Amounts Of Sterols Research Articles

Antioxidant activity, physico-chemical properties, and bioactive compounds of Nigella sativa seeds and oil impacted by microwave processing technique

Strongly anti-oxidant and medicinal, Nigella sativa L (NS) is utilized in conventional medicine to address a range of illnesses, including gastrointestinal, inflammatory and rheumatic illnesses. This study was carried out to investigate the effects of microwave processing on the physico-chemical properties of Moroccan-grown Nigella sativa seeds and oils, as well as to investigate the antioxidant qualities of black cumin oils under conditions of accelerated oxidation. The study's specific goal was to ascertain the effects of varying microwave power levels (500 and 750 W) and roasting times (5, 10, and 15 min) on the black cumin oils' quality indices, fatty acid and sterol content, carotenoid and chlorophyll levels, mineral profile, tocopherol amount, and overall antioxidant activity. To this end, the seeds of black cumin were roasted at two power levels (500 and 750 W) and for three different periods (5, 10, and 15 min) in a microwave oven. The obtained results show that the duration and the processing power did not significantly influence the amount of sterols and fatty acids. In contrast, the quality indices, physico-chemical properties, carotenoid and chlorophyll contents, mineral profile, and tocopherol amount were influenced by the microwave processing. A significant decline in the antioxidant activity was recorded from 45.01 ± 0.81 % (unroasted cumin seeds) to 4.32 ± 0.91 % (750 W/5 min). Based on these findings, the black cumin oil preparations should be handled carefully and the oil must be protected once extracted. The stability and preservation of antioxidants are crucial steps against pro-oxidant and inflammatory conditions that could favour cellular senescence and accelerate aging processes.

Lipid Quality Changes in French Fries, Chicken Croquettes, and Chicken Nuggets Fried with High-Linoleic and High-Oleic Sunflower Oils in Domestic Deep Fryers.

The quality of fried products greatly depends on the changes occurring during frying. The purpose of this work was to study the lipid quality changes taking place in selected frozen foods after domestic deep-frying. Conventional, high-linoleic sunflower oil (HLSO) and high-oleic sunflower oil (HOSO) were used, and the frozen foods selected were French fries, croquettes, and nuggets. The foods were fried in domestic fryers under discontinuous conditions. Analyses included fatty acid composition, sterols, tocopherols, squalene, and lipid alteration levels. In all fried foods, the content of lipids increased after frying, which is consistent with previous findings. However, the lipid exchange between the food and the oil greatly depended on the food characteristics. Specifically, the levels of frying oil in the food lipids were about 90, 40, and 58% for French fries, croquettes, and nuggets, respectively. The main results obtained showed that lipid alteration levels considerably decreased and amounts of sterols and tocopherols significantly increased in French fries' lipids after frying. In both chicken products, croquettes and nuggets, the best quality improvement observed was a significant decrease in cholesterol in food lipids due to the lipid exchange. Overall, frying with HLSO and HOSO improved the quality and nutritional properties of all products tested.

Phytochemical characterization and nutritional value of vegetable oils from ripe berries of Schinus terebinthifolia raddi and Schinus molle L., through extraction methods

The aims of this study are the phytochemical exploration and food valorization of Schinus molle L. (S. molle) and Schinus terebinthifolia Raddi (S. terebinthifolia) from the Rabat, Morocco. Gas chromatography (GC) and high-performance liquid chromatography (HPLC) were used to analyze the chemical composition of the oils extracted from both species by soxhlet and maceration. Moreover, physicochemical characteristics such as lipid quality indexes such as thrombogenic index (TI), atherogenic index (AI), oxidation susceptibility (OS), and calculated oxidability (Cox) were determined. These characteristics included percentage acidity, peroxide, saponification, iodine, specific extinction values, chlorophyll, and carotenoid pigments. As results, the oil yields varied from 7% (S. molle) to 13% (S. terebinthifolia). In addition, unsaturated fatty acids represented the major fraction for S. terebinthifolia (79%) and S. molle (81%). However, S. terebinthifolia contains more saturated fatty acids (20%) than S. molle (16%) with a predominance of linoleic acid (59.53% and 55%, C18,2), oleic acid (19.29% and 21.69%, C18,1), and palmitic acid (12.56% and 15.48%, C16,0) in S. molle and S. terebinthifolia, respectively. Moreover, the main sterols are β-sitosterol followed by campesterol and then Δ-5-avenasterol, while β-sitosterol varies according to the species and the extraction method. Results revealed also that campesterol is influenced by the extraction results in a content of 179.66 mg/kg (soxhlet) and 63.48 mg/kg (maceration) for S. molle, while S. terebinthifolia yeilds concentrations of 170 mg/kg and 138 mg/kg, then Δ-5-avenasterol, which present with (117 mg/kg and 136 mg/kg), (34 mg/kg and 80 mg/kg) of the total amount of sterols for the oils extracted by soxhlet and maceration, respectively. In addition, there are favorable physicochemical properties for all oils, such as chlorophylls (0.4 to 0.8 mg/kg) and carotenoids (0.7 to 2 mg/kg). However, further investigations are needed to determine other chemical compounds of both extracts as well as to evaluate their biological and health benefits.

