An innovative carbon dots polarity probe based on intramolecular charge-transfer for visual monitoring of the total polar materials in frying oil.

The presence of Total Polar Materials (TPM) in edible oils is a crucial indicator for assessing oil quality. It is of paramount importance to develop a rapid and dependable technique for monitoring polarity in frying oil. Sensitive polarity responsive fluorescence carbon dots (F-CDs) were synthesized by using p-phenylenediamine as precursors and 2-formylphenylboronic acid pinacol ester (2-FAPE) as a post-modifier. The construction of the fluorescent probe F-CDs involved a strong intramolecular charge-transfer (ICT) mechanism, with 2-FAPE serving as the electron-withdrawing fluorophore and the π-conjugated structure acting as a potent electron-donating group. A strong linear relationship was observed between the emission wavelength and the TPM value of frying oil within a range of 11% to 30%. Notably, the fluorescence color of the probe transitioned from blue to yellow under UV light at 365 nm as the TMP value increased. This study expands the range of sensing applications for CDs in food safety.

Plant-based calcium silicate from rice husk ash: A green adsorbent for free fatty acid recovery from waste frying oil.

Driven by the urgent need for a solution to tackle the surge of rice husk (RH) and waste frying oil (WFO) waste accumulation at a global scale, this report highlights the use of calcium silicates (CS) extracted from acid-pre-treated rice husk ash (RHA) for free fatty acid (FFA) removal from WFO as conventional RHA shows limited FFA adsorption performance. A novel alkaline earth silicate extraction method from acid-pre-treated RHA was outlined. The structural and behavioural attributes of the synthesised CS were identified through BET, SEM-EDS, and XRD analyses and compared to those of RHA. Notable morphology and structural modification were determined, including reducing specific surface areas, mitigating from amorphous to crystalline structure with regular geometric forms, and detecting Si-O-Ca functional groups exclusive to CS adsorbents. A comparison study showed superior lauric acid (LA) adsorption performance by CS absorbents over acid-pre-treated RHA, with a significant increase from 0.0831 ± 0.0004 mmol LA/g to 2.5808 ± 0.0011 mmol LA/g after 60 min. Recognised as the best-performing CS adsorbent, CS-1.0 was used for further investigations on the effect of dosage, LA concentration, and temperature for efficient LA adsorption, with up to 100% LA removal and 5.6712 ± 0.0016 mmol LA/g adsorption capacity. The adsorption isotherm and kinetic studies showed LA adsorption onto CS-1.0 followed Freundlich isotherm with KF = 0.0598 mmol(1-1/n) L(1/n) g-1 & Qe,cal = 3.1696 mmol g-1 and intraparticle diffusion model with kid = 0.1250 mmol g-1 min0.5 & Ci = 0.9625 mmol g-1, indicating rapid initial adsorption and involvement of carboxylate end of LA and the calcium ions on the CS-1.0 in the rate-limiting step. The high equilibrium adsorption capacity and LA adsorption rate indicated that the proposed CS-1.0 adsorbent has excellent potential to recover FFA from WFO effectively.

Rapid quantitative evaluation of total polar materials (TPM) in frying oil based on an "off-on" fluorescence viscosity response probe.

The content of total polar material (TPM) is considered as a comprehensive indicator to evaluate the quality of edible oils which should be discarded and no longer be used when TPM content exceeding 27 %. Nevertheless, there is currently a lack of a convenient and efficient TPM detection method, which is a meaningful challenge. With the increase of TPM content, the viscosity of frying oil grows, and the two maintain a satisfactory positive correlation. Consequently, an "off-on" fluorescence probe TCF-PR method based on viscosity-response has been developed. There exists a good linear relationship between the fluorescence intensity of the probe and the TPM content of soybean oil ((R2 = 0.9936) and salad oil (R2 = 0.9878), accompanying with the advantage of fast response (3 s), which means the rapid detection of TPM can be realized to determine the quality of frying oil in the field of food safety.

Study by means of 1H nuclear magnetic resonance of the oxidation process in high oleic sunflower oil and palm oil during deep-frying of fish cakes.

