Total Sterol Content Research Articles

Effects of different drying methods on the extraction rate and qualities of oils from demucilaged flaxseed

ABSTRACTEffects of different drying methods, i.e., oven drying, freeze drying, vacuum drying, and microwave drying, on the extraction rate and qualities of oil extracted from demucilaged flaxseed were investigated. The results show that microwave drying and freeze drying have higher extraction rate and yield (46.36 and 46.16% vs. 33.90%) of oil compared with native flaxseed. The oil extracted from dried flaxseed, especially the one freeze dried, had higher peroxide value (21.63 vs. 6.15 meq/kg) and specific ultraviolet extinction at 232 nm (4.56 vs. 3.67) and 268 nm (1.23 vs. 1.12), as well as a shorter induction time (1.8 vs. 3.3 h) than the one from native sample. Demucilaging and drying have no significant effect on fatty acid composition of flaxseed oil. However, these processes increased the content of total phenols and total sterols while reduced the content of chlorophyll and carotenoid pigment. In addition, the oil extracted from vacuum dried flaxseed contained more tocols when compared with native sample (447.29 vs. 370.99 mg/kg).

Quantification of sterols and fatty acids of extra virgin olive oils by FT-NIR spectroscopy and multivariate statistical analyses

In this study FT-NIR spectra of 73 extra virgin olive oil (EVOO) samples obtained from 21 different cultivars and 4 geographic regions were used to develop partial least squares regression (PLS-R) models for the rapid quantification of sterols for the first time in the literature. The results of the model validation showed that the total sterol content of the EVOO samples could be predicted with good prediction ability (Rp2 = 0.839, RMSEP = 192 mg/kg, RPD = 2.64). However, the prediction models for the individual sterol forms performed poorly. Except for heptadecanoic and eicosenic acids, models with good prediction ability could be established for the quantification of the major fatty acids found in EVOOs with Rp2 and RPD values ranging between 0.716-0.997 and 2.02–17.6, respectively. Even better model performances were obtained when fatty acids were grouped according to their unsaturation degree as SFA (Rp2 = 0.998, RMSEP = 0.102%, RPD = 21.8), MUFA (Rp2 = 0.997, RMSEP = 0.255%, RPD = 18.7) and PUFA (Rp2 = 0.998, RMSEP = 0.147%, RPD = 25.1).

Effect of gamma irradiation on the total antioxidant capacity and sterols contents in Kaissy variety extra virgin olive oil

Effect of gamma irradiation on the total antioxidant capacity and sterols contents in Kaissy variety extra virgin olive oil

Sterols in human milk during lactation: bioaccessibility and estimated intakes.

Human milk (HM) is the exclusive food during the first 4-6 months of an infant's life. Breastfeeding has been related to significant health benefits for infants, and hence it is of interest to study the bioactive compounds present in HM, such as sterols (cholesterol being the most abundant). The aim of this study was to determine the contents of sterols (cholesterol, desmosterol, lathosterol, lanosterol, campesterol, stigmasterol and β-sitosterol) in 10 pools of colostrum, transitional milk, and 1, 3 and 6 month HM obtained from Spanish volunteers from two different geographical areas (coastal and central) and to estimate the intake and bioaccessibility (BA) of sterols in order to ascertain the fate of sterols after digestion. The results showed that the total sterol contents decreased to half the initial level during lactation (24-11 mg per 100 mL) and was significantly higher in samples from the coastal area. Total and animal sterol intakes were between 200 and 400 times higher than plant sterol intakes and were significantly higher in samples from the coastal area. However, no statistically significant differences were found in cholesterol and plant sterol intakes between areas. The BA of total sterols ranged from 45% to 69% and was higher in the first month, which coinciding with the highest fat content of milk. In conclusion, the sterol content varies depending on the lactation stage and the geographical area, and the BA of sterols can be positively affected by a higher lipid content. All these data may contribute to the development of infant formulas that are more similar to HM in terms of composition and behaviour after digestion, according to the lactation stage involved.

