Sterol Content Research Articles

Effect of different diet composition on the fat profile of two different black soldier fly larvae populations

Black soldier fly larvae (Hermetia illucens; BSFL) can transform organic wastes into nutritional biomass useful in animal feeding. The aim of this work was to study the effect of five diets (meat, fruit, vegetable substrates, a mix of them and control) on the profile of fatty acids (FAs) and sterols of BSFL. For a more exhaustive characterization of the nutritional properties, the profile of esterified FAs in the sn-2 position of the triglycerides, the most absorbed lipid component during animal digestion was evaluated. The dietary effect was estimated on two different Hermetia illucens populations (Greek − UTH and Italian − UNIPI). The diet affected all the lipid fractions examined. Regardless of diet, the fat was characterized mainly of lauric acid and other saturated FAs, which were found to be synthesized by the larvae, as it was not present in any of the five substrates. In general, UTH larvae contained a higher level of lipids (7.38 vs 2.48 g/100 g of larvae; P < 0.001) and saturated FAs (49.71 vs 36.10 g/100 g of Total Lipids; P < 0.001) and a lower percentage of monounsaturated FAs (14.74 vs 26.70 g/100 g of Total Lipids), C18:3n-3 (0.67 vs 1.13 g/100 g of Total Lipids; P < 0.001), and C18:2c9t11 (2.02 vs 2.80 g/100 g of Total Lipids; P < 0.001). Irrespective of the populations, BSFL reared on control and fruit substrates showed higher level of lipids (8.06 and 5.61 g/100 g of larvae, respectively), and saturated FA (38.99 and 71.19 g/100 g of Total Lipids, respectively), while the presence of meat increased the level of C20:4n-6, C20:5n-3 and C22:5n-3 (0.70, 0.13 and 0.45 g/100 g of Total Lipids, respectively). The results confirmed that BSFL accumulate phytosterols in their lipid fraction. The sterol profile was strongly influenced by the substrate on which the larvae were reared, with higher levels of cholesterol in the larvae of the meat group (38.55 mg/100 g of Total Lipids) and of stigmasterol and campesterol (9.04 and 15.23 mg/100 g of Total Lipids, respectively) in those of the vegetable group. The sterol content between the two populations was significantly different, with a higher percentage in UTH larvae (113.28 vs 34.03 mg/100 g of Total Lipids; P < 0.001). Finally, BSFLs showed a high plasticity of the lipid profile depending on both the substrate and the metabolism linked to the different populations. This variability allows the nutritional characteristics of the BSFL to be shaped by modifying the substrate, to adapt it to the technological and feeding needs to which the larvae are destined.

Relationship between nitrate, heavy metal, and sterols contents in Japanese agricultural soils with risk of groundwater pollution

In Japanese agricultural lands, nitrate-nitrogen contamination of soil and groundwater often occurs due to the application of livestock excrements and compost. Therefore, rural soils in Japan were sampled and analyzed for nitrate-nitrogen leaching, heavy metal content, and sterols associated with livestock excrement and compost to calculate contamination risk indicators. The results were analyzed using self-organizing maps and cluster analysis. Nitrate-nitrogen content using water extraction was detected in most of the sampled soils. In addition, many samples from areas that were already severely contaminated with nitrate-nitrogen showed particularly high concentrations. Coprostanol, an indicator of fecal contamination, was detected in more than half of the samples. The main source of nitrate-nitrogen contamination in these areas is livestock excrement and compost. Self-organization maps showed that areas with high nitrate-nitrogen contamination also corresponded to areas with high copper and zinc soil contents. The self-organization maps and cluster analysis resulted in five clusters: a nitrate-contaminated group mainly originating from livestock excrement and compost, a heavy metal-contaminated group, a general group, a nitrate-contaminated group mainly originating from chemical fertilizers, and a contaminated group with potentially hazardous substances requiring attention. Authorities and decision-makers can use the results to prioritize areas requiring remediation.