This study aimed to compare the frying performance of palm oil (PO) and high oleic sunflower oil (HOSO) during frying aquatic products. The quality change and frying performance of HOSO and PO during frying of fish cakes were investigated. The oxidation and hydrolysis products of both oils were explored by the nuclear magnetic resonance technique. The results showed that the color deepening rate of PO was higher than that of HOSO. After 18 h of frying, the total polar compound content of PO and HOSO reached 25.67% and 27.50%, respectively. HOSO had lower degree of oxidation than PO after 24 h of continuous frying. The polyunsaturated fatty acid content in HOSO and PO significantly decreased. The oleic acid content in HOSO remained above 80% during the frying process. The major aldehydes in both oils were (E, E)-2,4-alkadienals and n-alkanals and glycerol diesters (DAGs) were abundant in PO. Furthermore, the addition of fish cakes had slight effect on the quality of the frying oil. Therefore, HOSO is an appropriate candidate for frying owing to its excellent frying stability and nutritional value.

Evaluation of ELISA Test Kits for Detection of Milk Protein in Frying Oil Treated at Different Temperatures.

Milk is a common ingredient in fried foods. Allergen cross-contact can occur through the reuse of frying oil. To enable assessment of the allergy risk of reused oil, methods for quantification of milk protein in oil are needed. This study evaluated four commercial ELISA test kits in comparison with the 660 nm total protein assay for the detection of milk protein in oil after frying. Corn oil spiked with nonfat or whole milk powder were fried at 150 °C or 180 °C for 3 min and were analyzed by ELISA kits either directly or after preextraction with phosphate-buffered saline containing 0.05% Tween (PBST). All four ELISA kits performed well in quantifying milk protein in unheated oil, achieving normalized recoveries of 72.1-115.9% compared with that determined in reference solutions (PBST spiked with nonfat or whole milk powder, 100%). Frying lowered the amount of protein detected, but the extent of reduction differed between test kits. In nonfat milk powder-spiked oil fried at 150 °C, normalized recoveries determined by Veratox Total Milk and BioKits BLG Assay (49.9% and 43.6%, respectively) were higher than that determined by the 660 nm assay (25.4%). Normalized recoveries determined by ELISA Systems Casein and Beta-Lactoglobulin (BLG) kits were substantially lower (9.7% and 2.4%, respectively). In samples fried under typical frying temperature (180 °C), very little protein (0.1-7.4%) was detected. Inclusion of PBST preextraction improved the detection of the two test kits targeting BLG but lowered the level of protein detected by Veratox and ELISA Systems Casein in fried samples. Overall, the ELISA kits evaluated could effectively quantify milk protein in unheated oil without the need to remove the oil phase prior to analysis. Heat treatment was the key factor negatively affecting protein quantitation. Such impact needs to be considered when ELISA test results are used for assessing the allergy risk of reused frying oil.

The bioprotective role of irradiated hibiscus against harmful effects of using repeatedly frying edible oil

Abstract Repeatedly frying process of dietary edible oil has a potential role in the generation of free radicals. Therefore, questions have always been raised as to whether, there is an efficient and economical method to reduce the harmful effects of repeated use of frying edible oil. Since hibiscus has been stated to have a wide variety of therapeutic effects, it was important to investigate its properties against harmful effects of free radicals. The current study aspires to find out whether irradiated powder of hibiscus has a protective role against adverse effects of repeated use of frying edible oil. Thirty-five adult male albino rats were equally assigned into five groups. First groupG1 was fed with normal diet as control group, meanwhile, groupG2 the diet mixed with fresh oil, G3 diet mixed with repeatedly frying oil only, G4 diet mixed with frying oil treated with hibiscus and G5 diet mixed with frying oil treated with irradiated hibiscus. Feeding duration was six weeks. Fatty acid analyses of oil as well as peroxide values were determined. Blood and liver samples were collected for biochemical analyses as well as histological study. Repeatedly heated cooked oil has significant increases in peroxide value, acid value, free fatty acid and both conjugated diene and triene compared with repeatedly frying oil treated with hibiscus. Also there are significant increases in cholesterol and triglyceride and impaired in liver functions in G3compared with others. In addition, relative to the hibiscus groups, there is a substantial reduction in oxygen consumption in G3. Both hibiscus as well as irradiated hibiscus attract attention in order to play a vital and economical role against harmful effects of frequent use of frying edible oil on some biological functions but, irradiated hibiscus was more effective.