Fortification of refined soybean oil by hull oil of two Iranian wild pistachios: Improving thermal stability during frying process

ABSTRACTIn this research, various concentrations of Kolkhoung (Pistacia khinjuk) hull oil (KHO), Beneh (Pistacia atlantica) hull oil (BHO), and Sesame (Sesamum indicume L. cv. Dezful) seed oil (1%, 2%, 4%, and 6%) as natural antioxidants were added to refined soybean oil (RSO) and antioxidant effect of these compounds was compared with that of tert-butyl hydroquinone (TBHQ) during 32 h frying process at 180°C. For this purpose, variation of acid value (AV), conjugated diene value (CDV), carbonyl value (CV), total polar compounds, and total tocol (TT) and total sterol contents of RSO was monitored during frying process. Results of oxidative stability assays revealed that 4%KHO had the best antioxidant effect which was fairly equal to that of TBHQ, followed by 4%BHO. It should be mentioned that in contrast to TBHQ, KHO and BHO are not pure antioxidant. The remarkable antioxidant effect of KHO and BHO during thermal process was due to high tocotrienol content and presence of suitable amount of Δ-7-avenasterol and Δ-5-avenasterol, respectively [TT content of KHO (2041 mg/kg) much higher than that of ordinary edible oils and 92.7% of TT content in KHO is formed by tocotrienols]. Antioxidant activity of Δ-7-avenasterol and Δ-5-avenasterol and tocotrienols during frying process was attributed to formation of stabilized tertiary alkyl radicals. These radicals cut down radical chains formed during frying process.

Dark conditions enhance aluminum tolerance in several rice cultivars via multiple modulations of membrane sterols.

Aluminum-sensitive rice (Oryza sativa L.) cultivars showed increased Al tolerance under dark conditions, because less Al accumulated in the root tips (1 cm) under dark than under light conditions. Under dark conditions, the root tip concentration of total sterols, which generally reduce plasma membrane permeabilization, was higher in the most Al-sensitive japonica cultivar, Koshihikari (Ko), than in the most Al-tolerant cultivar, Rikuu-132 (R132), but the phospholipid content did not differ between the two. The Al treatment increased the proportion of stigmasterol (which has no ability to reduce membrane permeabilization) out of total sterols similarly in both cultivars under light conditions, but it decreased more in Ko under dark conditions. The carotenoid content in the root tip of Al-treated Ko was significantly lower under dark than under light conditions, indicating that isopentenyl diphosphate transport from the cytosol to plastids was decreased under dark conditions. HMG2 and HMG3 (encoding the key sterol biosynthetic enzyme 3-hydroxy-3-methylglutaryl CoA reductase) transcript levels in the root tips were enhanced under dark conditions. We suggest that the following mechanisms contribute to the increase in Al tolerance under dark conditions: inhibition of stigmasterol formation to retain membrane integrity; greater partitioning of isopentenyl diphosphate for sterol biosynthesis; and enhanced expression of HMGs to increase sterol biosynthesis.

Early diagenetic alterations of sterol biomarkers during particle settling and burial in polluted and pristine areas of the Rio de la Plata Basin

Sources and diagenetic alterations of sterol markers were studied in settling material and sediments near the Buenos Aires main sewer (BA), and at a relatively non-polluted northern site at the Uruguay River (N). Vertical particle fluxes were 7-times higher at BA relative to N (34 ± 24 vs 4.6 ± 3.6 mg/cm2/day; mean ± standard deviation), increasing during rainy months. Total sterol contents were consistently higher at BA, both in settling material (7140 ± 7905 vs 41 ± 47 μg/g at N) and sediments (708 ± 454 vs 1.9 ± 0.18 μg/g). This difference was further amplified in the vertical flux of sterols (116 ± 168 vs 0.070 ± 0.13 mg/cm2/year). At BA, sterol composition of settling material and sediments was dominated by fecal sterols (75–77%), with extreme coprostanol concentrations (3.6 ± 4.8 vs 0.35 ± 0.28 mg/g at N) which are similar to sewage sludge. In contrast, at N the sterol profile was dominated by plant sterols (57–64%), mainly sitosterol, stigmasterol and campesterol. At BA the discharge of fresh sewage was confirmed by the high coprostanol/(coprostanol + epicoprostanol) ratio. At N, the overwhelming dominance of plant sterols over herbivore fecal sterols was reflected by the high sitosterol/(sitosterol + 24-ethylcoprostanol) ratio and the low coprostanol/(coprostanol + 24-ethylcoprostanol) ratio. The coprostanol/(coprostanol + epicoprostanol) and cholesterol/(cholesterol + cholestanol) ratios were lower in sediments than in settling material, reflecting the sterol degradation at the sediment surface. The accumulation efficiencies, calculated as the difference between trap fluxes and sediment inventories, were 2–7 times higher at BA reflecting strong vertical fluxes and enhanced preservation under anoxic conditions. During diagenetic processes, epicoprostanol (partially produced in situ), cholestanol and plant sterols were the best-preserved sterols, while cholesterol was the most labile during burial.