ISSR-Assisted Breeding of Excellent New Strains of Ganoderma lingzhi through Single-Spore Selfing

ISSR-Assisted Breeding of Excellent New Strains of Ganoderma lingzhi through Single-Spore Selfing

Evaluation of sterols as markers of fungal spoilage in red pepper powder

Red pepper powder (RPP) made from ground dried red pepper (Capsicum annuum L.) is prone to adulteration with fungal-spoiled RPP to gain unfair profits in Korea. This study aimed to investigate the effects of fungal infection on the ergosterol and phytosterol content of RPP and evaluate the potential of the sterol content as a marker for identifying fungal-spoiled RPP. Ergosterol was detected only in fungal-spoiled RPP and not in unspoiled RPP [<LOD (2.3 mg/kg)], making it a reliable marker for fungal spoilage. The ergosterol content [<LOQ (7.07 mg/kg)–87.4 mg/kg] in commercial RPP samples suggested contamination levels of 0.2–28.9 w/w% by fungal-spoiled RPP, depending on the fungal species. Despite elevated levels of campesterol, stigmasterol, and β-sitosterol and high stigmasterol-to-β-sitosterol ratios in fungal-spoiled RPP compared to unspoiled RPP, these parameters were not reliable markers due to natural variations of these compounds in RPP, not specific to fungal influence.

Abstract PO4-08-01: Methylsterol monooxygenase 1 (MSMO1) modulates endoplasmic reticulum stress through cholesterol metabolic reprogramming to alter chemotherapy sensitivity in breast cancer

Abstract Background Endoplasmic reticulum stress (ER stress) is a process in which cells activate unfolded protein response and other signaling pathways in response to misfolded and unfolded protein aggregation and calcium ion balance disturbance in the endoplasmic reticulum cavity. Depending on the intensity of endoplasmic reticulum stress, it can not only induce chaperone expression to play a protective effect, but also induce apoptosis independently. Metabolic reprogramming is one of the characteristics of tumor, which refers to the metabolic changes that cells make in response to various stimuli. Here, we demonstrate that methylsterol monooxygenase 1 (MSMO1) regulates cellular cholesterol metabolism and influences breast cancer susceptibility to chemotherapy by regulating the relative intracellular T-MAS content. Methods RNA-seq was performed on core needle biopsy samples from 26 patients receiving neoadjuvant chemotherapy for breast cancer to screen for genes that may influence neoadjuvant chemotherapy sensitivity. Cell proliferation, CCK8 assay and apoptosis assay were performed for MSMO1 phenotype study. Transmission electron microscopy (TEM) was conducted to visualize the structure of endoplasmic reticulum. Western Blot was used to detect the activation level of the unfolded protein response pathway. The relative content of sterols in MSMO1 knockdown cells was detected by targeted lipid mass spectrometry. AO/PI staining of breast cancer organoids was performed to verify the effect of MSMO1 metabolic substrate T-MAS on chemotherapy drug sensitivity. Results RNA-seq of core needle biopsy samples from breast cancer patients receiving neoadjuvant chemotherapy suggested that MSMO1 was highly expressed in non-pCR patients, and clinical survival data suggested that MSMO1 was associated with poor prognosis in patients with all types of breast cancer, suggesting that MSMO1 might be related to chemotherapy sensitivity of breast cancer. Phenotypic experiments revealed that MSMO1 regulates chemotherapy sensitivity of breast cancer both in vivo and in vitro. Ectopic overexpression of MSMO1 promoted cancer cell resistance to chemotherapy. To uncover the underlying mechanisms, RNA-seq of MSMO1 knock-down cells were carried out and identified that MSMO1 was associated with ER stress. TEM and western blot assay indicated that downregulation of MSMO1 expression leads to endoplasmic reticulum swelling and activation of the unfolded protein response. Considering that MSMO1 is a cholesterol metabolizing enzyme, targeted lipids mass spectrometry was performed to detect the changes in the contents of various intermediate metabolites in the cholesterol pathway, which indicated that the relative content of T-MAS, a metabolic substrate of MSMO1, was significantly up-regulated in MSMO1 knockdown cells. Then, in order to verify whether this metabolite can independently regulate ER stress, breast cancer cells were given T-MAS externally, and TEM and Western Blot analysis indicated that T-MAS could induce ER stress and activate the unfolded protein response independently. Apoptosis assay and AO/PI staining of breast cancer organoids revealed that T-MAS can improve the sensitivity of breast cancer to chemotherapy drugs. Conclusion In summary, these results shed light on the role of MSMO1 in cholesterol metabolism reprogramming, which adjust the endoplasmic reticulum stress state of cells by changing the relative content of intracellular T-MAS, and thereby influencing the sensitivity of breast cancer chemotherapy. As an intermediate metabolite of cholesterol metabolism, T-MAS has potential clinical application value of chemotherapy sensitization. Citation Format: Hengyu Ren, Liren Wangxu, Yayun Chi, Jiong Wu. Methylsterol monooxygenase 1 (MSMO1) modulates endoplasmic reticulum stress through cholesterol metabolic reprogramming to alter chemotherapy sensitivity in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-08-01.