Resumo O processo de fritura repetida de óleo comestível da dieta tem papel potencial na geração de radicais livres que podem ter efeitos prejudiciais em algumas funções biológicas. Portanto, sempre se questionou se existe uma maneira eficiente e econômica de prevenir ou pelo menos reduzir os efeitos nocivos do uso repetido de óleo comestível para fritar. Como o hibisco tem ampla variedade de efeitos terapêuticos, foi importante investigar suas propriedades como agente antioxidante contra os efeitos nocivos dos radicais livres. O presente estudo pretende descobrir se o pó irradiado de hibisco tem papel protetor contra os efeitos adversos do uso repetido de óleo comestível para fritar. Trinta e cinco ratos albinos machos adultos foram divididos igualmente em cinco grupos. O primeiro grupo G1 foi alimentado com dieta normal como grupo controle, enquanto o grupo G2 dieta misturada com óleo fresco, dieta G3 misturada com óleo de fritura repetida, dieta G4 misturada com óleo de fritura tratada com hibisco e dieta G5 misturada com óleo de fritura tratada com hibisco irradiado. A duração da alimentação foi de seis semanas. Foram determinadas as análises de ácidos graxos de óleo, bem como os valores de peróxidos. Amostras de sangue e fígado foram coletadas para análises bioquímicas e estudo histológico. O óleo cozido repetidamente aquecido tem aumentos significativos no valor de peróxido, valor de ácido, ácido graxo livre e dieno e trieno conjugados em comparação com óleo de fritura repetidamente tratado com hibisco. Também há aumentos significativos no colesterol e triglicérides e comprometimento das funções hepáticas no G3 em comparação com outros. Além disso, em relação aos grupos de hibiscos, há uma redução substancial no consumo de oxigênio no G3. Tanto o hibisco como o hibisco irradiado chamam atenção por desempenhar papel vital e econômico contra os efeitos nocivos do uso frequente de óleo comestível para fritar em algumas funções biológicas, mas o hibisco irradiado foi mais eficaz.

The bioprotective role of irradiated hibiscus against harmful effects of using repeatedly frying edible oil / O papel bioprotetor do hibisco irradiado contra os efeitos nocivos do uso de óleo comestível para fritar

Abstract Repeatedly frying process of dietary edible oil has a potential role in the generation of free radicals. Therefore, questions have always been raised as to whether, there is an efficient and economical method to reduce the harmful effects of repeated use of frying edible oil. Since hibiscus has been stated to have a wide variety of therapeutic effects, it was important to investigate its properties against harmful effects of free radicals. The current study aspires to find out whether irradiated powder of hibiscus has a protective role against adverse effects of repeated use of frying edible oil. Thirty-five adult male albino rats were equally assigned into five groups. First group"G1" was fed with normal diet as control group, meanwhile, group"G2" the diet mixed with fresh oil, "G3" diet mixed with repeatedly frying oil only, "G4" diet mixed with frying oil treated with hibiscus and "G5" diet mixed with frying oil treated with irradiated hibiscus. Feeding duration was six weeks. Fatty acid analyses of oil as well as peroxide values were determined. Blood and liver samples were collected for biochemical analyses as well as histological study. Repeatedly heated cooked oil has significant increases in peroxide value, acid value, free fatty acid and both conjugated diene and triene compared with repeatedly frying oil treated with hibiscus. Also there are significant increases in cholesterol and triglyceride and impaired in liver functions in "G3"compared with others. In addition, relative to the hibiscus groups, there is a substantial reduction in oxygen consumption in "G3". Both hibiscus as well as irradiated hibiscus attract attention in order to play a vital and economical role against harmful effects of frequent use of frying edible oil on some biological functions but, irradiated hibiscus was more effective.

