This study elucidate the modification on oxidative and thermal stability of acid olive oils during the neutralization step. The neutralization of an acidified olive oil, chosen as model, was carried out by substituting lime (calcium hydroxide) for soda (sodium hydroxide) as the neutralizing agent. Resulting olive oil preserved almost 95% of their α-tocopherol content and had higher temperatures of thermal decomposition than oils neutralized with soda. Oils neutralized with lime had better oxidative stability since the losses of their natural antioxidants, particularly tocopherols, were very limited. The neutralization with soda was accompanied by a passage of epoxides and hydroperoxides (products of first stage of oxidation) to α, β-unsaturated aldehydes and ketones (products of second stage of oxidation). These purposes were confirmed by thermal spectrophotometric analyses and the increase of the carbonyl value after neutralization.
as a botanical source, variability in chia seed composition could be expected between growing locations, and between years within a location, due to genotype and environment effects as well genetic x environment’s interactions. The objective of the present study was to determine the location effect on the growing cycle length, and seed’s protein content, lipid content, and fatty acid profiles, of a single chia genotype. Seeds of chia genotype Tzotzol grown on eight sites in five different ecosystems were tested. One site was in Argentina, in the Semi-Arid Chaco ecosystem (T5); one was in Bolivia, in the Sub-Humid Chaco ecosystem (T4); and six in Ecuador, one in the Coastal Desert (T3), two on the Tropical Rain Forest (T2), and three in the Inter-Andean Dry Valley ecosystem (T1). Seeds from plants grown in T4 and in T3 contained significantly (P <0.05) more protein percentage than did seeds from the other three ecosystems. No significant (P <0.05) differences in protein content were found between T3 and T4, and between T1, T2, and T5. Seeds from T1 and T5 ecosystems, with 33.5 and 32.2%, respectively, were the numerically highest oil content producers, but their results were only significantly (P <0.05) higher when compared with the T2 seeds. Significant (P <0.05) differences in palmitic, stearic, oleic, linoleic and α-linolenic fatty acids between oils from seeds grown in different ecosystems were detected, however. Oil of seeds grown in the T3 ecosystem had the palmitic, stearic and oleic fatty acids’ highest contents. Palmitic and oleic fatty acid levels were significantly (P <0.05) higher when were compared to that of seeds grown in the T1 ecosystem, and stearic when was compared to that of seeds grown in the T5 ecosystem; ω-6 linoleic fatty acid content was significantly (P <0.05) lower in oils of seeds produced in T1, and T2 than in those produced in T3, T4, and T5 ecosystems; ω-3 α-linolenic fatty acid content was significantly (P <0.05) higher in seeds produced in T1, than in those produced in T3, T4, and T5, but not in those produced in T2.
Several studies have shown that dietary alpha-linolenic acid (ALA) is associated with a reduced risk of cardiovascular disease and has an antihypertensive effect. Blood pressure is regulated mainly by angiotensin-converting enzyme (ACE). In the present study, we investigated the effect of dietary ALA on ACE to clarify the mechanism of the antihypertensive effect in spontaneously hypertensive rats (SHR). Six-week-old SHR were fed a diet containing either 10% ALA-rich flaxseed oil or high oleic safflower oil as a control for four weeks. Systolic blood pressure (SBP) was measured by the tail cuff method once weekly. At the end of the feeding period, ACE activity was determined in the heart, aorta, lung and kidney. ACE mRNA in these organs was also measured by real-time PCR analysis. SBP in the ALA group was significantly lower than in the control group at 2, 3, and 4 weeks. The ACE activity and mRNA expression levels in the ALA group were significantly lower than in the control only in the aorta. In conclusion, the present findings suggest that the blood pressure-lowering mechanism of dietary ALA may be involved in the reduction of ACE activity and mRNA expression levels in the aorta of SHR.