Valorization of waste seashells for neutralization of sunflower oil

In this study, an investigation was conducted to explore the potential of utilizing calcium oxide (CaO) derived from carbonized seashells for the purpose of acid removal. Consequently, the objective of this research is to develop an alternative bio-material to be employed in the neutralization process. The CaO produced was compared to the conventional utilization of caustic (NaOH) based on various parameters related to oil quality. It was observed that the removal rates of free fatty acid content using CaO and NaOH were 61% and 85% respectively. Furthermore, it was determined that the use of CaO did not result any adverse effects on the composition of sterols and fatty acids during the neutralization process. On the contrary, the preservation of total sterol content was superior in comparison to NaOH. The neutralization loss observed with CaO was comparable to that of NaOH. Consequently, CaO demonstrates promise as an alkaline substitute for acid removal in vegetable oils. Additionally, it is well-suited for implementation under minimal process conditions, which have become increasingly popular in recent years.

Magnetic biocatalytic nanoreactors based on graphene oxide with graded reduction degrees for the enzymatic synthesis of phytosterol esters

As we know, the carriers of enzymatic nanoreactors with different amphipathy have significant influence on the interfacial enzyme activities and its performance. In this study, the magnetic graphene oxide (GO) enzyme carriers were constructed by assembling graphene oxide with different reduction degrees (rGO(x)) and polyethyleneimine (PEI) modified nano-flowery Fe3O4 into composite materials through electrostatic interactions, and x here represents the reduction reaction hours of GO. The SEM, TEM, contact angles and BET tests qualified the ideal enzyme carrier, PEI-Fe3O4-rGO(12), by adsorption-crosslinking method, the Candida rugosa lipase (CRL) was immobilized to obtain the lipase nanoreactor, PEI-Fe3O4-rGO(12)@CRL. The nano-sheet and nano-flower structures provided a larger specific surface area and suitable pore size, and the CRL had higher protein load on the carrier material (163.11 mg/g). In addition, using hydrolyzed p-nitrophenol palmitate as the model, the PEI-Fe3O4-rGO(12)@CRL can still show 76.5 % residual activity after 8 repeated uses. At the same time, the immobilized lipase showed good catalytic performance in the biosynthesis of phytosterol esters. The optimal esterification conditions were determined by single factor experiment (isooctane, sterol concentration 150 μmol/mL, alkyd molar ratio 1:2, enzyme dosage 120 mg, 26 h, 55 °C, the esterification rate was 76.24 %). Therefore, the optimal biocatalyst PEI-Fe3O4-rGO(12)@CRL may has good performance in the biosynthesis of other novel foods.