Sterol Migration during Rotational Frying of Food Products in Modified Rapeseed and Soybean Oils.

This study explores the impact of rotational frying of three different food products on degradation of sterols, as well as their migration between frying oils and food. The research addresses a gap in the existing literature, which primarily focuses on changes in fat during the frying of single food items, providing limited information on the interaction of sterols from the frying medium with those from the food product. The frying was conducted at 185 ± 5 °C for up to 10 days where French fries, battered chicken, and fish sticks were fried in succession. The sterol content was determined by Gas Chromatography. This research is the first to highlight the influence of the type of oil on sterol degradation in both oils and food. Notably, sterols were found to be most stable when food products were fried in high-oleic low-linolenic rapeseed oil (HOLLRO). High-oleic soybean oil (HOSO) exhibited higher sterol degradation than high-oleic rapeseed oil (HORO). It was proven that cholesterol from fried chicken and fish sticks did not transfer to the fried oils or French fries. Despite initially having the highest sterol content in fish, the lowest sterol amount was recorded in fried fish, suggesting rapid degradation, possibly due to prefrying in oil with a high sterol content, regardless of the medium used.

Human Sterols Are Overproduced, Stored and Excreted in Yeasts.

Sterols exert a profound influence on numerous cellular processes, playing a crucial role in both health and disease. However, comprehending the effects of sterol dysfunction on cellular physiology is challenging. Consequently, numerous processes affected by impaired sterol biosynthesis still elude our complete understanding. In this study, we made use of yeast strains that produce cholesterol instead of ergosterol and investigated the cellular response mechanisms on the transcriptome as well as the lipid level. The exchange of ergosterol for cholesterol caused the downregulation of phosphatidylethanolamine and phosphatidylserine and upregulation of phosphatidylinositol and phosphatidylcholine biosynthesis. Additionally, a shift towards polyunsaturated fatty acids was observed. While the sphingolipid levels dropped, the total amounts of sterols and triacylglycerol increased, which resulted in 1.7-fold enlarged lipid droplets in cholesterol-producing yeast cells. In addition to internal storage, cholesterol and its precursors were excreted into the culture supernatant, most likely by the action of ABC transporters Snq2, Pdr12 and Pdr15. Overall, our results demonstrate that, similarly to mammalian cells, the production of non-native sterols and sterol precursors causes lipotoxicity in K. phaffii, mainly due to upregulated sterol biosynthesis, and they highlight the different survival and stress response mechanisms on multiple, integrative levels.

Investigation of chemical properties and bioactive compounds of oils from different pumpkin seeds (Cucurbita pepo L.) during maturation

AbstractIn this study, seed and oil yields, protein, and moisture ratios of seeds of four different types of pumpkin seed varieties, namely Palancı population, VD1sn8, and VD1sn6 hybrid varieties and commercial variety grown in Edirne conditions in 2014 and 2015. Also, this study aimed to determine the change of fatty acid, tocopherol, and sterol composition of mentioned pumpkin seed varieties in three different periods from seed formation to final harvest time. During the ripening period, it was obtained that the oil yield increased, the moisture content of pumpkin seeds decreased. In the last harvest period, the oil yield of pumpkin seed varieties was determined to be between 37.21% and 42.07%. Protein ratios of all pumpkin seed species were found to be very close to each other (37.94%–39.28%) and statistically similar (p > 0.05). In 2014 and 2015, the dominant fatty acids for all pumpkin seed varieties are 18:1 (39.49%–46.95%) and 18:2 (32.57%–39.26%). Except for these fatty acids, 16:0 varies between 10.65% and 13.60% in all varieties; 18:0 varies at a ratio of 5.70%–6.38%. It is seen that the dominant tocopherol isomer is γ‐tocopherol for all pumpkin seed species in all harvest periods. In the last harvest period in 2014 and 2015, the amounts of γ‐tocopherol constitute 99.98%–84.95% and 86.91%–89.86% of the total tocopherol, respectively. It was observed that the tocopherol composition changed during the ripening period in all pumpkin seed species (p < 0.05). In general, the amount of sterols decreased during the ripening period for all cultivars in 2014 and 2015. In order from the highest to the least, β‐sitosterol, 5,24‐stigmastadienol, campesterol, Δ‐5 avenasterol, and stigmasterol were determined as phytosterols in pumpkin seed oils. Generally, β‐sitosterol ratios in all varieties were high in the 1st harvest period, decreased slightly in the 2nd harvest period, increased again until the 3rd harvest period and reached the values in the 1st harvest period in both 2014 and 2015.

