Gamma tocopherol, its dimmers, and quinones: Past and future trends.

Gamma-tocopherol (γ-T), the major form of vitamin E in many plant seeds and products derived from them, has been attracting increasing attention because of its health-promoting roles. However, the underlying molecular mechanisms are still unclear, to some degree. Furthermore, its dimmers and quinones are expected to be potential nutritious and pharmaceutical agents, however, the knowledge about these dimmers (γ-TBD and γ-TED) and quinones (para- and ortho-quinones) is relatively limited. Thus, a comprehensive summary of the history, chemical structure, source, determination, absorption, transport, and metabolism of its dimmers and quinones compared to γ-T has been reviewed. In addition, the antioxidant activity (AOA) and non-AOA activity of these substances are highlighted. It is suggested that more special attention be paid to the dimmers and quinones for better understanding and further applications.

Physicochemical properties and health risk assessment of polycyclic aromatic hydrocarbons of fragrant rapeseed oils in China.

BACKGROUND: Fragrant rapeseed oil is a type of hot-pressed oil in China. In this study, physicochemical properties, oxidative stability index (OSI), tocopherols, sterols, and polycyclic aromatic hydrocarbons (PAHs) in fragrant rapeseed oils were evaluated. Additionally, the cancer risk assessment pertaining to PAHs in fragrant rapeseed oil was investigated. RESULTS: Acid values (0.64-2.68 mg potassium hydroxide per gram), peroxide values (1.58-4.86 mmol kg-1 ), and color values (R = 2.6-5.8, Y = 35) of fragrant rapeseed oils were all within codex limits. Tocopherols and sterols ranged from 559.5 to 783.7 mg kg-1 and 4412.6 to 7859.8 mg kg-1 respectively. The OSI (110 °C) was between 4.8 and 15.9 h, with an average value of 10.8 h. Mean values of benzo[a]pyrene and PAH4 (chrysene, benz[a]anthracene, benzo[b]fluroranthene, and benzo[a]pyrene) were 2.32 µg kg-1 and 8.21 µg kg-1 respectively. The 95% dietary exposure of benzo[a]pyrene equivalent (BaPeq) contents from PAH4 were 0.3474 ng kg-1 day-1 , 0.3942 ng kg-1 day-1 , 1.8293 ng kg-1 day-1 , and 0.4294 ng kg-1 day-1 for male children, adolescents, adults, and seniors respectively. For females, these values were 0.3443 ng kg-1 day-1 , 0.3228 ng kg-1 day-1 , 1.8697 ng kg-1 day-1 , and 0.4084 ng kg-1 day-1 , respectively. Moreover, incremental lifetime cancer risk values at the cumulative probabilities of 91.3% and 91.6% for male adults and female adults respectively were higher than 1 × 10-5 . CONCLUSION: The results imply that the potential risk of cancer with PAHs in fragrant rapeseed oil should be a concern, especially for the health of adults. Fragrant rapeseed oil is still a product subject to contamination by PAHs. Limits for PAH4 of fragrant rapeseed oil should be included in Chinese regulations to improve safety. © 2020 Society of Chemical Industry.

One-step solvent extraction followed by liquid chromatography-atmospheric pressure photoionization tandem mass spectrometry for the determination of polycyclic aromatic hydrocarbons in edible oils.

A method for rapid analysis of 16 polycyclic aromatic hydrocarbons (PAHs) in edible oils has been developed on the basis of a simplified solvent extraction and liquid chromatography-atmospheric pressure photoionization tandem mass spectrometry performed in multiple reaction monitoring mode. The briefness of the experimental procedure, the use of milliliters of acetonitrile for extraction without any further cleanup process, the short analysis time, and the excellent sensitivity and selectivity demonstrated the advantages of this practical and environmentally friendly method. All the analytes exhibited satisfactory recoveries at three spiking levels (the recoveries ranged from 77.8 to 106.4%), and the relative standard deviations were lower than 10%. The limits of quantitation of this method for the 16 PAHs were in the range of 0.02-0.43 µg/kg. The validated method was successfully applied for the determination of PAHs in coconut oil reference material (BCR-458) and real edible oil samples. The results suggested that a large-scale investigation of the concentration of PAHs in vegetable oils in China is required.

Novel method to analysis benzo[a]pyrene in filter by liquid chromatography/tandem mass spectrometry: application to assess mouth level benzo[a]pyrene exposure.

