Novel high-oleic oil consumption for cardiometabolic health: a narrative review.

Several cardiometabolic disorders are risk factors for cardiovascular diseases (CVDs), and prevention is imperative in reducing the burden of these diseases on the healthcare system. Although novel high-oleic acid oils (HOOs) are now commonly used for high-temperature frying in both foodservice and the manufacture of processed foods, there are still limited data regarding their effects on CVD risk. This narrative review aims to clarify these effects by comparing HOOs with saturated fatty acid (SFA)-rich and polyunsaturated fatty acid (PUFA)-rich oils, first regarding their physicochemical properties and then concerning their effects on CVD risk factors using recent randomized controlled trials (RCTs). Overall, although HOOs are more stable than PUFA-rich oils, they do not have the same high-temperature stability as SFA-rich oils. RCTs demonstrate that HOO consumption improves the plasma lipid profile compared with SFA-rich oils while showing similar effects to those of PUFA-rich oils on CVD risk factors. Finally, the current literature lacks information on the actual consumption of HOOs, their long-term effects on cardiometabolic health, and the impact of prolonged heating of these oils on CVD risk factors. In sum, the short-term intake of HOOs may be beneficial for cardiometabolic health; however, more research is needed.

Large-scale preparation of five polar polyphenols including three isomers from Phyllanthus emblica Linn. by preparative high-speed counter-current chromatography.

The separation of polar compounds is challenging work due to poor retention and insufficient selectivity. In the present study, an efficient strategy for large-scale preparation of five polar polyphenols including three isomers from Phyllanthus emblica Linn has been established by preparative high-speed counter-current chromatography. Macroporous resin column chromatography was used for the enrichment of the polar polyphenols. However, sugar and other ultra-polar impurities were co-washed out with the targets. Liquid-liquid extraction with ethyl acetate/water (1/1, v/v) solvent system was developed to remove the ultra-polar impurities with a clearance rate of 95%. Finally, the targets were introduced to preparative high-speed counter-current chromatography for separation using ethyl acetate/n-butanol/acetic acid/water (2/7/1/10, v/v/v/v) solvent system. As a result, 191 mg of Mucic acid 1,4-lactone 5-O-gallate, 370 mg of ß-Glucogallin, 301 mg of Gallic acid, 195 mg of Mucic acid 1,4-lactone 3-O-gallate and 176 mg of Mucic acid 1,4-lactone 2-O-gallate with purity higher than 98% were obtained from 1.5 g of sample. Mucic acid 1,4-lactone 3-O-gallate, Mucic acid 1,4-lactone 3-O-gallate, and Mucic acid 1,4-lactone 2-O-gallate are isomers. The results showed that high-speed counter-current chromatography could be well developed for the separation of polar compounds from natural products.

Olive Oil Benefits from Sesame Oil Blending While Extra Virgin Olive Oil Resists Oxidation during Deep Frying.

Fresh potatoes were deep-fried in olive oil (OO), extra virgin olive oil (EVOO), and their blends with 5%, 10%, and 20% v/v sesame oil (SO). This is the first report on the use of sesame oil as a natural source of antioxidants during olive oil deep frying. The oil was evaluated for anisidine value (AV), free fatty acids (FFAs), extinction coefficient (K232 and K270), Trolox equivalent antioxidant capacity (TEAC), and total phenols (TPs) until the total polar compounds (TPCs) reached 25%. Sesame lignan transformations were monitored through reversed-phase HPLC. While the TPCs in olive oils increased at a steady rate, the addition of 5%, 10%, and 20% v/v SO delayed TPCs' formation for 1, 2, and 3 h, respectively. The addition of 5%, 10%, and 20% v/v SO increased the olive oil frying time by 1.5 h, 3.5 h, and 2.5 h, respectively. The addition of SO to OO reduced the secondary oxidation products' formation rate. The AV for EVOO was lower than OO and all tested blends, even those with EVOO. EVOO was more resistant to oxidation than OO, as measured by the TPCs and TEAC, while the frying time rose from 21.5 to 25.25 h when EVOO replaced OO. The increase in frying time for OO but not for EVOO, after SO addition, points to a niche market for EVOO in deep frying.

Ion chromatography coupled to Q-Orbitrap for the analysis of formic and oxalic acid in beehive matrices: a field study.