Physiological and Biochemical Alterations during the Germination of Aspergillus Niger Conidia

The provided analytical data pertains to the germination of Aspergillus niger van Tieghem spores, focusing on various components measured by dry weight. These components include sugars, organic acids, amino acids, proteins, and lipids. Additionally, indicators of spore activity, such as respiration and permeability changes, were assessed. It is noteworthy that A. niger spores do not initiate germination utilizing their internal reserves. The introduction of glucose triggers heightened oxygen consumption and an increase in the overall concentration of organic acids. The initial 3-hour germination period is characterized by an augmentation in protein synthesis, along with a reduction in free amino acid concentration, which suggests the synthesis of proteins to facilitate germination. Furthermore, changes in permeability are observed to influence the release of various substances from the germinating spores. Significant alterations occur in the concentration of free sterols and the sterol-to-lipid ratio in germinating A. niger spores. During the early stages of germination, there is extensive degradation of phospholipids, particularly phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and their lyso-derivatives. However, these phospholipids are subsequently resynthesized in the later stages of germination. Regarding nonpolar lipids in A. niger spores, they consist primarily of hydrocarbons, triglycerides, fatty acids, sterol esters, and free sterols. Notably, the content of free sterols increases while the content of hydrocarbons decreases during the germination process in A. niger spores.

Platelet proteomic profiling in sitosterolemia suggests thrombocytopenia is driven by lipid disorder and not platelet aberrations

AbstractSitosterolemia is a rare autosomal recessive genetic disorder in which patients develop hypercholesterolemia and may exhibit abnormal hematologic and/or liver test results. In this disease, dysfunction of either ABCG5 or ABCG8 results in the intestinal hyperabsorption of all sterols, including cholesterol and, more specifically, plant sterols or xenosterols, as well as in the impaired ability to excrete xenosterols into the bile. It remains unknown how and why some patients develop hematologic abnormalities. Only a few unrelated patients with hematologic abnormalities at the time of diagnosis have been reported. Here, we report on 2 unrelated pedigrees who were believed to have chronic immune thrombocytopenia as their most prominent feature. Both consanguineous families showed recessive gene variants in ABCG5, which were associated with the disease by in silico protein structure analysis and clinical segregation. Hepatosplenomegaly was absent. Thrombopoietin levels and megakaryocyte numbers in the bone marrow were normal. Metabolic analysis confirmed the presence of strongly elevated plasma levels of xenosterols. Potential platelet proteomic aberrations were longitudinally assessed following dietary restrictions combined with administration of the sterol absorption inhibitor ezetimibe. No significant effects on platelet protein content before and after the onset of treatment were demonstrated. Although we cannot exclude that lipotoxicity has a direct and platelet-specific impact in patients with sitosterolemia, our data suggest that thrombocytopenia is neither caused by a lack of megakaryocytes nor driven by proteomic aberrations in the platelets themselves.

Identification of a mechanism promoting mitochondrial sterol accumulation during myocardial ischemia-reperfusion: role of TSPO and STAR.

Hypercholesterolemia is a major risk factor for coronary artery diseases and cardiac ischemic events. Cholesterol per se could also have negative effects on the myocardium, independently from hypercholesterolemia. Previously, we reported that myocardial ischemia-reperfusion induces a deleterious build-up of mitochondrial cholesterol and oxysterols, which is potentiated by hypercholesterolemia and prevented by translocator protein (TSPO) ligands. Here, we studied the mechanism by which sterols accumulate in cardiac mitochondria and promote mitochondrial dysfunction. We performed myocardial ischemia-reperfusion in rats to evaluate mitochondrial function, TSPO, and steroidogenic acute regulatory protein (STAR) levels and the related mitochondrial concentrations of sterols. Rats were treated with the cholesterol synthesis inhibitor pravastatin or the TSPO ligand 4'-chlorodiazepam. We used Tspo deleted rats, which were phenotypically characterized. Inhibition of cholesterol synthesis reduced mitochondrial sterol accumulation and protected mitochondria during myocardial ischemia-reperfusion. We found that cardiac mitochondrial sterol accumulation is the consequence of enhanced influx of cholesterol and not of the inhibition of its mitochondrial metabolism during ischemia-reperfusion. Mitochondrial cholesterol accumulation at reperfusion was related to an increase in mitochondrial STAR but not to changes in TSPO levels. 4'-Chlorodiazepam inhibited this mechanism and prevented mitochondrial sterol accumulation and mitochondrial ischemia-reperfusion injury, underlying the close cooperation between STAR and TSPO. Conversely, Tspo deletion, which did not alter cardiac phenotype, abolished the effects of 4'-chlorodiazepam. This study reveals a novel mitochondrial interaction between TSPO and STAR to promote cholesterol and deleterious sterol mitochondrial accumulation during myocardial ischemia-reperfusion. This interaction regulates mitochondrial homeostasis and plays a key role during mitochondrial injury.

