Search results for "Degree of unsaturation"
showing 5 items of 25 documents
Absorption and intestinal catabolism of fatty acids in the rat: effect of chain length and unsaturation
1991
Simultaneous portal blood absorption and intestinal mucosal catabolism of labelled fatty acids were investigated. Anaesthetized adult Wistar rats were infused intraduodenally either with 90 mumol of capric (C10:0), oleic (C18:1), linoleic (C18:2) or arachidonic (C20:4) 1-14C acids or with 30 mumol of each labelled fatty acid in addition to 30 mumol of oleic acid and 30 mumol of monopalmitin. For mixed infusates, experiments were carried out with two additional long-chain fatty acids: palmitic (C16:0) and erucic (C22:1) 1-14C acids. Radioactivity was quantified in the lipids and in the catabolic products in portal blood recovered at 5 min intervals for 1 h after infusion. At the end of the e…
Effect of pHand age of culture on cellular fatty acid composition of Leuconostoc oenos
1996
Z. DRICI-CACHON, J.F. CAVIN AND C. DIVIES. 1996. This study is concerned with the fatty acid composition of three strains of Leuconostoc oenos grown at different pH. The most abundant fatty acids were C18: 1w9, C19: 0 cy(w9,10) and C16:0, followed by C16: 1w9 and C14: 0. The pH considerably modified the fatty acid distribution in Lo107 (an acidophilic strain) and Lo8413 (a moderately acidophilic strain). However, moderate changes occurred for LoATCC 23277 (a less acidophilic strain). At pH 2.9, Lo107 has a remarkably high level of C19: 0 cy-(w9,10) and C19:0 cy(w11,12). Proportions of C18: 1 and C19:0 cyclo acids varied mainly with the pH of the medium and also as a function of growth phase…
Determination of unsaturation grade and trans isomers generated during thermal oxidation of edible oils and fats by FTIR
1999
Abstract The oxidative deterioration of culinary oils and fats during episodes of heating associated with normal usage (80°C–300°C, 20–40 min) was monitored by FTIR spectroscopy. The thermal oxidation of polyunsaturated fatty acids during heating was studied by the determination of unsaturation percentage and trans isomers at various temperatures and heating times. Oils frequently used in food frying such as olive oil, sunflower oil, corn oil and seeds oil (sunflower, safflower and canola seed), and lard were studied. The Absorbance Correction Method is proposed to correct the spectral interference and allows the analytic use of signal which would not be initially valid for quantitative ana…
Analytical evaluation of polyunsaturated fatty acids degradation during thermal oxidation of edible oils by Fourier transform infrared spectroscopy
1998
The oxidative deterioration of polyunsaturated fatty acids (PUFAs) in culinary oils and fats during episodes of heating associated with normal usage (80-300 degrees C, 20-40 min) has been monitored by Fourier transform infrared spectroscopy (FTIR). The thermal oxidation of PUFAs is a free radical chain reaction, in which hydroperoxides are generally recognized as the primary major products. Hydroperoxides of PUFAs are easily decomposed into a very complex mixture of secondary products with the decrease in unsaturation. The oxidative advance of PUFAs during heating was studied by the determination of unsaturation percentage at different temperatures and heating times. Oils frequently used in…
Role of Weak Hydrogen Bonds and Halogen Bonds in 5-Halo-1,3-dimethyluracils and Their Cocrystals—A Combined Experimental and Computational Study
2016
Seven single crystals containing either N,N-dimethyluracil (DMHU) or one of its 5-halogenated derivatives (DMXU; X = F, Cl, Br, I) were prepared using N,N-dimethylformamide as the crystallization solvent. Single crystal X-ray diffraction and quantum chemical calculations carried out at the spin component scaled local MP2 level of theory were then used to study the intramolecular halogen and nonconventional hydrogen bonds present in the structures. The results were compared to and contrasted with the previously reported data for uracil and its halogenated derivatives. In particular, the intermolecular interactions in DMIU were compared to the halogen and hydrogen bonds in 5-iodouracil that, …