There is an increasing concern about the use of synthetic acaricides to fight the ectoparasitic mite Varroa destructor. Natural products such as formic acid (FA) and oxalic acid (OA) have emerged as a possible alternative control strategy. However, given the difficulty of analysing these highly polar compounds and the lack of robust and reliable methods, there are very few studies of the concentration and distribution of these natural acaricides in the beehive compartments. We present a reliable and simple analytical methodology, based on sample extraction with modified quick polar pesticide (QuPPe) methods followed by ion chromatography coupled to a quadrupole Orbitrap mass analyser for the analysis of FA and OA in honeybees, honey, beeswax, and beebread. The developed methods have been used in a field study for the evaluation of the presence and distribution of FA and OA in the beehive products, as well as in adult bees and bee brood samples, before, during, and up to 3 months after the application of the treatments by the beekeeper. Beebread and honey samples presented the highest concentration levels of OA and FA, respectively, mainly due to their natural presence. As expected, the organic acids showed low persistence in wax after the treatments. The natural acaricides were found in adult and developing bees at concentration levels below the reported LD50 in all the cases; however, residue levels of OA in larvae during the treatment application were very close to the reported LD50.

Large-scale preparation of two minor polar polyphenols from Phyllanthus emblica Linn. by macroporous resin column chromatography and high-temperature preparative high-speed counter-current chromatography.

In the present study, an efficient strategy for the large-scale preparation of two minor polar polyphenols from Phyllanthus emblica L. has been established by macroporous resin column chromatography and high-temperature preparative high-speed counter-current chromatography. Macroporous resin column chromatography was used for the enrichment of the target polyphenols. The target polyphenols could be well enriched in the 10% ethanol fraction and the peak area proportion increased from 2.2% in the crude extract to 85.3% in the 10% ethanol fraction. Then, the 10% ethanol fraction was introduced to preparative high-speed counter-current chromatography for separation using an n-butanol-ethyl acetate-water (17:3:20, v/v/v) solvent system. In order to improve the retention of the stationary phase, a high-temperature preparative high-speed counter-current chromatography had been developed by using a 316 L stainless steel pipe as a column. A 50°C of column temperature was used and the retention rate of the stationary phase could reach 75%. Finally, 871 mg of compound Ⅰ and 534 mg of compound Ⅱ with purities higher than 98% were obtained from 4 g of the sample. The chemical structures were identified as corilagin and 1, 6-di-O-galloyl-ß-D-glucoside by 1 H-NMR and 13 C-NMR.

The Stability of Refined Rapeseed Oil Fortified by Cold-Pressed and Essential Black Cumin Oils under a Heating Treatment.

Polar compounds and polymers are regarded as the most reliable indicators of oil degradation during heating, and it is desirable to find methods to reduce these undesirable changes. The aim of this study was (1) to determine the effect of enrichment with black cumin cold-pressed oil (CP) or essential oil obtained from black cumin cold-pressed oil in an equivalent amount (ES) on limiting the polar compounds and polymers content in blends based on refined rapeseed oil during high-temperature heating in a thin layer; (2) to determine tocochromanol losses and their effect on the change content of the polar compounds and polymers. Four fortified oils were made from refined rapeseed oil and one of the four additives (10% CP, 20% CP, 0.1% ES, and 0.2% ES). All fortified oils and refined rapeseed oil as a control sample were heated at 170 and 200 °C on the pan in a thin layer and evaluated regarding loss of individual tocochromanol homologs by HPLC-FL, polar compounds content, oxidized triacylglycerols (TAG), and polymers content by HPSEC-ELSD. Additionally, the fatty acid profile in nonheated oil was investigated. Tocochromanol analysis showed loss in all the samples. At 170 °C polymers were not detected; no difference was noted for polar compounds and oxidized TAG content; only the 20% CP sample showed a higher level. At 200 °C the 10% CP sample exhibited a significant protective effect with the lowest content of polar compounds, oxidized TAG, and dimers.

Integration of Two-Dimensional Liquid Chromatography-Mass Spectrometry and Molecular Docking to Characterize and Predict Polar Active Compounds in Curcuma kwangsiensis.