RATIONALE: Benzo[a]pyrene (B[a]P) is a well-known carcinogenic compound produced from incomplete combustion of organic compounds. During cigarette smoking, cigarette filters trap a portion of mainstream smoke B[a]P and accurate measurement of B[a]P levels in cigarette filter can be used to estimate human exposure level of this compound. METHODS: A rapid and sensitive method to quantify B[a]P levels trapped by cigarette filter was developed. The method is based on liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (LC/APPI-MS/MS). Validation was provided in smoked cigarette filter. RESULTS: The method involved no extensive manual cleanup and concentration steps, hence is easy to use. The limit of detection was 0.064 ng/mL. The recovery ranged from 82.68% to 103.27% and the relative standard deviation (RSD) was less than 7%. A regression model between mainstream cigarette smoke and trapped B[a]P by cigarette filter was established (y = 2.5089x - 0.1851, R(2) = 0.999, n = 6). This model was applied to estimate mouth-level B[a]P exposure of smokers. CONCLUSIONS: The LC/APPI-MS/MS method developed in this work had an excellent throughput in estimating the mouth-level exposure under natural human smoking conditions. Mouth-level B[a]P exposure based on a study of three cigarettes (8, 10 and 13 mg tar levels) showed significant positive correlations with B[a]P trapped by cigarette filter measured (y = 2.5456x - 0.5056, R(2) = 1, n = 249).

Comparative effects of sesame lignans (sesamin, sesamolin, and sesamol) on oxidative stress and lipid metabolism in steatosis HepG2 cells.

Non-alcoholic fatty liver disease (NAFLD) can be attributed to the imbalance between lipogenesis and lipidolysis in the liver. Sesame lignans (sesamin, sesamolin, and sesamol) are unique bioactive compounds responsible for the nutritional function of sesame oils. However, the preventive effects of three lignans on oxidative stress and lipid metabolism in steatosis HepG2 cells have not been compared. In this study, we investigated the role of sesamin, sesamolin, and sesamol on hepatic lipid accumulation and explored the underlying mechanism via a well-established cell model. The results showed that 3 µg/ml of lignans could decrease the TG/TC contents and alleviate cellular oxidative stress, with an order of the lipid-lowering effect as sesamol > sesamin > sesamolin. The lignan-activated AMPK and PPAR signaling pathways enhanced gene and protein expressions related to fatty acid oxidation, cholesterol efflux, and catabolism. Meanwhile, treatment of the steatosis HepG2 cells with sesamin, sesamolin, and sesamol reduced lipid synthesis and cholesterol uptake, thus lowering intracellular lipogenesis in the process of NAFLD. Our data suggested that sesame lignans can attenuate oxidative stress and regulate lipid metabolism in liver cells, which may be potential therapeutic agents for treating the NAFLD. PRACTICAL APPLICATIONS: The present work demonstrated that sesame lignans can be used for dietary supplements or functional additives with excellent lipid-lowering effects. Furthermore, this study supplied potential molecular mechanisms involved in NAFLD treatment process, and also provided nutritional guidelines for sesame oil evaluation and selection.

Sesamol ameliorates hepatic lipid accumulation and oxidative stress in steatosis HepG2 cells via the PPAR signaling pathway.

Non-alcoholic fatty liver disease (NAFLD) is a chronic hepatopathy caused by disordered lipid metabolism in the liver. Sesamol, a phenolic compound derived from sesame oil, has been shown to inhibit obesity, hyperlipidemia, and atherosclerosis in previous investigations. However, the preventive effect of sesamol against hepatic steatosis and oxidative stress in NAFLD has not been well-studied. In this work, sesamol was observed to alleviate lipid accumulation and oxidative stress in high oleic acid (300 µM)/cholesterol (25 µM) induced HepG2 cells, thus indicating that sesamol was involved in regulating hepatic lipid metabolism and oxidative injury. Mechanism studies found that the activated peroxisome proliferator-activated receptors (PPAR) signaling pathway by sesamol intervention up-regulated gene and protein expressions related to fatty acid oxidation and cholesterol efflux and catabolism, thus accelerating lipid consumption and reducing intracellular lipid accumulation in the process of NAFLD. These data suggested that sesamol can effectively ameliorate hepatic steatosis and sesamol riched sesamol oil may be a potential agent for finding therapeutic strategies to treat the NAFLD. PRACTICAL APPLICATIONS: Sesamol and sesamol-rich sesame oil have received much attention due to their performance on hepatic lipid regulation. The results of this study indicate that sesamol treatment could ameliorate hepatic steatosis by inhibiting lipid accumulation and oxidative stress, thus demonstrating that sesamol and sesame oil can be used for functional foods and nutraceutical applications in the future. In addition, the present work provides knowledge of the effects of sesamol on NAFLD and involved mechanisms, and further supplies nutritional guidelines for sesame oil consumption.