Assessing the influence of Secoisolariciresinol diglucoside multi‐antioxidants on flaxseed oil's oxidative stability

AbstractTo increase the oxidative stability of flaxseed oil (FSO), combinations of two synergists (vitamin C, citric acid) and five distinct antioxidants (SDG (Secoisolariciresinol diglucoside), tea polyphenol (TP), resveratrol (RE), caffeic acid (CA), and vitamin E (VE)) were assessed. Based on the accelerated oxidation reaction at 65°C, the antioxidant effect was assessed for changes in the shelf‐life, fatty acid composition, peroxide value (POV), volatile and sterol contents of FSO. The SDG multi‐antioxidant combination, which included 0.01% SDG, 0.01% TP, and 0.02% vitamin C, demonstrated the strongest antioxidative qualities, according to the data; the POV of FSO dropped by 57.5% as compared to the blank group. Additionally, the SDG multi‐antioxidant combination outperformed 0.02% TBHQ (tertiary butylhydroquinone), increased the shelf‐life of FSO from 295 to 761 days, and postponed the deterioration of sterols and unsaturated fatty acids. Furthermore, the production of ketones and the degradation of esters and acids were diminished. In summary, the combination of SDG‐TP and vitamin C as antioxidants can be an effective natural alternative to artificial antioxidants to extend the shelf‐life of FSO.Practical Applications: Flaxseed oil utilizing multi‐antioxidant combinations has a wide range of practical applications. Multi‐antioxidant combination of flaxseed oil helps prevent cell damage and slows down the aging process. Antioxidant‐rich oils have numerous health benefits such as reducing inflammation, promoting heart health and improving digestive health. Multi‐antioxidant combination flaxseed oil is versatile and a valuable natural product that can be used in all aspects of daily life to improve overall health, It can provide a theoretical reference for the selection of antioxidants to improve the oxidative stability of flaxseed oil, provide a theoretical basis for the replacement of artificial antioxidants, and also provide certain technical support for the industrial application of flaxseed oil.

Effect of replacing olive oil with oil blends on physicochemical and sensory properties of taralli

SummaryEdible fats and oils are usually considered in the production of bakery products for technological and sensory reasons, but the nutritional and economic aspects and the oxidative stability of the final product must also be taken into account. Four different oil blends (high oleic sunflower oil, 87.5% extra virgin olive oil + 12.5% sunflower oil, 75% extra virgin olive oil + 25% rice oil and 87.5% high oleic sunflower oil + 12.5% coconut oil) were used in the production of taralli as an extra virgin olive oil alternative. The lipid fraction, texture and sensory characteristics, and oxidative evaluation of the final products were studied. The use of the oil blend made of 75% extra virgin olive oil and 25% rice oil gave the best compromise for the content of sterols and tocols resulting in a combination that was able to achieve an induction period, in the accelerated oxidation test, that was comparable to that of the reference control made with extra virgin olive oil only.

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.

Chemical Profile of Cold-Pressed Beech Nut (Fagus sylvatica L.) Oil

The objective of this study was to assess the chemical characteristics of cold-pressed beech nut oil. The nuts, gathered from the forest, comprised 25.35% water, 13.19% oil, and 19.40% protein. The predominant fatty acid was linoleic acid (40.5%), followed by oleic acid (35.0%) and gondoic acid (7.7%). All four tocopherols were present in the oil, with γ-tocopherol being the dominant form at 99.38 mg per 100 g of oil. The total sterol content was 2708.73 mg per kg of oil, with β-sitosterol constituting 80.5% of all sterols. The main characteristics of the oil included its relatively high tocopherol and gondoic acid content, a dominant oleic–linoleic fatty acid profile, and elevated levels of carotenoids.