Curcuma kwangsiensis, one species of Curcumae zedoaria Ros. c, is a commonly used traditional Chinese medicine (TCM) for treating cardiovascular disease, cancer, asthma and inflammation. Polar compounds are abundant in water decoction, which would be responsible for critical pharmacological effects. However, current research on polar compounds in Curcumae zedoaria Ros. c remains scarce. In this study, the polar fraction from Curcuma kwangsiensis was firstly profiled on G protein-coupled receptor 109A (GPR109A), ß2-adrenergic receptor (ß2-AR), neurotensin receptor (NTSR), muscarinic-3 acetylcholine receptor (M3) and G protein-coupled receptor 35 (GPR35), which were involved in its clinical indications and exhibited excellent ß2-AR and GPR109A receptor activities. Then, an offline two-dimensional reversed-phase liquid chromatography (RPLC) coupled with the hydrophilic interaction chromatography (HILIC) method was developed to separate polar compounds. By the combination of a polar-copolymerized XAqua C18 column and an amide-bonded XAmide column, an orthogonality of 47.6% was achieved. As a result of coupling with the mass spectrometry (MS), a four-dimensional data plot was presented in which 373 mass peaks were detected and 22 polar compounds tentatively identified, including the GPR109A agonist niacin. Finally, molecular docking of these 22 identified compounds to ß2-AR, M3, GPR35 and GPR109A receptors was performed to predict potential active ingredients, and compound 9 was predicted to have a similar interaction to the ß2-AR partial agonist salmeterol. These results were supplementary to the material basis of Curcuma kwangsiensis and facilitated the bioactivity research of polar compounds. The integration of RPLC×HILIC-MS and molecular docking can be a powerful tool for characterizing and predicting polar active components in TCM.

Determination of highly polar compounds in atmospheric aerosol particles at ultra-trace levels using ion chromatography Orbitrap mass spectrometry.

A method using ion chromatography coupled to high-resolution Orbitrap mass spectrometry was developed to quantify highly-polar organic compounds in aqueous filter extracts of atmospheric particles. In total, 43 compounds, including short-chain carboxylic acids, terpene-derived acids, organosulfates, and inorganic anions were separated within 33 min by a KOH gradient. Ionization by electrospray was maximized by adding 100 µL min-1 isopropanol as post-column solvent and optimizing the ion source settings. Detection limits (S/N ≥ 3) were in the range of 0.075-25 µg L-1 and better than previously reported for 22 compounds. Recoveries of extraction typically range from 85 to 117%. The developed method was applied to three ambient samples, including two arctic flight samples, and one sample from Melpitz, a continental backround research site. A total of 32 different compounds were identified for all samples. From the arctic flight samples, organic tracers could be quantified for the first time with concentrations ranging from 0.1 to 17.8 ng m-3 . Due to the minimal sample preparation, the beneficial figures of merit, and the broad range of accessible compounds, including very polar ones, the new method offers advantages over existing ones and enables a detailed analysis of organic marker compounds in atmospheric aerosol particles.

Isolation of three polyoxins by reversed-phase liquid chromatography with pure aqueous mobile phase.

Developing methods for the isolation of highly polar compounds from complex samples is of great significance. In this study, three polyoxins were successfully isolated from a complex sample (PN1-1# ) by preparative high-performance liquid chromatography. Separation was carried out on five polar reversed-phase stationary phases, using pure aqueous as mobile phase, where the C18HC column can provide the best performance for PN1-1# . Next, the effects of the mobile phase composition were studied. It was found that adding NaClO4 can enhance the retention and resolution, and adding NaH2 PO4 was beneficial to maintain good peak shapes when the sample loading increased. Therefore, the optimized mobile phase consisting of 20 mmol NaH2 PO4 and 20 mmol NaClO4 (adding H3 PO4 to adjust pH 2) was used to separate PN1-1# . This method of using 100% aqueous phase can effectively improve both the retention and the solubility of polar samples. Eventually, through further purification, three compounds, namely, polyoxins B, D, and G, were obtained. This paper provided an effective and eco-friendly strategy for the preparative-scale separation of polar samples.

Analytical Platforms for Mass Spectrometry-Based Metabolomics of Polar and Ionizable Metabolites.

Metabolomics studies rely on the availability of suitable analytical platforms to determine a vast collection of chemically diverse metabolites in complex biospecimens. Liquid chromatography-mass spectrometry operated under reversed-phase conditions is the most commonly used platform in metabolomics, which offers extensive coverage for nonpolar and moderately polar compounds. However, complementary techniques are required to obtain adequate separation of polar and ionic metabolites, which are involved in several fundamental metabolic pathways. This chapter focuses on the main mass-spectrometry-based analytical platforms used to determine polar and/or ionizable compounds in metabolomics (GC-MS, HILIC-MS, CE-MS, IPC-MS, and IC-MS). Rather than comprehensively describing recent applications related to GC-MS, HILIC-MS, and CE-MS, which have been covered in a regular basis in the literature, a brief discussion focused on basic principles, main strengths, limitations, as well as future trends is presented in this chapter, and only key applications with the purpose of illustrating important analytical aspects of each platform are highlighted. On the other hand, due to the relative novelty of IPC-MS and IC-MS in the metabolomics field, a thorough compilation of applications for these two techniques is presented here.