Quantitative Determination of Cholesterol Hydroxylase Specificities by GC-MS/MS in Living Mammalian Cells.

Cholesterol is oxygenated by a variety of cholesterol hydroxylases; oxysterols play diverse important roles in physiological and pathophysiological conditions by regulating several transcription factors and cell-surface receptors. Each oxysterol has distinct and overlapping functions. The expression of cholesterol hydroxylases is highly regulated, but their physiological and pathophysiological roles are not fully understood. Although the activity of cholesterol hydroxylases has been characterized biochemically using radiolabeled cholesterol as the substrate, their specificities remain to be comprehensively determined quantitatively. To better understand their roles, a highly sensitive method to measure the amount of various oxysterols synthesized by cholesterol hydroxylases in living mammalian cells is required. Our method described here, with gas chromatography coupled with tandem mass spectrometry (GC-MS/MS), can quantitatively determine a series of oxysterols endogenously synthesized by forced expression of one of the four major cholesterol hydroxylases-CH25H, CYP7A1, CYP27A1, and CYP46A1-or induction of CH25H expression by a physiological stimulus. This protocol can also simultaneously measure the amount of intermediate sterols, which serve as markers for cellular cholesterol synthesis activity. Key features • Allows measuring the amount of a variety of oxysterols synthesized endogenously by cholesterol hydroxylases using GC-MS/MS. • Comprehensive and quantitative analysis of cholesterol hydroxylase specificities in living mammalian cells. • Simultaneous quantification of intermediate sterols to assess cholesterol synthesis activity.

Impact of different harvest times on fatty acid profile, sterol, tocopherol and bioactive properties of hazelnut oil

This study was carried out to determine the effects of different harvest times of hazelnuts on their lipid profiles and bioactive compound accumulations. Tombul hazelnut cultivar was harvested at four different harvest stages, namely in PH (pre-harvest time), EH (early harvest time), NH (normal harvest time) and LH (late harvest time). According to the results of the study, oil accumulation continued up to NH but did not further increase into LH (from 49.58 to 58.54 mg/100 g). Oxidative stability indices changed positively due to decreased poly-unsaturated fatty acids (PUFA) from 9.87 to 7.70% in LH. The highest total sterol amount was reached in LH (122.32 mg/100 g). Although the change in the tocopherol content in the oil was irregular with the progression of the harvest time, its amount in the nuts increased continuously. Total carotenoid, phenolic, flavonoid, and antioxidant activity (DPPH and ABTS) peaked in EH and decreased to a minimum in LH.

A comparative analysis of phytochemical and biochemical activities of two varieties of mango seed kernels

The present research work embraces the study of moisture content, yield percentage, organoleptic properties, and phytochemical and biochemical estimation of two varieties of mango seed kernel using different solvents with various polarity such as n-hexane, chloroform, ethyl acetate, acetone, methanol, and aqueous. Moisture content and percentage of yield were also calculated which were more in Banganpalle variety. The qualitative phytochemical and biochemical screening indicated the presence and amount of phenol, flavonoid, tannin, quinone, oxalate, saponin, sterol, triterpene, carbohydrate, protein, and lipid. The quantitative analysis result showed that phytochemicals like phenol, flavonoids, and tannin were present in higher content in the seed kernel of Neelam as compared to Banganpalle. The results from biochemical tests showed a high content of carbohydrates, proteins, and lipids in Neelam. The present study therefore conclusively points out that the mango seed kernel is a good source of various pharmacologically active substances that make a potential antioxidant, anti-inflammatory, and other therapeutic uses.