Resumo O processo de fritura repetida de óleo comestível da dieta tem papel potencial na geração de radicais livres que podem ter efeitos prejudiciais em algumas funções biológicas. Portanto, sempre se questionou se existe uma maneira eficiente e econômica de prevenir ou pelo menos reduzir os efeitos nocivos do uso repetido de óleo comestível para fritar. Como o hibisco tem ampla variedade de efeitos terapêuticos, foi importante investigar suas propriedades como agente antioxidante contra os efeitos nocivos dos radicais livres. O presente estudo pretende descobrir se o pó irradiado de hibisco tem papel protetor contra os efeitos adversos do uso repetido de óleo comestível para fritar. Trinta e cinco ratos albinos machos adultos foram divididos igualmente em cinco grupos. O primeiro grupo "G1" foi alimentado com dieta normal como grupo controle, enquanto o grupo "G2" dieta misturada com óleo fresco, dieta "G3" misturada com óleo de fritura repetida, dieta "G4" misturada com óleo de fritura tratada com hibisco e dieta "G5" misturada com óleo de fritura tratada com hibisco irradiado. A duração da alimentação foi de seis semanas. Foram determinadas as análises de ácidos graxos de óleo, bem como os valores de peróxidos. Amostras de sangue e fígado foram coletadas para análises bioquímicas e estudo histológico. O óleo cozido repetidamente aquecido tem aumentos significativos no valor de peróxido, valor de ácido, ácido graxo livre e dieno e trieno conjugados em comparação com óleo de fritura repetidamente tratado com hibisco. Também há aumentos significativos no colesterol e triglicérides e comprometimento das funções hepáticas no "G3" em comparação com outros. Além disso, em relação aos grupos de hibiscos, há uma redução substancial no consumo de oxigênio no "G3". Tanto o hibisco como o hibisco irradiado chamam atenção por desempenhar papel vital e econômico contra os efeitos nocivos do uso frequente de óleo comestível para fritar em algumas funções biológicas, mas o hibisco irradiado foi mais eficaz.

Revealing oxidative degradation of lipids and screening potential markers of four vegetable oils during thermal processing by pseudotargeted oxidative lipidomics.

The oxidative degradation of lipids in vegetable oils during thermal processing may present a risk to human health. However, not much is known about the evolution of lipids and their non-volatile derivatives in vegetable oils under different thermal processing conditions. In the present study, a pseudotargeted oxidative lipidomics approach was developed and the evolution of lipids and their non-volatile derivatives in palm oil, rapeseed oil, soybean oil, and flaxseed oil under different thermal processing conditions was investigated. The results showed that thermal processing resulted in the oxidative degradation of TGs in vegetable oils, which generated oxTGs, DGs, and FFAs, as well as TGs with smaller molecular weights. The lower the fatty acid saturation, the more severe the oxidative degradation of vegetable oils and thermal processing at high temperatures should be avoided if possible. From the accumulation of oxTGs concentrations, the hazards during thermal processing at high temperatures were, in descending order, soybean oil, rapeseed oil, flaxseed oil, and palm oil. The non-volatile potential markers were screened in palm oil, rapeseed oil, soybean oil, and flaxseed oil for 1, 7, 5, and 2 markers related to thermal processing time, respectively. The study provided suggestions for the consumption of vegetable oils from multiple perspectives and identified markers for monitored oxidative degradation of vegetable oils.

Effects of Different Frying Oils Composed of Various Fatty Acids on the Formation of Multiple Hazards in Fried Pork Balls.

Oil oxidation products can react with food substrates to produce harmful substances, and oil saturation is closely related to oil oxidation in the process of frying. Therefore, the influence of the composition of fatty acids in oil on the formation of harmful substances in fried pork balls was explored. The five frying oils with the lowest unsaturated fatty acid (UFA) content, ranked in ascending order, were palm oil, peanut oil, soybean oil, corn oil, and colza oil (64.94%, 79.94%, 82.65%, 83.07%, and 92.26%, respectively). The overall levels of four harmful substances (acrylamide, polycyclic aromatic hydrocarbons, heterocyclic amines, and trans fatty acids) found in the oil used to fry pork balls followed a descending order: canola oil, corn oil, peanut oil, soybean oil, and palm oil (33.66 µg/kg, 27.17 µg/kg, 23.45 µg/kg, 18.67 µg/kg, and 13.19 µg/kg, respectively). This order was generally consistent with the trend in the content of UFAs. Therefore, the formation of harmful substances is closely related to the saturation of oil. Compared with other frying oils, soybean oil as a household oil produces relatively low amounts of harmful substances and has less negative impact on the quality (oil content, moisture content, and higher protein digestibility) of fried products.

Aerobic exercise training reduces deep-frying oil-induced apoptosis of hippocampal tissue by reducing oxidative stress in male rats.