In vivo pharmacokinetic interaction by ethanolic extract of Gymnema sylvestre with CYP2C9 (Tolbutamide), CYP3A4 (Amlodipine) and CYP1A2 (Phenacetin) in rats

Gymnema sylvestre (GS) is a medicinal herb used for diabetes mellitus (DM). Herbs are gaining popularity as medicines in DM for its safety purpose. The aim of the present study was to evaluate in vivo pharmacokinetic (PK) interaction between allopathic drugs tolbutamide (TOLBU), amlodipine (AMLO), and phenacetin (PHENA) at low (L) and high (H) doses with ethanolic extract (EL) from GS. EL was extracted and subjected to TLC, total triterpenoid content (19.76 ± 0.02 W/W) and sterol content (0.1837 ± 0.0046 W/W) estimation followed by identification of phytoconstituents using HRLC-MS and GC-MS. PK interaction study with CYP2C9, CYP3A4 and CYP1A2 enzymes were assessed using TOLBU, AMLO and PHENA respectively to index cytochrome (CYP) mediated interaction in rats after concomitant administration of EL extract (400 mg/kg) from GS for 7 days. The rats were divided into four groups for each PK study where, group I and II were positive control for low and high dose of test drugs (CYP substrates) while group II and IV were orally administered EL. The PK study result of PHENA indicated that area under the plasma concentration–time curve (AUC0-24) was significantly (P < 0.0001) increased by 1.4 (L) and 1.3–fold (H), plasma concentration (Cmax) was significantly (P < 0.001) increased by 1.6 (L) and 1.4–fold (H). Whereas for TOLBU; clearance rate (CL) was significantly (P < 0.0001) decreased by 2.4 (L) and 2.3-fold (H), Cmax, was significantly (P < 0.001) decreased by 26.5% (L) and 50.4% (H) and AUC0-24 was significantly (P < 0.0001) decreased by 59.8% (L) and 57.5% (H). Thus, EL is seen to be interacting with CYP1A2 by inhibiting its metabolic activity. HRLC-MS and GC-MS helped identify the presence of gymnemic acid (GA), triterpenoids and steroids in EL which could be the reason for PK interaction of CYP1A2 and CYP2C9. Also, in silico structure based site of metabolism study showed Fe accessibility and intrinsic activity for GA-IV, GA-VI, GA-VII and GA-X with CYP2C9. PK parameters of AMLO were not significantly affected by pre-treatment of EL. Thereby our findings indicate that co-administration of GS with drugs that are metabolized by CYP2C9 and CYP1A2 could lead to potential HDI.

Antioxidant activity, sterol and fatty acid compositions of Turkish olive oils as an indicator of variety and ripening degree.

This study was carried out to determine the effect of three ripening stages (green, spotted and ripe) on fatty acid, sterol composition and antioxidant activity of olive oils from three olive varieties (Sarı Hasebi, Gemlik and Halhalı) widely grown in the eastern Mediterranean region of Turkey. The variety had a significant effect on the fatty acids, sterols and total phenolic content. Halhalı oil had the lowest oleic acid content (67.28%), while Sarı Hasebi oil had the highest (75.61%). Total phenolic content varied between 163.02mg GAE/kg oil and 749.28mg GAE/kg oil. Halhalı oil showed the highest antioxidant activity (IC50=66µg/ml) whereas Sarı Hasebi oil showed the lowest one (IC50=2617µg/ml). The total content of sterols in olive oils ranged from 358mg/kg in Sarı Hasebi to 1092.33mg/kg in Halhalı. The β-sitosterol content of olive oils varied between 80.72 (Sarı Hasebi) and 87.81% (Halhalı). ∆-5-avenasterol content ranged between 3.34 (Halhalı) and 7.30% (Gemlik). Variety and ripening degree significantly affected the β-sitosterol, ∆-5-avenasterol and erythrodiol+uvaol contents of oils. Finally, these results showed that sterol and fatty acid compositions can be used as indicators of variety and ripening degree among virgin olive oils.