Physical Stability, Oxidative Stability, and Bioactivity of Nanoemulsion Delivery Systems Incorporating Lipophilic Ingredients: Impact of Oil Saturation Degree.

There is great interest in the application of a lipid-based delivery system (like nanoemulsion) to improve the bioavailability of lipophilic components. Although emulsion characteristics are believed to be influenced by oil types, there is still a lack of systematic research concentrating on the effect of oil saturation degree on the nanoemulsion quality, especially for evaluation of the bioactivity. Here, we aimed to test the effect of oil saturation degree on the physical stability, oxidative stability, and bioactivity of the designed nanoemulision system. Our findings suggest that the oxidative stability and bioactivity of a nanoemulsion incorporating tocopherol and sesamol highly depend on the oil saturation. A nanoemulsion with an oil with a high degree of unsaturation was more susceptible to oxidation, and addition of tocopherol and sesamol could retard the lipid oxidation. Sesamol exhibited better bioactivity during the experiment compared with tocopherol in the Caenorhabditis elegans (C. elegans) model. The lipid-lowering effect of tocopherol and sesamol increased with lower saturation oil groups. The antioxidant activity of tocopherol and sesamol was higher in the high saturation oil groups. Overall, the obtained data is meaningful for applications using the designed systems to deliver lipophilic ingredients.

Chemical composition and antioxidant capacity of extracts from the whole berry, pulp and seed of Hippophae¨ rhamnoides ssp. yunnanensis.

In the present study, profiles of fatty acid, sn-2 fatty acid, triglyceride, phytochemical (including tocopherol/tocotrienol, phytosterol, flavonoid, carotenoid and polyphenol) and antioxidant capacity of extracts from the whole berry, pulp and seed of Hippophae¨ rhamnoides ssp. yunnanensis were investigated and compared. The distributions of fatty acid, sn-2 fatty acid and triglyceride that was identified using ultra-performance liquid chromatography tandem quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) showed obvious differences among the different parts of the ssp. yunnanensis. The whole berry and pulp extracts exhibited high flavonoid, carotenoid and polyphenol contents, whereas, the seed portion expressed high tocopherol/tocotrienol and phytosterol concentrations. Results deduced from this study demonstrated that ssp. yunnanensis is a rich source of unsaturated fatty acid and bioactive minor component, which should be further developed and utilized by breeders and planters.

Quantification of polycyclic aromatic hydrocarbons and phthalic acid esters in deodorizer distillates obtained from soybean, rapeseed, corn and rice bran oils.

In this study, simple GC-MS methods for analysising sixteen PAHs and seven PAEs were individually established. The LOQs for PAHs and PAEs were ranging from 0.18 to 0.42 µg/kg and 0.19 to 1.50 µg/kg, respectively. The recoveries for DD samples were in the range of 84.8-115.5% and 84.2-109.3% for PAHs and PAEs, respectively. Furthermore, PAHs and PAEs concentrations in soybean, rapeseed, corn and rice bran oil distillates were evaluated. PAHs were found in all the DD samples and the concentrations of BaP, PAH4 and total PAHs were 0.89-55.58, 8.11-326.07 and 115.77-966.40 µg/kg, respectively. Correspondingly, total PAEs concentrations ranged from 2.45 to 24.52 mg/kg, and the mean value was 7.76 mg/kg. The results illustrated that the contents of PAHs and PAEs in the DDs were extremely higher than those in the edible oils, thus indicating that specific issues should be considered in the vegetable oil DDs and DD-based products.

Effect of sea-buckthorn pulp and flaxseed residues on quality and shelf life of bread.

The use of natural products as food supplements has received increasing attention in recent years. Sea-buckthorn pulp and flaxseed residues are rich in phenolic fractions and aroma substances, thereby offering high antioxidant and antimicrobial activity. However, large quantities of these residues usually remain unused. Therefore, this study confirmed the chemical composition and antioxidant and antimicrobial capacity of these materials, and evaluated their effect on the quality, characteristics and shelf life of bread. Both residues were rich in crude fiber, while sea-buckthorn had a much higher content of polyphenols compared with flaxseed. The addition of these two residues changed the characteristics and nutritional value of the bread, including the specific volume, color, texture, and antioxidant capacity. Supplementation with these two residues also gave the breads new aromas. The shelf life of the breads was increased by different levels of addition compared with the control group. For sensory evaluation, bread with a suitable content of residues was favored by consumers.

The relationship between lipid phytochemicals, obesity and its related chronic diseases.