Identification of the Olfactory Profile of Rapeseed Oil as a Function of Heating Time and Ratio of Volume and Surface Area of Contact with Oxygen Using an Electronic Nose.

The process of deep fat frying is the most common technological procedure applied to rapeseed oil. During heat treatment, oil loses its nutritional properties and its original consumer quality is lowered, which is often impossible to determine by organoleptic assessment. Therefore, the aim of the study was to correlate markers of the loss of the nutritional properties by rapeseed oil related to the frying time and the surface area of contact with oxygen with changes in the profile of volatile compounds. The investigations involved the process of 6-, 12-, and 18-h heating of oil with a surface-to-volume ratio (s/v ratio) of 0.378 cm-1, 0.189 cm-1, and 0.126 cm-1. Samples were analysed to determine changes in the content of polar compounds, colour, fatty acid composition, iodine value, and total chromanol content. The results were correlated with the emission of volatile compounds determined using gas chromatography and an electronic nose. The results clearly show a positive correlation between the qualitative degradation of the oil induced by prolonged heating and the response of the electronic nose to these changes. The three volumes, the maximum reaction of the metal oxide semiconductor chemoresistors, and the content of polar compounds increased along the extended frying time.

Quality Assessment of Deep-Frying Palm Oil by Impedimetric Sensing with a Simple and Economic Electrochemical Cell.

Quality control of deep-frying oil is a global public health concern. A simple and economic electrochemical chamber composed of two bare screen-printed carbon electrodes (working area: 78.54 × 102 cm2; distance: 0.0055 cm; cell constant: 0.70 × 10-2 cm-1) was constructed for precisely acquiring the impedimetric responses of a high-resistance palm oil sample (RSD < 7%, n = 3). Good correlations between the measured impedance data (charge transfer resistance and logarithmic output impedance (Log Z) obtained in the frequency region <0.1 Hz) and the regulatory quality indicators (total polar compounds and acid value) were achieved (R2 > 0.97), suggesting that the proposed impedimetric sensing method is useful for accurately assessing the deteriorated condition of repeated frying oil. Applications for rapid screening can also be realized because the measurement times of Log Z at any given perturbation frequency from 0.01-1 Hz were all less than 3 min.

Tandem Solid-Phase Extraction Columns for Simultaneous Aroma Extraction and Fractionation of Wuliangye and Other Baijiu.

Wuliangye baijiu is one of the most famous baijiu in China, with a rich, harmonic aroma profile highly appreciated by consumers. Thousands of volatiles have been identified for the unique aroma profile. Among them, fatty acid esters have been identified as the main contributors to the aroma profile. In addition, many non-ester minor compounds, many of which are more polar than the esters, have been identified to contribute to the characteristic aroma unique to Wuliangye baijiu. The analysis of these minor compounds has been challenging due to the dominance of esters in the sample. Thus, it is desirable to fractionate the aroma extract into subgroups based on functional group or polarity to simplify the analysis. This study attempts a new approach to achieve simultaneous volatile extraction and fractionation using tandem LiChrolut EN and silica gel solid-phase extraction (SPE) columns. A baijiu sample (10 mL, diluted in 40 mL of water) was first passed through the LiChrolut EN (1.0 g) column. The loaded LiChrolut EN column was then dried with air and coupled with a silica gel (5.0 g) SPE column with anhydrous Na2SO4 (10.0 g) in between. The volatile compounds were eluted from the LiChrolut EN column and simultaneously fractionated on the silica gel column based on polarity. The simultaneous extraction and fractionation technique enabled the fractionations of all fatty acid esters into less polar fractions. Fatty acids, alcohols, pyrazines, furans, phenols, hydroxy esters, and other polar compounds were collected in more polar fractions. This technique was used to study the volatile compounds in Wuliangye, Moutai, and Fengjiu baijiu. In addition to fatty acid esters, many minor polar compounds, including 2,6-dimethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-3,5-dimethylpyrazine, p-cresol, and 2-acetylpyrrole, were unequivocally identified in the samples. The procedure is fast and straightforward, with low solvent consumption.

Effects of storage on the oxidative stability of acorn oils extracted from three different Quercus species.