Dietary Plant Sterols Supplementation Increases In Vivo Nitrite and Nitrate Production in Healthy Adults: A Randomized, Controlled Study.

A randomized, double‐blinded, placebo‐controlled and crossover study was conducted to simultaneously measure the effects, 3 h after consumption and after 4‐wk daily exposure to plant sterols‐enriched food product, on in vivo nitrite and nitrate production in healthy adults. Eighteen healthy participants (67% female, 35.3 [mean] ± 9.5 [SD] years, mean body mass index 22.8 kg/m2) received 2 soy milk (20 g) treatments daily: placebo and one containing 2.0 g free plant sterols equivalent of their palmityl esters (β‐sitosterol, 55%; campesterol, 29%; and stigmasterol, 23%). Nitrite and nitrate concentrations were measured in the blood plasma and urine, using stable isotope‐labeled gas chromatography‐mass spectrometry. L‐arginine and asymmetric dimethylarginine concentrations in blood serum were measured using commercially available enzyme immunoassays. Nitrite and nitrate concentrations in blood plasma (nitrite 5.83 ± 0.50 vs. 4.52 ± 0.27; nitrate 15.78 ± 0.96 vs. 13.43 ± 0.81 μmol/L) and urine (nitrite 1.12 ± 0.22 vs. 0.92 ± 0.36, nitrate 12.23 ± 1.15 vs. 9.71 ± 2.04 μmol/L) were significantly elevated after 4‐wk plant sterols supplementation Placebo and 3‐h treatments did not affect the blood plasma and urinary concentrations of nitrite and nitrate. Circulating levels of L‐arginine and asymmetric dimethylarginine were unchanged in the placebo and treatment arms. Total plant sterols, β‐Sitosterol, campesterol, and stigmasterol concentrations were significantly elevated after 4‐wk treatments compared to the placebo and 3‐h treatments. Blood plasma nitrite and nitrate concentrations correlated significantly with the plasma total and specific plant sterol concentrations. Our results suggest that dietary plant sterols, in the combination used, can upregulate nitrite, and nitrate production in vivo.

Tomato UDP-Glucose Sterol Glycosyltransferases: A Family of Developmental and Stress Regulated Genes that Encode Cytosolic and Membrane-Associated Forms of the Enzyme.

Sterol glycosyltransferases (SGTs) catalyze the glycosylation of the free hydroxyl group at C-3 position of sterols to produce sterol glycosides. Glycosylated sterols and free sterols are primarily located in cell membranes where in combination with other membrane-bound lipids play a key role in modulating their properties and functioning. In contrast to most plant species, those of the genus Solanum contain very high levels of glycosylated sterols, which in the case of tomato may account for more than 85% of the total sterol content. In this study, we report the identification and functional characterization of the four members of the tomato (Solanum lycopersicum cv. Micro-Tom) SGT gene family. Expression of recombinant SlSGT proteins in E. coli cells and N. benthamiana leaves demonstrated the ability of the four enzymes to glycosylate different sterol species including cholesterol, brassicasterol, campesterol, stigmasterol, and β-sitosterol, which is consistent with the occurrence in their primary structure of the putative steroid-binding domain found in steroid UDP-glucuronosyltransferases and the UDP-sugar binding domain characteristic for a superfamily of nucleoside diphosphosugar glycosyltransferases. Subcellular localization studies based on fluorescence recovery after photobleaching and cell fractionation analyses revealed that the four tomato SGTs, like the Arabidopsis SGTs UGT80A2 and UGT80B1, localize into the cytosol and the PM, although there are clear differences in their relative distribution between these two cell fractions. The SlSGT genes have specialized but still largely overlapping expression patterns in different organs of tomato plants and throughout the different stages of fruit development and ripening. Moreover, they are differentially regulated in response to biotic and abiotic stress conditions. SlSGT4 expression increases markedly in response to osmotic, salt, and cold stress, as well as upon treatment with abscisic acid and methyl jasmonate. Stress-induced SlSGT2 expression largely parallels that of SlSGT4. On the contrary, SlSGT1 and SlSGT3 expression remains almost unaltered under the tested stress conditions. Overall, this study contributes to broaden the current knowledge on plant SGTs and provides support to the view that tomato SGTs play overlapping but not completely redundant biological functions involved in mediating developmental and stress responses.