The Fungus Beauveria bassiana Alters Amounts of Sterols, Fatty Acids, and Hydroxycinnamic Acids in Potato Solanum tuberosum

The entomopathogenic endophytic fungus Beauveria bassiana can colonize plants resulting in growth promotion and protection against phytopathogenic microorganisms. However, physiological changes in potato plants (Solanum tuberosum) during this interaction are poorly understood. In the present work, gas chromatography–mass spectrometry and high-performance liquid chromatography were used to analyze sterol, fatty acid, and phenolic acid concentrations in potato plants inoculated with B. bassiana conidia in soil. We showed an increase in amounts of stigmasterol, minor sterol compounds, and some hydroxy fatty acids in leaves after the fungal treatment. Moreover, levels of hydroxycinnamic acids, especially chlorogenic acid, were elevated in roots following the B. bassiana inoculation. We propose that these changes could have been caused by oxidative reactions, and the alterations may have resulted in growth-stimulatory and protective effects of B. bassiana on the plants.

Quantitative data of up to thirty sterols in vegetable oils and fats

Sterols are known for a plethora of 250 different structures. Between 5 and 10% of them usually occur with varying abundance ratios (~ four orders of magnitude) and total amounts (0.4–1000 mg/100 g oil) in samples. Yet, quantitative data are mostly restricted to the few major sterols which are available as reference standards. Here, we developed a gas chromatography with mass spectrometry method operated in selected ion monitoring mode (GC/MS-SIM) that enabled the quantitation of 30 (silylated) sterols although only ten were available as reference standards. This could be obtained by studying the full-scan mass spectra of these ten sterol standards and 20 additional sterols measured in seven oils. In the next step, sterols were assigned to different groups. Values for quantification were then selected on the premise that response factors were constant within a sterol group. The deviation of the response factors within one sterol group was frequently below ± 10% and otherwise about ± 11–12%. Using mean response factors for all sterols, the novel GC/MS-SIM quantification method was superior to GC/FID which was exemplarily applied to two oils. Between eight and 21 of the 30 studied sterols and pentacyclic triterpenols were detected and quantified in 18 vegetable oils and two vegetable fats. The much higher number of sterols that could be quantified resulted in higher sterol amounts and the method and data may be useful for food authentication.

A Comparative LC/MS Analysis of Jordanian Olive Stone, Fruits, Leaves, and Oils

The olive (Oleo europaea L.) may be a broadly dispersed plant that began within the Mediterranean locale. Its natural product is commonly utilized to create olive oil, table olives, and other by-products. Olives are rich in carbohydrates, vitamins, and minerals. Most olive items and the dietary composition of olive oil centering on fatty acids, phenolic compounds, and other cancer prevention agents are changed in numerous parts of olive plants. The most chemical constituents important to the natural movement of olive oil were inspected. Fluid-chromatography–mass spectrometry(LC/MS) investigation uncovered more than 50 major phenolic compounds among which oleuropein, hydroxytyrosol apigenin 7-O-glucoside, tyrosol, catechin, and vanillic corrosive were recognized. Olive clears out, wealthy in carotenoids and chlorophyll, the olive stone and seed are vital products produced within the olive oil extraction, as a lingo cellulosic fabric, the hemicellulose, cellulose, and lignin are the most components of olive stone as well as protein, fat, phenols, free sugars, and polyols composition. Both lipophilic and hydrophilic phenolics are conveyed in olive natural products. The most lipophilic phenols are cresols whereas the major hydrophilic phenols incorporate phenolic acids, phenolic alcohols, flavonoids, and secoiridoids; they are shown in nearly all parts of the plant, but their nature and concentration shift incredibly between the tissues. Olive oil is composed primarily of triacylglycerols (triglycerides or fats) and contains little amounts of free greasy acids (FFA), glycerol, phosphatides, shades, flavor compounds, sterols, and minuscule bits of olive. Olive stones have a most noteworthy sum of rutin. Luteolin appeared the most noteworthy sum in takes off, while the least level was found in oils, tall concentrations of tyrosol, vanillic, and caffeic corrosive, and vanillin was found in stones. In common, rutin and luteolin 7-O-glucoside were the two fundamental flavonoids identified in all parts.