BACKGROUND: Acorn fruit and its components and by-products are receiving renewed interest due to their nutritional and phytochemical features. In particular, the oil extracted from acorns is recognized for having high nutritional quality and for being rich in bioactive compounds. Despite the growing interest, few papers are available that consider the evolution of acorn-oil characteristics during storage. Our aim was to investigate the storage-related changes in acorn oils extracted from three Quercus species grown in Algeria (Q. ilex, Q. suber, and Q. coccifera) 180 days after production, with a focus on polar and volatile compounds, not yet investigated. Basic quality parameters, phenolic content, antioxidant activity and induction time were also monitored. RESULTS: The oxidation markers (peroxide value and UV absorptions) increased during storage, whereas antioxidants decreased. A distinctive volatile profile was observed at the time of production, which underwent changes during storage. Polar compounds increased, whereas induction time decreased. The oil extracted from Quercus suber L. was the most affected by storage time. CONCLUSION: Floral and fruity volatile compounds detected in the oils' headspace could explain the pleasant flavor of acorn oils reported by other authors. As with other vegetable oils, storage depletes both volatiles and antioxidants and produces oxidation compounds, such as oxidized triacylglycerols. However, the acorn oils that were studied were quite stable under storage in the dark at room temperature for 6 months. © 2020 Society of Chemical Industry.

Characterization of Polar and Non-Polar Compounds of House Edible Bird's Nest (EBN) from Johor, Malaysia.

This work investigated the polar (PC: protein, amino acid and metabolite) and non-polar (NPC: fatty acid) compounds and bioactivity characteristics of the EBN harvested from the state of Johor in Malaysia. The electrophoretic gels exhibited 15 protein bands (16-173 kD) with unique protein profile. Amino acids analysis by AccQ⋅Tag method revealed 18 types of amino acids in EBN. Metabolite profiling was performed using High-Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometer (HPLC-QTOF/MS) technique and a total of 54 compounds belonging to different groups were detected and identified. These findings help to uncover the relation of therapeutic activity of EBN. The EBN was further extracted with AcOEt and BuOH. The AcOEt extract was fractionated into three fractions (F1 -F3 ), and the high triglyceride content in F2 was verified by gC-FID. The three groups of fatty acids discovered in EBN are 48.43 % of poly-unsaturated (PUFA), 25.35 % of saturated fatty acids (SFA) and 24.74 % of mono-unsaturated fat (MUFA). This is the first time to report results ofEBN, BuOH, and AcOEt extracts and of fraction F2 (TEBN) on their analysis for their antioxidant activities by DPPH, ABTS and catalase assay and for their paraoxonase and anti-tyrosinase activities. The results showed that TEBN exhibited the significant bioactivity in all assays. These findings suggest that TEBN is a good source for natural bioactive compounds in promoting body vigor. Current work widened the content of EBN especially on the triglyceride and also marked the content of specific location (Johor, Malaysia) of EBN origin.

Potential Beneficial Effects of Extra Virgin Olive Oils Characterized by High Content in Minor Polar Compounds in Nephropathic Patients: A Pilot Study.

Extra virgin olive oil (EVOO) is a lipid food, which constitutes a pillar of the Mediterranean diet. A high number of scientific data have demonstrated that it exerts a variety of beneficial effects on human health due to its peculiar chemical composition including fatty acids (98-99%) and other active compounds even if found in a very low percentage (1-2%). Among them, minor polar compounds (MCPs), represented mainly by phenolic compounds, are relevant for their healthy properties, as stated by the European Food Safety Authority's (EFSA) claims. In this paper, we described the results obtained from a pilot in vivo study, focused for the first time on the evaluation of the possible beneficial effects of two EVOOs on chronic kidney disease (CKD) patients after the consumption of 40 mL per day for 9 weeks. The selected EVOOs, traced in the production chain, and characterized by High-Performance Liquid Chromatography (HPLC-DAD-MS) analysis, resulted rich in MCPs and satisfied the EFSA's claim for their content of hydroxytyrosol and derivatives. The results obtained by this in vivo study appear to highlight the potential beneficial role in CKD patients of these EVOOs and are promising for future studies.

Influence of total polar compounds on lipid metabolism, oxidative stress and cytotoxicity in HepG2 cells.