Hatay Zeytinyağlarının Yağ Asidi ve Sterol Kompozisyonları

In this study, sterol and fatty acid compositions with the other quality criteria (free fatty acids, peroxide value, total chlorophyll and carotenoid content) of olive oil samples obtained from Halhalı, Gemlik and Sarı Hasebi varieties through two phase mechanical method (crushing, kneading and centrifuge) was determined. Oleic, palmitic, linoleic, stearic, palmitoleic, linolenic and arachidic acids were the determined as the main fatty acids in olive oil samples. It was determined that oleic acid contents of oil samples ranged between 66.25-76.14% and Sarı Hasebi had the highest oleic acid content. Sterol and fatty acid compositions of olive oil samples showed significantly statistical differences according to varieties. It was determined that the total sterol contents of oils ranged between 1025 and 1686 mg/kg and varieties with the highest and lowest total sterol content were Gemlik and Sarı Hasebi. Apparent β-sitosterol contents (β-sitosterol, Δ-5-avenasterol, Δ-5-24-stigmastadienol, klerosterol, sitostanol) were between 92.96 and 94.63%. Varieties with the highest and lowest apparent β-sitosterol contents were oils which belong to Halhalı and Sarı Hasebi varieties respectively. β -sitosterol (83.08-88.21%), Δ-5-avenasterol (4.82-6.97%) and campesterol (2.28-3.43%) were identified as the main sterol components. Erythrodiol + uvaol contents of olive oils varied between 2.28 and 3.43% and these values were within the limits established by Turkish Food Codex.

Evaluation of in vitro and in vivo anti-urolithiatic activity of silver nanoparticles containing aqueous leaf extract of Tragia involucrata

The present investigation is focused on exploring the anti-urolithiatic potential of aqueous leaf extract of Tragia involucrata (TIA) and its silver nanoparticles (AgNPs) and to quantify the total phenol, flavonoid, terpenoid and sterol contents present in TIA. Quantification results suggested TIA to be a rich source of phenol, flavonoid and terpenoid and less of sterol content. The AgNPs were synthesized by a simple green method using aqueous extract of T. involucrata. The formation of AgNPs was confirmed through UV spectroscopy, particle size analysis, zeta potential, X-ray diffraction and transmission electron microscopy. The in vitro struvite growth inhibitory activity of the extract was performed using a single gel diffusion method. Samples incorporated with higher concentration of 2% TIA and AgNPs (200μgmL-1) exhibited potent crystal growth inhibitory activity which was further supported by the dissolution of crystals in gel medium. Calcium oxalate stone formation was induced in rats by the oral administration of ethylene glycol in water. Stone formation was assessed by increase in the levels of calcium and phosphorous in the urine and accumulation of nitrogenous substances like urea, creatinine in renal tissues and blood. Prophylactic treatment with TIA and AgNPs showed significant anti-urolithiatic activity with normalization of the mineral contents of the urine and serum samples. Histopathological analysis of the kidney of TIA- and AgNP-treated animals showed no CaOx deposits and a normal architecture of the kidney cells. We conclude that aqueous extract of T. involucrata and its AgNPs has potential for the treatment of patients with recurrent stones.

The Content and Composition of Total, Free, and Esterified Sterols of Lotus Plumule Oil by GC–MS/FID

AbstractThis study investigated the content and composition of total, free, and esterified sterols of three varieties of lotus plumule oil (Hunan lotus, Jiangxi lotus, and Fujian lotus) using GC–MS/FID. The fatty acid composition of sterol fatty acid esters (SFAE) was also analyzed and compared with that of triglycerides. Results showed that total sterol of lotus plumule oil (12.10–14.21 g/100 g) was higher than that of other plant oils (corn germ oil, 1.11 g/100 g; rapeseed oil, 0.78 g/100 g). No significant difference was found among the total sterol contents of the three types of lotus plumule oils (p &gt; 0.05). Most sterol existed in ester forms (81.8–89.1%) rather than in free forms (8.4–10.1%). β‐Sitosterol (71.4–73.4%), and campesterol (6.2–7.5%) were the predominant fractions of free sterols. β‐Sitosterol (41.3–53.7%) and ∆5‐avenasterol (27.1–31.1%) were the predominant fractions of esterified sterols, followed by campesterol (12.1–13.0%) and ∆7‐avenasterol (3.4–3.7%). Linoleic acid (63.6–65.8%), oleic acid (8.3–10.4%), and behenic acid (9.0–9.9%) were the main fatty acids of SFAE, which were different from those of triglycerides. The results from this study suggest that lotus plumule oil may be a good resource of SFAE and can be used as a supplemental ingredient in functional foods.

