable fuels, including the effect of storage, are not well-known. In this work, the effect of the storage period on physicochemical properties of selected samples of FOs and UCOs was investigated. The bio-oils were stored at 4 °C for up to five years before each experimentation. The chemical properties were characterized using capillary gas chromatography with flame ionization detection (GC-FID) and high-performance size exclusion chromatography including an evaporative light scattering detector (HPSEC-ELSD). Water contents and acid numbers of the bio-oils were determined using the Karl Fischer (KF) titration and the ASTM D 664 methods. Furthermore, the average heating values and surface tension of the bio-oils were determined. According to the results obtained, for all bio-oil types, the concentrations of polymerized triglycerides, diglycerides, and fatty acids and monoglycerides had increased during the storage periods. The physical properties of the bio-oils also showed a small variation as a function of the storage period. The overall results observed indicate that the deterioration of the physicochemical properties of bio-oils can be controlled through storage in dark, dry, and cold conditions.

Polystyrene in N-Methylpyrrolidone: Intrinsic Viscosity-Molar Weight Relations and Polystyrene Unperturbed Dimensions

1993 ◽  
Vol 58 (10) ◽  
pp. 2396-2402
Author(s):  
Martin Konáš ◽  
Allan R. Shultz
Keyword(s):  
Intrinsic Viscosity ◽  
Size Exclusion Chromatography ◽  
Accurate Method ◽  
Size Exclusion ◽  
Unperturbed Dimensions ◽  
Molar Weight ◽  
Exclusion Chromatography ◽  
Weight Data

Intrinsic viscosity-molar weight relations are reported for polystyrene in N-methylpyrrolidine (NMP) and NMP/LiBr solutions at 30, 45, 60, 75, 90 and 105 °C. Also, Mark-Houwink constants KΘ and the unperturbed dimensions of the polystyrene chains at these temperatures are calculated by applying Stockmayer-Fixman extrapolations of the viscosity/molar weight data. The use of in-line size exclusion chromatography and viscometry is shown to be a facile and accurate method for such studies.

CHARACTERIZATION OF A NEW LCAT MUTATION CAUSING FAMILIAL LCAT DEFICIENCY (FLD) AND THE ROLE OF APOE AS A MODIFIER GENE OF THE FLD PHENOTYPE

2009 ◽  
Vol 32 (6S) ◽  
pp. 3
Author(s):  
A Baass ◽  
H Wassef ◽  
M Tremblay ◽  
L Bernier ◽  
R Dufour ◽  
...  
Keyword(s):  
Modifier Gene ◽  
Size Exclusion ◽  
Plasma Lipoproteins ◽  
Lipoprotein Profile ◽  
Exclusion Chromatography ◽  
Low Hdl ◽  
Lcat Deficiency ◽  
Apoe Genotypes

Introduction: LCAT (lecithin:cholesterol acyltransferase ) is an enzyme which plays an essential role in cholesterol esterification and reverse cholesterol transport. Familial LCAT deficiency (FLD) is a disease characterized by a defect in LCAT resulting in extremely low HDL-C, premature corneal opacities, anemia as well as proteinuria and renal failure. Method: We have identified two brothers presenting characteristics of familial LCAT deficiency. We sequenced the LCAT gene, measured the lipid profile as well as the LCAT activity in 15 members of this kindred. We also characterized the plasma lipoproteins by agarose gel electrophoresis and size exclusion chromatography and sequenced several candidate genes related to dysbetalipoproteinemia in this family. Results: We have identified the first French Canadian kindred with familial LCAT deficiency. Two brothers affected by FLD, were homozygous for a novel LCAT mutation. This c.102delG mutation occurs at the codon for His35 causing a frameshift that stops transcription at codon 61 abolishing LCAT enzymatic activity both in vivo and in vitro. It has a dramatic effect on the lipoprotein profile, with an important reduction of HDL-C in both heterozygotes (22%) and homozygotes (88%) and a significant decrease in LDL-C in heterozygotes (35%) as well as homozygotes (58%). Furthermore, the lipoprotein profile differed markedly between the two affected brothers who had different APOE genotypes. We propose that APOE could be an important modifier gene explaining heterogeneity in lipoprotein profiles observed among FLD patients. Our results suggest that a LCAT-/- genotype associated with an APOE ?2 allele could be a novel mechanism leading to dysbetalipoproteinemia.

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