Impact of development periods on chemical properties and bioactive components of safflower (Carthamus tinctorius L.) varieties

AbstractThis study aimed to determine the chemical properties (fatty acid composition, oil content, sterol and tocopherol compositions) of the oils extracted from the seeds of safflower (Dinçer, Remzibey, Balci, Linas, Yenice, Olas) varieties harvested in different periods from flowering to ripening period. In parallel with the increase of harvest time, the humidity rate decreased, while the oil ratios increased. It was determined that palmitic (16:0) and stearic (18:0) acids, which are significant saturated fatty acids, and oleic (18:1) and linoleic (18:2) acids, which are unsaturated fatty acids, are quite high in the oils of all safflower varieties. These fatty acids showed significant changes from the first harvest to the last harvest. The total saturated fatty acid ratios decreased, while the amount of unsaturated fatty acids increased as the maturation progressed. The first and latest harvest samples of Dinçer, Remzibey, Balcı, Linas, Yenice, Olas cultivars were selected and their sterol and tocopherol compositions were examined. The highest level of sterol in all cultivars was β‐sitosterol and the amount of sterols decreased towards full maturity. It was determined that α‐tocopherol was the dominant tocopherol found in the safflower oils and the amount of tocopherol increased towards full maturity.

Whey and post-frying oil as substrates in the process of microbial lipids obtaining: a value-added product with nutritional benefits

AbstractYarrowia lipolytica has found many biotechnological applications. The species has a number of regulatory mechanisms to maintain cellular homeostasis, enabling biomass growth in complex media. The aim of this study was to evaluate the use of Y. lipolytica yeast as a platform for the simultaneous management of several industrial by-products and the production of microbial lipids with application potential in the chemical and food industries. Batch cultures of KKP 379 strain were conducted in media with post-frying rapeseed oil (PFO) and a by-product of curd cheese production—acid whey. To evaluate the potential of Yarrowia as a nutraceutical, quantitative and qualitative analyses of microbial sterols were carried out along with an assessment of the biomass mineral composition. It was indicated that the composition and content of sterols varied depending on the phase of cell growth in batch culture. During culture in medium with 20% (v/v) whey and 50 g/L PFO, the cellular lipid content reached 39% (w/w). The highest amount of sterols per dry biomass (7.38 mg/g) and cellular lipids (21.08 mg/g) was recorded after 38 h of culture. The dominant was ergosterol 12.10 mg/g (57%). In addition, the composition of carbon and nitrogen sources in the medium affected the content of selected elements in biomass, indicating that substrate modification can be a tool for manipulating the composition of yeast cells. The results of the study showed that the selection of waste substrates is an important factor in regulation of the cellular lipid accumulation efficiency, as well as the content of certain sterols.

Influence of Cryogenic Grinding on the Nutritional and Antinutritional Components of Rapeseed Cake

We investigated the influence of cryogenic grinding on the quality of rapeseed cake. Rapeseed cake is a good source of valuable proteins (30%) and oil (14%), with a balanced fatty acid composition and a fair amount of sterols, which may reduce the risk of cardiovascular diseases. However, the presence of antinutritive compounds prevents its use as a food source. Grinding under cryogenic conditions is much more efficient than grinding at room temperature in terms of particle size reduction. The additional cryogenic grinding of the cake had little effect on the nutritional components, as phytosterols and soluble dietary fiber increased slightly. It had no effect on insoluble dietary fiber, polyphenols, and tannins. Prolonged grinding time, both at room and subzero temperatures, reduced the total amount of glucosinolates by 34 and 43%, respectively. However, the reduction in undesirable components is not sufficient to use cryogenic grinding as the sole treatment for the cake, but it could be a good pretreatment for chemical or biological treatments.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid Lα phase transition for Tm = 34.5 °C and formed facetted spherical sphingosomes below Tm. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered Lo phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

Extraction and Quantitation of Phytosterols from Edible Brown Seaweeds: Optimization, Validation, and Application.