Correlations between Antioxidant Activity and Alkaloids and Phenols of Maca (Lepidium meyenii)

The antioxidant capacity of maca has been considered to be the basis for other bioactivities, and revealing the active antioxidant compounds would help to elucidate a variety of bioactive compounds. In this study, the correlation between the antioxidant activity of maca and secondary metabolites, including ferric reducing antioxidant potential (FRAP), hydroxyl radical scavenging ability (HRSA), lipid peroxidation inhibition ability (LPIA), total phenolic contents (TPCs), total alkaloid contents (TACs), and total sterol contents (TSCs), was investigated by measuring. Chloroform was selected to be an efficient extraction solvent for antioxidant compounds in maca by polarity fractions test. The results showed that TPC exhibited significant linear correlations (P&lt;0.05) to FRAP and LPIA, while TAC had significant linear correlations (P&lt;0.05) to FRAP, HRSA, and LPIA. These results suggested that alkaloids and phenols were the most important substances for the antioxidation of maca, of which the antioxidant effect of alkaloids seemed to be higher than that of phenols.

Platform for "Chemical Metabolic Switching" to Increase Sesquiterpene Content in Plants.

The biosynthetic pathway of cytosolic isoprenoids bifurcates after farnesyl diphosphate into sesquiterpene and triterpene pathways. "Metabolic switching" has been used to increase sesquiterpene content in plants by suppressing the competitive triterpene pathway using transgenic technology. To develop "metabolic switching" without using transgenic technology, we developed a model system of "chemical metabolic switching" using inhibitors of the competitive pathway. Arabidopsis plants that overexpress the amorpha-4,11-diene synthase gene were treated with squalestatin, a squalene synthase inhibitor, or terbinafine, a squalene epoxidase inhibitor. We then analyzed total sterol content as major triterpenes and amorpha-4,11-diene in the plant. Plants treated with squalestatin showed decreased total sterol content and increased amorpha-4,11-diene content. In contrast, plants treated with terbinafine showed decreased total sterol content, but amorpha-4,11-diene accumulation was quite low. These results suggest that inhibition of the enzyme just below the branch point is more effective than inhibition of enzymes far from the branch point for "chemical metabolic switching". In addition, the activity of 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of the cytosolic isoprenoid biosynthetic pathway, was upregulated in plants treated with squalestatin, suggesting that feedback regulation of 3-hydroxy-3-methylglutaryl-CoA reductase may contribute to amorpha-4,11-diene production. Here we demonstrated the effectiveness of "chemical metabolic switching" in plants.

Antifungal Activity of Oleuropein against Candida albicans-The In Vitro Study.

In the present study we investigated activity of oleuropein, a complex phenol present in large quantities in olive tree products, against opportunistic fungal pathogen Candida albicans. Oleuropein was found to have in vitro antifungal activity with a minimal inhibitory concentration (MIC) value of 12.5 mg·mL−1. Morphological changes in the nuclei after staining with fluorescent DNA-binding dyes revealed that apoptosis was a primary mode of cell death in the analyzed samples treated with subinhibitory concentrations of oleuropein. Our results suggest that this antifungal agent targets virulence factors essential for establishment of the fungal infection. We noticed that oleuropein modulates morphogenetic conversion and inhibits filamentation of C. albicans. The hydrophobicity assay showed that oleuropein in sub-MIC values has significantly decreased, in both aerobic and anaerobic conditions, the cellular surface hydrophobicity (CSH) of C. albicans, a factor associated with adhesion to epithelial cells. It was also demonstrated that the tested compound inhibits the activity of SAPs, cellular enzymes secreted by C. albicans, which are reported to be related to the pathogenicity of the fungi. Additionally, we detected that oleuropein causes a reduction in total sterol content in the membrane of C. albicans cells, which might be involved in the mechanism of its antifungal activity.

