Search results for "Analytical"
showing 10 items of 9586 documents
Biocatalyzed acidolysis of soybean oil triacylglycerols to increase oleic acid content
2004
Lipase catalyzed acidolysis of triacylglycerols (TAG) of soybean oil with oleic acid in organic solvent was studied; immobilized lipase from Rhizomucor miehei was used and the effects of reaction time, incubation temperature and enzyme load on TAG total and positional fatty acid (FA) percentage compositions were investigated. The results show that oleic acid incorporation was high after 24 and 48 h, while after 72 h a lower level of oleic acid in TAG was observed. Moreover, for the reactions carried out at 30 and 40 degrees C, it was observed that the oleic acid level was about 46.5% while ligtly higher values (about 49%) were observed at 50 degrees C; however, under this last condition, th…
Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India.
2011
The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC–MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9–95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4–41.8%) was the main compound, followed by eugenyl acetate (0.0–47.1%) and α-phellandrene (0.6–2.5%) in the analysed oils.
Spectroscopic analyses of the influence of electron beam irradiation doses on mechanical, transport properties and microstructure of chitosan-fish ge…
2015
International audience; The objective of this work was to better display the effect of electron beam accelerator doses (0, 20, 40 and 60 kGy) on structural, mechanical and barrier properties of edible lightly plasticized chitosan-fish gelatin blend film. From Electron Spin Resonance (ESR), signal at 3500 G for blend film was identified as free radical formation during irradiation, which might introduce intermolecular cross-linking into the polymer matrix, thus affecting structural properties. Tensile Strength (TS) for gelatin film significantly increased with growing irradiation doses (improved by 30% for 60 kGy), but the TS of chitosan and blend films were not significantly affected. On th…
Impact of electron beam irradiation on fish gelatin film properties
2016
International audience; The objective of this work was to display the effect of electron beam accelerator doses on properties of plasticized fish gelatin film. Electron spin resonance indicates free radical formation during irradiation, which might induce intermolecular cross-linking. Tensile strength for gelatin film significantly increases after irradiation (improved by 30% for 60 kGy). The vapour permeability is weakly affected by irradiation. Surface tension and its polar component increase significantly and are in accordance with the increase of wettability. So, irradiation may change the orientation of polar groups of gelatin at the film surface and crosslink the hydrophobic amino aci…
Understanding the Effects of Crosslinking and Reinforcement Agents on the Performance and Durability of Biopolymer Films for Cultural Heritage Protec…
2021
In the last two decades, the naturally occurring polysaccharides, such as chitosan and pectin, have gained great attention having potential applications in different sectors, from biomedical to new generation packaging. Currently, the chitosan and pectic have been proposed as suitable materials also for the formulation of films and coatings for cultural heritage protection, as well as packaging films. Therefore, the formulation of biopolymer films, considering only naturally occurring polymers and additives, is a current challenging trend. This work reports on the formulation of chitosan (CS), pectin (PC), and chitosan:pectin (CS:PC) films, also containing natural crosslinking and reinforce…
Antimicrobial and Antioxidant Activities of Coumarins from the Roots of Ferulago campestris (Apiaceae)
2009
We report the isolation of several coumarins and the stereochemical assessment of some pyranocoumarins, as well as the antibacterial and antioxidant activities of the three most abundant ones (grandivittin, agasyllin and aegelinol benzoate) isolated from the roots of Ferulago campestris collected in Sicily and of the hydrolysis product (aegelinol). Aegelinol and agasyllin showed antibacterial activity against nine ATCC and the same clinically isolated Gram-positive and Gram-negative bacterial strains. At a concentration between 16 and 125 μg/mL both coumarins showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Staph…
Small-angle neutron scattering from lecithin reverse micelles
1996
Abstract We report new results of small-angle neutron scattering from cyclohexane- d 12 /lecithin/water micellar solutions, performed as a function of the water content, w 0 , the temperature, T and the dispersed-phase volume fraction, ф. The data from dilute samples can be interpreted in terms of the existence of giant cylindrical reverse micelles, in good agreement with the current idea of an unlimited micellar growth with ф. In contrast, the appearance of a sharp interference maximum at high concentrations ( ф > 0.15 ) suggests that the current hypothesis of a gel structure interpreted as a random network of entangled micelles can be assumed to be incorrect, and that there must be some c…
Essential Oil Composition of the Aerial Parts of FiveOcimumspecies from Western India
2015
AbstractChemical composition of the essential oils of five Ocimum species namely Ocimum tenuiflorum syn Ocimum sanctum L. (green and purple), Ocimum kilimandscharicum Guerke, Ocimum viride Willd, Ocimum basilicum L. and Ocimum gratissimum L., obtained by a hydrodistillation was determined by GC and GC-MS. A total of one hundred three compounds were identified in the oils of five Ocimum species, of which fifteen compounds were found to be major (5.0–81.8 %) compounds. Analysis of Ocimum viride oil showed the highest amount of eugenol (81.8 %) among species besides germacrene D (7.0 %) and cis-ocimene (4.1 %). Ocimum tenuiflorum green and Ocimum tenuiflorum purple were found contain eugenol (…
Structure of calcium and zinc pectinate films investigated by FTIR spectroscopy
2010
International audience; Calcium and zinc pectinate gels were prepared using a method which allowed calcium or zinc to diffuse from the cross-linking solution through a dialysis membrane to form a gel with amidated low-methoxyl pectin. The gel thus obtained was then dried, and the film structure was studied using FTIR spectroscopy as a function of the cation content (0%, 5%, 10%, and 15% w/v). Important consideration was given to the three functional groups (amide, carboxyl ester, and carboxylate groups) present in the pectin. When the zinc content was increased, the three wavenumber values corresponding to these three functional groups did not change significantly, while for calcium pectina…
Influence of flavour transfer between different gel phases on perceived aroma
2007
International audience; Multiphasic models of stirred fruit yoghurts made from a bilayer that consisted of a pectin and a dairy gel were developed in order to study the transfer of strawberry flavour compounds between the two phases. Several parameters (i.e., the flavour concentration, the fat content of the dairy gel and the storage temperature) affecting flavour compound transfer, using an experimental design, together with their effect on sensory perception were investigated. Strawberry flavour transfer between the two gels was high enough to affect the sensory perception of the dairy gels. The parameters that modified the partitioning of ethyl esters between the pectin and dairy gel (i.…