We investigated the phase behavior, formation, and rheology of the cubic phase (I1) and related O/I1 gel emulsion in water/Tween 80/oil systems using squalane, liquid paraffin (LP), and decane as oil components. In the phase behavior study, the phase sequences were similar for squalane and LP systems, while a lamellar liquid crystal (Lα) was observed for decane system. In all the systems the addition of oil to Wm or H1 phase induced the I1 phase, which can solubilize some amounts of oil followed by the appearance of I1+O phase. The formation of the O/I1 gel emulsion has been studied at a fixed w/s (50/50) and we found that 30 wt% decane, 70 wt% squalane, and 60 wt% LP can form the gel emulsion. The water/Tween 80/squalane system has been taken as a model system to study viscoelastic properties of the I1 phase and O/I1 gel emulsion. The I1 phase shows a typical hard gel cubic structure under the frequency and the values of the complex viscosity, ¦η*¦ and the elastic modulus, G ′ increase with the addition of squalane, which could be due to the neighboring micellar interaction. On the other hand, the decreasing values of the viscoelastic parameters in the O/I1 gel emulsion simply relate to the volume fraction of the I1 phase in the system.
The effect of a local anesthetic, lidocaine hydrochloride (LC·HCl), on the bilayer systems of purified egg phosphatidylcholine (EPC), dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) was studied by means of small-angle X-ray scattering (SAXS), Prodan fluorescence and electrophoretic light scattering. In the liquid crystalline phase of EPC and DOPC bilayers, the contraction of lamellar distance by ca. 0.8 - 1.0 nm and the decrease of average vesicle size were observed in the presence of LC·HCl. The adsorption of LC·HCl on the vesicle interface brought about the lateral expansion of bilayers and the decrease in the radius of curvature of vesicles. The contraction in the lamellar distance of EPC bilayer caused by high concentration of LC·HCl is attributable to the chain folding in the liquid crystalline state. In the gel phase of DPPC bilayer, the contraction of the lamellar distance in the presence of 0.37 M LC·HCl amounts to 1.6 nm, and the emission maximum of Prodan fluorescence was red-shifted from 440 nm to 518 nm. These phenomena are attributed to the formation of LC·HCl-induced interdigitated gel phase.
We compared the fatty acid compositions including the n-3 and n-6 polyunsaturated fatty acids families in the red blood cell membranes of 26 healthy normal subjects to those with coronary heart disease. The main finding was a significant decrease in the level of docosahexanoic acid (DHA, 22:6 n-3) in coronary heart disease patients. In addition, an increase in n-6/n-3 ratio, and a decrease in the ratio of 22:6/18:3 (n-3) and in omega-3 index was also observed in coronary heart disease patients. The reduction in 22:6/18:3 (n-3) ratio suggests a defect in the elongation and desaturation steps in the n-3 series. The findings in this study also suggest that the low dietary value of fish from Bahrain water may have resulted in a modest dietary intake of DHA and eicosapentanoic acid (EPA, 20:5 n-3), which might have been the reason behind the high incidence of coronary heart disease in Bahrain.
Phosphorus-doped titania powders were prepared by a sol-gel method using titanium (IV) tetrabutoxide and sodium hypophosphite as starting materials. The as-prepared products were characterized by XRD, XPS, TEM and UV-vis spectroscopy. The TiO2 powders calcined at 400°C for 5 h in an N2 atmosphere showed an anatase structure. The crystallinity of TiO2 was improved by calcination both in air and in N2 atmospheres. Furthermore, UV-vis spectroscopy analysis indicated that the absorption edge of the samples shifted to a longer wavelength after calcination. The XRD results suggested that phosphorus was doped into the crystal lattice of TiO2. The electronic states of phosphorus were determined by XPS, which indicated that the phosphorus in the prepared titania powders was in a lower oxidization state than the pentavalent oxidation state of phosphorus. Also, the photocatalytic activity was tested by observing the photodecomposition of methylene blue.