Comparison of Chemical Composition in Tuber aestivum Vittad. of Different Geographical Origin

Truffles are prized and nutrition-rich edible hypogeous fungi. The aim of this study was a comprehensive investigation of chemical composition of Burgundy truffle (Tuber aestivum Vittad.). We tried to answer the question: what is the impact of the environment on the truffle quality. To know the nutritional value of Burgundy truffle we compared lipids, proteins, saccharides, polyphenolics, flavonoids, total sterols, ergosterol, volatile flavour and aroma compounds content in fruit bodies of the fungus collected in three different geographical regions, i.e., Poland, Slovakia, and Italy. A comparison of the above mentioned compounds is especially interesting due to environmental and climatic differences among the studied geographical regions. Results revealed that fruit bodies of T.aestivum from Poland and Slovakia possessed nearly similar content of proteins, total sterols, and saccharides. The fruiting bodies from Italy contained significantly larger amounts of most of the investigated compounds. In turn, Polish specimens had higher content of lipids and polyphenolics than Slovak and Italian ones. We have found higher similarity of volatile compounds composition between Polish and Italian specimens than those of Polish and Slovakorigin.

ГІПОХОЛЕСТЕРОЛЕМІЧНА ДІЯ N–АЛКІЛАМІДОВАНОГО АЛЬГІНАТУ

It is known that in the process of digestion and absorption of nutrients, one of the key roles belongs to polysaccharides (among which there are alginic acid), which have the ability to increase viscosity and form a gel in the intestine. Previously, we studied the physiological effects of pectin, cellulose and their amidated derivatives that have demonstrated growth of hypocholesterolemic activity in the rats. From here, it was decided to investigate the hypocholesterolemic effect of N–alkylamidated alginate on laboratory animals. That’s why, female rats were fed according to three diets, namely the control (1) and two experimental (2 and 3), which contained cholesterol (10 g/kg) and different amounts N–alkylamidated alginate (0 and 40 g / kg, respectively), and all animals fed also palm oil. N–alkylamidated alginate significantly lowered the level of cholesterol (total and LDL) in serum and liver and of hepatic total lipids in the rats, which were on cholesterol–containing diet. In the faeces of animals that consumed N–alkylamidated alginate, it was observed increased concentrations of fat from 61 to 91 mg / g, while the concentration of cholesterol, bile acids and total sterols was not significantly changed.Hence, decrease cholesterolemia in rats (that consumed N–alkylamidated alginate) is probably based more on the removal of fat from the intestine, rather than on the interruption of enterohepatic circulation of cholesterol.

Effects of Variety, Maturation and Growing Region on Chemical Properties, Fatty Acid and Sterol Compositions of Virgin Olive Oils

AbstractChemical properties, fatty acid and sterol compositions of olive oils extracted from Gemlik and Halhalı varieties grown in Hatay and Mardin provinces in Turkey were investigated during four maturation stages. The olive oil samples were analyzed for their chemical properties such as free acidity, peroxide value, total carotenoid, total chlorophyll, total phenolic contents, antioxidant activity, fatty acid and sterol compositions. Chemical properties, fatty acids and sterol profiles of olive oil samples generally showed statistically significant differences depending on the varieties, maturation and growing areas (p &lt; 0.05). As free fatty acid contents and total phenolic contents increased, total carotenoid and chlorophyll contents decreased throughout the maturity stages. Total carotenoid and chlorophyll contents of oil samples from Mardin were higher than those of Hatay. The total phenolic compounds of olive oil samples ranged from 20.62 in Gemlik to 525.22 mg GAE/kg oil in Halhalı from Hatay. In general, the phenolic contents and antioxidant activities of olive oil samples were positively associated. Oleic acid content was the highest 71.53 % in H1 samples in Hatay. Total sterol contents were 1194.33 mg/kg in Halhalı and 2008.66 mg/kg in Gemlik from Hatay. Stigmasterol contents of oils obtained from Hatay were lower than those of Mardin. Oleic acid, palmitic acid, β‐sitosterol, ∆‐5‐avenasterol and campesterol contents fluctuated with maturation for each of variety from both growing regions. These results showed that the variety, growing area and maturation influence the chemical properties, fatty acid and sterol compositions.