Squalene production under oxygen limitation by Schizochytrium sp. S31 in different cultivation systems

The triterpene squalene is widely used in the food, cosmetics and pharmaceutical industries due to its antioxidant, antistatic and anti-carcinogenic properties. It is usually obtained from the liver of deep sea sharks, which are facing extinction. Alternative production organisms are marine protists from the family Thraustochytriaceae, which produce and store large quantities of various lipids. Squalene accumulation in thraustochytrids is complex, as it is an intermediate in sterol biosynthesis. Its conversion to squalene 2,3-epoxide is the first step in sterol synthesis and is heavily oxygen dependent. Hence, the oxygen supply during cultivation was investigated in our study. In shake flask cultivations, a reduced oxygen supply led to increased squalene and decreased sterol contents and yields. Oxygen-limited conditions were applied to bioreactor scale, where squalene accumulation and growth of Schizochytrium sp. S31 was determined in batch, fed-batch and continuous cultivation. The highest dry matter (32.03 g/L) was obtained during fed-batch cultivation, whereas batch cultivation yielded the highest biomass productivity (0.2 g/L*h−1). Squalene accumulation benefited from keeping the microorganisms in the growth phase. Therefore, the highest squalene content of 39.67 ± 1.34 mg/g was achieved by continuous cultivation (D = 0.025 h−1) and the highest squalene yield of 1131 mg/L during fed-batch cultivation. Volumetric and specific squalene productivity both reached maxima in the continuous cultivation at D = 0.025 h−1 (6.94 ± 0.27 mg/L*h−1 and 1.00 ± 0.03 mg/g*h−1, respectively). Thus, the choice of a suitable cultivation method under oxygen-limiting conditions depends heavily on the process requirements.Key points• Measurements of respiratory activity and backscatter light of thraustochytrids• Oxygen limitation increased squalene accumulation in Schizochytrium sp. S31• Comparison of different cultivation methods under oxygen-limiting conditions

Changes in the Characteristics of Pine Logging Residue during Storage in Forest Stands

A significant amount of logging residue is produced during roundwood harvesting. Logs are often left in forest sites due to, for example, ecological or logistical aspects. Taking into account the fact that the number of studies focused on changes in the properties of the residue is very low, it was decided to conduct research on the effect of a three-year storage period in forest stands on the chemical properties and energy potential of the wood. The research design allowed for the determination of changes during up to three years of storage. The performed analysis showed a highly negative impact on the characteristics of the material. These adverse effects were probably caused by the activity of microorganisms such as fungi and bacteria, as evidenced by the increased concentrations of ergosterol and low-molecular-weight organic acids. Moreover, it was found that wood stored for three years was characterized by a lower cellulose content; an increased percentage of lignin; a reduced content of sterols (desmosterol, stigmasterol, lanosterol and β-sitosterol) and phenolic acids; and reduced antioxidant activity, as determined with the ABTS+ method. Storing logs also led to a reduction in the energy potential of the residues, as shown by a reduction in net and gross calorific value and an increased ash content.

Comparison of structural effects of cholesterol, lanosterol, and oxysterol on phospholipid (POPC) bilayers

Membrane sterols contribute to the function of biomembranes by regulating the physical properties of the lipid bilayers. Cholesterol, a typical mammalian sterol, is biosynthesized by oxidation of lanosterol. From a molecular evolutionary perspective, lanosterol is considered the ancestral molecule of cholesterol. Here, we studied whether cholesterol is superior to lanosterol in regulating the physical properties of the lipid bilayer in terms of the structural effect on model biomembranes composed of a phospholipid. For comparison, oxysterol, which is formed by oxidation of cholesterol, was also studied. The phospholipid used was 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), which is abundantly found in mammalian biomembranes, and 7β-hydroxycholesterol, which is highly cytotoxic, was used as the oxysterol. The apparent molecular volume was calculated from the mass density determined by the flotation method using H2O and D2O, and the bilayer thickness was determined by reconstructing the electron density distribution from X-ray diffraction data of the POPC/sterol mixtures at a sterol concentration of 30 mol%. The apparent occupied area at the bilayer surface was calculated from the above two structural data. The cholesterol system had the thickest bilayer thickness and the smallest occupied area of the three sterols studied here. This indicates that the POPC/cholesterol bilayer has a better barrier property than the other two systems. Compared to cholesterol, the effects of lanosterol and 7β-hydroxycholesterol on lipid bilayer properties can be interpreted as suboptimal for the function of mammalian biomembranes.