The prevalence of obesity has received global attention in recent years, and lipid consumption has been considered as one of the direct reasons for obesity and related diseases. However, increasing evidence has indicated that edible vegetable oils could exert non-negligible physiological benefits in the daily diet, including suppression of appetite, lowering of blood lipids, prevention of adipocyte synthesis, and reduction of inflammatory response. Bioactive phytochemicals in lipids and oils, such as tocopherol, phenolic compounds, and phytosterol, play an important role in these effects according to in vitro and in vivo studies. For these reasons, the present review focusses on minor bioactive components in oil and their anti-obesity effects, aiming to provide a systematic overview of the relationships between these minor components and obesity and related diseases.

Survey of polycyclic aromatic hydrocarbons of vegetable oils and oilseeds by GC-MS in China.

There is a lack of information regarding the occurrence and content of contamination of polycyclic aromatic hydrocarbon (PAH) in edible vegetable oils and oilseeds used for oil production in China. By combining the advantages of ultrasound-assisted extraction, low temperature separation and silica SPE purification, a method for the determination of the USEPA, 16 PAHs was developed based on GC-MS to fill this gap. The method recoveries for oils and oilseeds were 84.4-113.8% and 84.3-115.3%, respectively. The LODs and LOQs for 16 PAHs were ranged from 0.06-0.17 and 0.19-0.56 µg kg(-1), respectively. Based on the established method, PAH concentrations in 21 edible oils and 17 oilseeds were determined. Almost all the PAHs were found in all the samples tested, especially the light PAHs (LPAHs). Three oil samples exceeded the maximum level of 10 µg kg(-1) for BaP set by China. However, five and six oil samples, respectively, exceeded the maximum limits of 2 and 10 µg kg(-1) set for BaP and PAH4 by the European Union. The concentrations of PAH16 in oilseed samples were 1.5 times higher than corresponding oil samples. The relationships between PAH4 and PAH8, PAH4 and PAH16 as well as PAH8 and PAH16 indicates that PAH4 is a sufficient surrogate for the contamination level of PAHs in edible oils when compared with PAH8.

Widespread occurrence of phthalic acid esters in raw oilseeds in China used for edible vegetable oil production.

Seven different phthalic acid esters (PAEs) were quantified in 124 samples of 16 types of oilseeds from China using a simplified GC-MS method. Di-2-ethylhexyl phthalate and di-n-butyl phthalate were found in all tested oilseed samples. Each made a high contribution to the summed total PAEs. Total PAE concentrations in 124 oilseeds ranged from 0.14 to 3.05 mg kg(-1), and the mean was 0.99 mg kg(-1). Mandulapalka (Cyperus esculentus) samples were the most severely contaminated among all the tested specimens; maize germ samples were least contaminated. Di-n-octyl phthalate and butylbenzyl phthalate were not detected in 12 and five types of oilseeds, respectively. Only eight samples contained all seven analytes. No difference was observed between woody oil-bearing plant and herbaceous oil-bearing plant in terms of PAEs content.

Simultaneous determination of five mercapturic acid derived from volatile organic compounds in human urine by LC-MS/MS and its application to relationship study.

Acrylonitrile, acrolein, 1,3-butadiene, benzene, and crotonaldehyde are hazard volatile organic compounds in tobacco smoke, which can be metabolized to mercapturic acids (MAs) excreted in urine. MAs are can be regarded as important and specific biomarkers to evaluate exposure to those carcinogenic volatile organic compounds. A simultaneous determination of N-acetyl-S-2-cyanoethyl-cysteine (CEMA), 3-hydroxypropyl)-L-cysteine (3-HPMA), N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-acetyl-S-(phenyl)-L-cysteine (SPMA) and 3-hydroxy-1-methylpropylmercapturic acid (HMPMA) derived from five volatile organic compounds by column-switching LC-MS/MS has been described. MAs were concentrated and cleaned up by an online reusable pre-column packed with restricted access material. The intra- and inter-day precisions of the method ranged from 0.7% to 15.2%. The LODs was 0.013-0.053 ng/mL. The recovery of the whole analytical procedure ranged from 79.3% to 116%. After validation, this method was successfully applied to urine samples from smokers (n=246) and nonsmokers (n=58). The results showed MAs in urine from smokers were significantly higher than that in nonsmoker except for SPMA. Urinary CEMA significantly correlated with 3-HPMA (r=0.763, P<0.0001) and HMPMA (r=0.910, P<0.0001). CEMA, 3-HPMA and HMPMA are potential biomarkers to distinguish the differences between smokers and nonsmokers.