Deep-frying oil (DFO) contains high amounts of free radicals, and consuming foods prepared with this method causes damage to nervous tissue due to oxidative stress (OS). Since moderate-intensity aerobic exercise training (AT) reduces OS, the current search investigated the effects of AT on OS, apoptosis, and neurogenesis markers in the hippocampal tissue of DFO-fed rats. Eighteen Wistar male rats (200-280 gr) were randomly allocated to a control group fed with normal food (Con-ND), a control group receiving DFO (Con-DFO), and a group receiving DFO-aerobic exercise (EX-DFO) (n = 6 in each). DFO was gavaged for four weeks, five days a week, with a dose of 2 ml. AT included running on a treadmill for four weeks and five sessions per week (40 min per session). The expression of genes B-cell lymphoma 2 (BCL-2), Protein X associated with Bcl-2 (BAX), Caspase-3 (Casp-3), and Caspase-9 (Casp-9) was measured by PCR method. The ELISA method was used to calculate levels of Superoxide dismutase (SOD) and Catalase (CAT) activity, malondialdehyde (MDA), and Brain-Derived Neurotrophic Factor (BDNF). Also, the expression of the proteins Cannabinoid receptor type 1(CB1), Cannabinoid receptor type2 (CB2), Glial fibrillary acidic protein (GFAP), Neuronal nuclei (NeuN), and DNA fragmentation was evaluated by Immunohistochemical and TUNEL staining. DFO feeding led to a significant increase in apoptotic markers, such as BAX, Casp-3, and Casp-9 gene expression, and DNA fragmentation (p ≤ 0.05) while decreasing BDNF concentration SOD activity (p ≤ 0.05). AT significantly reduced the BAX, Casp-3, Casp-9, MDA, CB1, GFAP, and DNA fragmentation (p ≤ 0.05). In conclusion, AT can reduce the harmful effects of feeding with DFO on the hippocampal tissue.

Antioxidant activity of selected plants extract for palm oil stability via accelerated and deep frying study.

Antioxidants are organic compounds that help to prevent lipid oxidation and improve the shelf-life of edible oils and fats. Currently, synthetic antioxidants were used as oil stabilizing agent. However, synthetic antioxidants have been causing various health risks. As a result, natural antioxidants such as most parts of olive plant, green tea, sesame, medicinal plants were plays an important role to retard lipid oxidation. The palm oil was continuously frying at 180 °C for 6 days using Lepidium sativum (0.2%w/v) and Aframomum corrorima (0.3%w/v) seeds extracts as antioxidant. The physicochemical properties of oil in the herbal extract additive group significantly maintained the oil quality during frying compared to the normal control and the food sample containing group. The L. sativum extract had a greater oil stability compared to A. corrorima extract. However, the frying oil without herbal extract significantly increase the physicochemical properties of oil such as iodine value, acid value, free fatty acid, total polar compounds, density, moisture content, pH etc. during repetitive frying. The antioxidant activity of the plant extract was outstanding, with an IC50 value in the range of 75-149.9 µg/mL when compared to the standard butyl hydroxy anisole, which had an IC50 value in the range of 74.9 ± 0.06-96.7 ± 0.75 µg/mL. The total phenolic and flavonoid content of the extract for L. sativum was 128.6 ± 0.00 mg GAE/g, 127.0 ± 0.00 mg QE/g, and 130.16 ± 0.001 mg GAE/g, 105.76 ± 0.02 mg QE/g, respectively. The significant effect of the plant extract on the degradation of oil and the formation of free fatty acids was confirmed by Fourier transform infrared spectroscopy. The result of these study revealed that the ethanolic crude extract of L. sativum and A. corrorima had a potential natural antioxidant to prevent the degradation of palm oil.

The Effect of Oil-Rich Food Waste Substrates, Used as an Alternative Carbon Source, on the Cultivation of Microalgae-A Pilot Study.