BACKGROUND: Recently, the harmful effects of frying oil on health have been gradually realized. However, as main components of frying oils, biochemical effects of total polar compounds (TPC) on a cellular level were underestimated. METHODS: The effects of total polar compounds (TPC) in the frying oil on the lipid metabolism, oxidative stress and cytotoxicity of HepG2 cells were investigated through a series of biochemical methods, such as oil red staining, real-time polymerase chain reaction (RT-PCR), cell apoptosis and cell arrest. RESULTS: Herein, we found that the survival rate of HepG2 cells treated with TPC decreased in a time and dose dependent manner, and thereby presented significant lipid deposition over the concentration of 0.5 mg/mL. TPC were also found to suppress the expression levels of PPARα, CPT1 and ACOX, elevate the expression level of MTP and cause the disorder of lipid metabolism. TPC ranged from 0 to 2 mg/mL could significantly elevate the amounts of reactive oxygen species (ROS) in HepG2 cells, and simultaneously increase the malondialdehyde (MDA) content from 21.21 ± 2.62 to 65.71 ± 4.20 µmol/mg of protein (p < 0.05) at 24 h. On the contrary, antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) respectively decreased by 0.52-, 0.56- and 0.28-fold, when HepG2 cells were exposed to 2 mg/mL TPC for 24 h. In addition, TPC could at least partially induce the apoptosis of HepG2 cells, and the transition from G0/G1 to G2 phase in HepG2 cells was impeded. CONCLUSIONS: TPC could progressively cause lipid deposition, oxidative stress and cytotoxicity, providing the theoretical support for the detrimental health effects of TPC.

Biodegradability of legacy crude oil contamination in Gulf War damaged groundwater wells in Northern Kuwait.

During the 1991 Gulf War, oil wells in the oil fields of Kuwait were set aflame and destroyed. This resulted in severe crude oil pollution of the countries only fresh water aquifers. Here, for the first time the natural attenuation and biodegradation of the persisting groundwater contamination was investigated to assess potential processes in the aquifer. Biodegradation experiments were conducted under aerobic and multiple anaerobic conditions using microcosms of the contaminated groundwater from Kuwait. Under the conditions tested, a portion of the total petroleum hydrocarbon (TPH) component was degraded, however there was only a slight change in the bulk concentration of the contaminant measured as dissolved organic carbon (DOC), suggesting the presence of a recalcitrant pollutant. Changes in the associated microbial community composition under different reduction-oxidation conditions were observed and known hydrocarbon degraders identified. The results of this study indicate that lingering contaminant still persists in the groundwater and is recalcitrant to further biodegradation, which presents challenges for future remediation plans.

Is frying oil a dietary source of an endocrine disruptor? Anti-estrogenic effects of polar compounds from frying oil in rats.

The objective was to investigate endocrine-disrupting effects of polar compounds from oxidized frying oil. Estrogenicity of polar compounds was tested with a rat uterotrophic bioassay. Dietary oxidized frying oil (containing 51% polar compounds) or polar compounds isolated from it were incorporated into feed (in lieu of fresh soybean oil) and fed to ovariectomized rats, with or without treatment with exogenous ethynyl estradiol. Exogenous estrogen restored uterine weight, and caused histological abnormalities (stratified epithelia and conglomerate glands) as well as proliferation of uterine epithelial cells. However, tamoxifen or polar compounds reduced these effects. Furthermore, tamoxifen or polar compounds down-regulated uterine mRNA expression of estrogen receptor (ER)-target genes, implicating reduced ER activity in this hypo-uterotrophic effect. Inhibition of ER signaling and mitosis by polar compounds were attributed to reduced MAPK and AKT activation, as well as a reduced ligand binding domain-transactivity of ERα/ß. We concluded polar compounds from frying oil are potential endocrine-disrupting chemicals, with implications for food and environmental safety.

Measurement System for Lossy Capacitive Sensors: Application to Edible Oils Quality Assessment.

This paper aimed to develop a portable, low-cost, and easy-to-use measurement system for oil quality degradation assessment. The main two chemical parameters affected by frying are the total polar compounds (TPC) and free fatty acids. The system should characterize the change of chemical parameters by measuring the changes in its dielectric parameters. The dielectric parameters, relative permittivity, and conductivity are measured by measuring the capacitance and resistance of a capacitive sensor dipped in oil. The main challenges are that the corresponding changes of the capacitance and resistance are very small and the presence of stray effects. For this reason, the measurement system should be able to detect changes in capacitance and resistance with high resolution and with good immunity to stray effects. The proposed measurement system is based on the conversion of impedance to voltage and time and combining, therefore, having two measurement methods in one circuit. In this way, it is possible to measure the dielectric and resistive parameters and not only the relative permittivity as was done in previous works. The results showed a strong correlation between the chemical and electrical parameters with a coefficient of determination in the range of 0.9.