Flavor enhancement of strong fragrant rapeseed oils by enzymatic treatment

Fragrant rapeseed oils with the sensory characteristics attract increasing market in China. The unique flavor of strong fragrant rapeseed oil (SFRO) is the first choice to attract the consumers’ preference. Thus, enzymatic treatments of rapeseeds were used to enhance the flavor properties of SFROs in the present study. Results showed that SFRO produced from neutral protease and α-amylase-treated rapeseeds (NRO+ARO) had the highest percentages of unsaturated fatty acid (USFA), monounsaturated fatty acid (MUSFA) and oleic acid (C18:1) of 93.30%, 65.90% and 65.22%, respectively, with the highest tocopherol content of 577.35 mg/kg and total sterol content of 4523.46 mg/kg. The NRO+ARO showed a strong nutty and rich roasted fragrance and distinguishing sweet flavor with the highest overall sensory evaluation score. Majority of volatile compounds in NRO+ARO belonged to pyrazines and furans originated from Maillard reactions with the highest contents. The highest decrease trends of monosaccharide and amino acid contents from 8.42 g/kg to 2.04 g/kg and from 128.91 mg/kg to 47.39 mg/kg, respectively, were observed in the neutral protease and α-amylase-treated rapeseeds after roasting. Glucose/xylose-lysine reaction products contained the high contents of pyrazines, suggesting enhancement of supply of glucose/xylose and lysine in rapeseeds would significantly improve the fragrance of SFROs. The outputs of present study would provide a clue to understand the formation of unique flavor of SFROs and a reference to develop series of SFRO products.

Assessment of applying an integrated pest management strategy to control the raspberry leaf and bud mite, Phyllocoptes gracilis (Nal.) and its effect on the raspberry leaf metabolites

In the years 2018‒2020, the effectiveness of three synthetic active substances (acequinocyl, fenpyroximate, spirodiclofen), one substance derived from Streptomyces spp. (abamectin), a plant extract (orange oil) and silicone polymers in controlling Phyllocoptes gracilis in two Polish raspberry plantations (v. ‘Glen Ample’) was assessed. All the substances showed high and comparable efficacy against the tested pest, significantly reducing its population. However, their effects occurred at different times after the application. The strongest immediate control was shown by silicone polymers, followed by abamectin and spirodiclofen. The full effect of fenpyroximate application was visible after approx. 2 weeks, while acequinocyl was effective 3‒4 weeks after the application. Moreover, the content of phenolic compounds, sterols and triterpenoids was determined in leaves of plants treated with spirodiclofen, orange oil and silicone polymers. The observed increase in the content of salicylic acid and changes in the content of triterpenoids in leaves may indicate a stimulating effect of the substances to the natural defense processes of plants.

Lipid composition and physicochemical parameters of unrefined sunflower oil

Unrefined sunflower oil is obtained by pressing of the sunflower seeds and subsequent fine filtration. It contains more biologically active substances compared to the refined one, it is more stable to oxidation processes, for that reason it is widely used in the composition of the various food products. The main acids in the oil are oleic (56.5%), linoleic (31.7%), palmitic (6.4%), and stearic acid (3.2%). Total sterol content is 0.7%, with ß-sitosterol as a main component (84.0%). The quantity of tocopherol is 188 mg/kg and it consists of one compound α-tocopherol (100%). Different physicochemical parameters were obtained at temperature ranges (from 20 to 80°C). The values of these parameters decrease with an increase in temperature, density (from 0.938 to 0.901 g/ml), surface tension (from 44.124 to 31.787 mN/m), dynamic viscosity (from 29.195 to 14.913 mPa.s), and kinematic viscosity (from 31.125 to 16.552 mm2/s). All these changes are in confirmation of the data from the literature and are relevant in our next studies.