Microalgae are mostly phototrophic microorganisms present worldwide, showcasing great adaptability to their environment. They are known for producing essential metabolites such as carotenoids, chlorophylls, sterols, lipids, and many more. This study discusses the possibility of the mixotrophic abilities of microalgae in the presence of food waste oils. The utilization of food waste materials is becoming more popular as a research subject as its production grows every year, increasing the environmental burden. In this work, waste frying oil and coffee oil were tested for the first time as a nutrition source for microalgae cultivation. Waste frying oil is produced in large amounts all over the world and its simple purification is one of its greatest advantages as it only needs to be filtered from leftover food pieces. Coffee oil is extracted from waste spent coffee grounds as a by-product. The waste frying oil and coffee oil were added to the basic algal media as an alternative source of carbon. As a pilot study for further experimentation, the effect of oil in the medium, algal adaptability, and capability to survive were tested within these experiments. The growth and production characteristics of four algae and cyanobacteria strains were tested, of which the strain Desmodesmus armatus achieved exceptional results of chlorophyll (8.171 ± 0.475 mg/g) and ubiquinone (5.708 ± 0.138 mg/g) production. The strain Chlamydomonas reindhartii showed exceptional lipid accumulation in the range of 30-46% in most of the samples.

Conversion of Mixed Waste Food Substrates by Carotenogenic Yeasts of Rhodotorula sp. Genus.

The consequence of the massive increase in population in recent years is the enormous production of mainly industrial waste. The effort to minimize these waste products is, therefore, no longer sufficient. Biotechnologists, therefore, started looking for ways to not only reuse these waste products, but also to valorise them. This work focuses on the biotechnological use and processing of waste oils/fats and waste glycerol by carotenogenic yeasts of the genus Rhodotorula and Sporidiobolus. The results of this work show that the selected yeast strains are able to process waste glycerol as well as some oils and fats in a circular economy model and, moreover, are resistant to potential antimicrobial compounds present in the medium. The best-growing strains, Rhodotorula toruloides CCY 062-002-004 and Rhodotorula kratochvilovae CCY 020-002-026, were selected for fed-batch cultivation in a laboratory bioreactor in a medium containing a mixture of coffee oil and waste glycerol. The results show that both strains were able to produce more than 18 g of biomass per litre of media with a high content of carotenoids (10.757 ± 1.007 mg/g of CDW in R. kratochvilovae and 10.514 ± 1.520 mg/g of CDW in R. toruloides, respectively). The overall results prove that combining different waste substrates is a promising option for producing yeast biomass enriched with carotenoids, lipids, and beta-glucans.

Production and optimization of novel Sphorolipids from Candida parapsilosis grown on potato peel and frying oil wastes and their adverse effect on Mucorales fungal strains.

BRIEF INTRODUCTION: Mucormycosis disease, which has recently expanded with the Covid 19 pandemic in many countries, endangers patients' lives, and treatment with common drugs is fraught with unfavorable side effects. AIM AND OBJECTIVES: This study deals with the economic production of sophorolipids (SLs) from different eight fungal isolates strains utilizing potato peels waste (PPW) and frying oil waste (FOW). Then investigate their effect against mucormycetes fungi. RESULTS: The screening of the isolates for SLs production revealed the highest yield (39 g/100 g substrate) with most efficiency was related to a yeast that have been identified genetically as Candida parapsilosis. Moreover, the characterizations studies of the produced SLs by FTIR, 1H NMR and LC-MS/MS proved the existence of both acidic and lactonic forms, while their surface activity was confirmed by the surface tension (ST) assessment. The SLs production was optimized utilizing Box-Behnken design resulting in the amelioration of yield by 30% (55.3 g/100 g substrate) and ST by 20.8% (38mN/m) with constant level of the critical micelle concentration (CMC) at 125 mg/L. The studies also revealed the high affinity toward soybean oil (E24 = 50%), in addition to maintaining the emulsions stability against broad range of pH (4-10) and temperature (10-100℃). Furthermore, the antifungal activity against Mucor racemosus, Rhizopus microsporus, and Syncephalastrum racemosum proved a high inhibition efficiency of the produced SLs. CONCLUSION: The findings demonstrated the potential application of the SLs produced economically from agricultural waste as an effective and safer alternative for the treatment of infection caused by black fungus.

Levels and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Vegetable Oils and Frying Oils by Using the Margin of Exposure (MOE) and the Incremental Lifetime Cancer Risk (ILCR) Approach in China.