Brown seaweeds are known as important marine food sources, from which phytosterols have been recognized as functional food components with multiple health-beneficial effects. However, studies on phytosterol extraction and quantitation from edible brown seaweeds are limited. In the present work, extraction methods for seaweed phytosterols were compared and optimized by one-factor-at-one-time method and response surface methodology. Moreover, the quantitation method of total sterols and major sterol components, including fucosterol, saringosterol, and ostreasterol, was established and validated using 1H NMR. Furthermore, the developed extraction and determination methods were applied to investigate three common edible seaweeds from Japan (Hijiki, Wakame, and Kombu). As a result, the finally optimized conditions were ultrasound-assisted extraction with CHCl3-MeOH 2:3 for 15 min followed by saponification with 1.65 mL of 1.85 M KOH for 14.5 h. Based on the developed methods, phytosterols in three seaweeds were compared, and Hijiki showed an abundant total sterol amount (2.601 ± 0.171 mg/g DW), significantly higher than Wakame (1.845 ± 0.137 mg/g DW) and Kombu (1.171 ± 0.243 mg/g DW). Notably, the composition of the sterol components varied in different seaweeds. These findings might help the nutritional investigation and functional food development concerning phytosterols from seaweeds.

Effect of extraction process on quality of oil from Asphodelus tenuifolius seeds

In this study, Asphodelus tenuifolius (ATO) seeds oils were extracted by three different extraction methods, namely Soxhlet extraction (SE), microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE). The physicochemical properties, fatty acids, sterols, tocols, total phenol content and antioxidant activity of ATO seed were examined and compared. The best extraction yield was from SE (21.97 ± 0.01%), followed by MAE (19.28 ± 0.13%) while that of UAE was the lowest (16.5 ± 0.1%). Analysis of the chemical composition of these oils showed that linoleic acid and β-sitosterol were the main fatty acid and sterol compounds, respectively. A large amount of fatty acids and sterols were not significantly affected by the three extraction methods. Nevertheless, the tocols, the total phenols contents and the antioxidant power showed a variation between these three extracted oils. Based on these results, it was found that this specie has great potential for industrial use.

Sterols Content of Fruiting Bodies of Medicinal Artist's Bracket Mushroom Ganoderma applanatum (Agaricomycetes) Collected in Armenia.

The qualitative analysis of hexane extracts obtained from different trama layers (WT, T1-T4) of dried fruiting bodies of medicinal bracket fungus Ganoderma applanatum collected in the Tavoush region of North-East Armenia was performed by GC-MS analysis. Three sterols [(7.22-ergostadienon, ergosterol and ergosta-14.22-diene-3-ol (3β, 5α, 22E)] have been identified. The results have shown that the content and ratio of sterols differ in analyzed trama samples. The highest amount of sterols was detected in middle parts of T2 and T3 layers, while content of sterols gradually decreased to the upper cortical (T4) and lower hymenial (T1) layers. The chromatographic profiles of identified compounds indicate that different sterols dominated in each layer: 7.22-ergostadienon in T4, ergosterol in T3, T2, and T1. The average weight loss of analyzed trama samples during six days of drying was about 40 wt.% (37.0-43.49 wt.%) of the total weight of basidiome, which decreased up to 5 wt.% in the next two days. The complete extraction of sterols lasted six days. Its further prolongation leads to stationary phase without an increase in the amount of extracted sterols.

Fatty Acid and Sterol Compositions of Turkish Monovarietal Olive Oils with Regard to Olive Ripening.

This study was conducted in crop season of 2018 and the olive fruits from three Turkish varieties Saurani, Karamani and Halhalı under the same pedoclimatic conditions (with no irrigation and no fertilization) were assessed. Oil content, fatty acid, and sterol compositions of three monovarietal 'Halhalı', 'Karamani', and 'Saurani' virgin olive oils were examined at green, spotted and ripe olives. The oil content of olives ranges between 23.77-34.77% and the highest oil yield was observed in the ripe Karamani variety. In terms of fatty acids, the lowest oleic acid values were found in the ripe period of Karamani variety (59.78%), and the highest oleic acid values in the green period of Halhalı variety (69.97%). The oleic and palmitic acid contents decreased, while linoleic and stearic acid contents increased with olive ripening. Total sterol amounts of olive oils varied between 946-1782 mg/kg and showed a significant increase with ripening (p < 0.05). The highest β-sitosterol amount was detected in the green period of Saurani variety (91.66%), and the lowest β-sitosterol amount in the spotted period of Halhalı variety (86.16%). The highest ∆5-avenasterol amounts were detected in the ripe period of Saurani variety (6.54%), the lowest ∆5-avenasterol amounts were detected in the green period of Halhalı variety (2.36%). Total β-sitosterol, stigmasterol and erythrodiol+uvaol contents of olive oils are changed with ripening. Accordingly, these results showed that fatty acid and sterol compositions can be used as indicators of variety and ripening degree among monovarietal virgin olive oils.