A total of 139 vegetable oils and 48 frying oils produced in China were tested for the levels of 15 Environmental Protection Agency-regulated polycyclic aromatic hydrocarbons (PAHs). The analysis was completed by high-performance liquid chromatography-fluorescence detection (HPLC-FLD). The limit of detection and limit of quantitation were ranged between 0.2-0.3 and 0.6-1 µg/kg, respectively. The average recovery was 58.6-90.6%. The highest mean of total PAHs was found in peanut oil (3.31 µg/kg), while the lowest content was found in olive oil (0.39 µg/kg). In brief, 32.4% of vegetable oils exceeded the European Union maximum levels in China. The detected level of total PAHs in vegetable oils was lower than the frying oils. The mean dietary exposure to PAH15 ranged from 0.197 to 2.051 ng BaPeq/kg bw/day. The margin of exposure values was greater than 10,000, and the cumulative probabilities of the incremental lifetime cancer risk of different age groups were less than the priority risk level (10-4). Therefore, there was no potential health concern for specific populations.

Spectroscopic studies on thermal degradation and quantitative prediction on acid value of edible oil during frying by Raman spectroscopy.

The health risks posed by harmful substances resulting from the thermal degradation of frying oils are of great concern. Characteristic peak intensity ratios (PIRs) screened from Raman spectra were used to characterize the thermal degradation. High correlation coefficients between PIRs and acid values (AVs) of 0.972 (linear fitting), 0.984 (logarithmic function fitting), and 0.954 (linear fitting) for fried soybean oil, canola oil, and palm oil, were obtained at the PIRs of I1267/I1749, I1267/I1659, and I1267/I1749, respectively. The highly correlated PIRs common to the three oils were determined by Pearson's correlation coefficient combined with heat maps. To accommodate both linear and nonlinear features, a global model for predicting AVs of multi-varieties frying oils was constructed using a least-squares support vector machine algorithm, and the results performed well with a root mean square error of prediction of 0.016 and a ratio of prediction to deviation of 11.351. The whole results demonstrate that Raman spectroscopy could characterize the thermal degradation and has excellent quantitative analysis ability for food control based on AV in frying oils, thus providing a new approach to quality control of frying oils.

Oxidative lipidomics to elucidate the non-volatile derivatives of four typical triglycerides in vegetable oils under simulated frying conditions.

Vegetable oils with different saturations have varied composition of triglycerides (TGs) and produce different non-volatile derivatives during oxidation. Precise characterization of the non-volatile derivatives of TGs is essential for understanding the degradation of TGs and the production pattern of non-volatile derivatives. Oxidative lipidomics was combined with collision-induced dissociation and electron-activated dissociation to elucidate the precise structures of non-volatile derivatives produced under simulated frying conditions by 1,3-dipalmitoyl-2-oleoylglycerol (POP), triolein (OOO), trilinolein (LLL), and trilinolenin (LnLnLn). The results indicate that the unsaturated fatty acyl chains at the sn-2 position were more susceptible to oxidation compared with those at the sn-1/3 position. Species of non-volatile derivatives included epoxy-, hydroperoxy-, hydroxy-, and oxo-TGs, as well as degradation products. The potential reaction pathways of TGs and their non-volatile derivatives were also proposed. This study elucidated oxidative degradation mechanisms of the four typical TGs and provided a theoretical basis for changes of vegetable oils during frying.

Dietary oxidized frying oil activates hepatic stellate cells and accelerates the severity of carbon tetrachloride- and thioacetamide-induced liver fibrosis in mice.

Deep-frying is a common cooking practice worldwide, and after repeated heating's, the oil undergoes various chemical reactions, including hydrolysis, polymerization, lipid oxidation, and the Maillard reaction. Studies have pointed out that oxidized dietary frying oil may cause teratogenesis in mice and increase cancer and cardiovascular risks. The liver is the main organ involved in dietary nutrient catabolism, detoxification, bile production, and lipid metabolism. Nevertheless, the effects of oxidized frying oil exposure on the activation of hepatic stellate cells (HSCs) and liver fibrosis are still unclear. In this study, we showed that exposure to oxidized frying oil enhanced the sensitivity of HSCs to transforming growth factor (TGF)-ß1-induced α-smooth muscle actin (α-SMA), collagen 1a2, collagen 1a1, metalloproteinase-2, and phosphorylated smad2/3 activation. In both carbon tetrachloride (CCl4)- and thioacetamide (TAA)-induced liver fibrosis mouse models, we showed that long-term administration of a 10% fried oil-containing diet significantly upregulated fibrogenesis genes expression and deposition of hepatic collagen. Furthermore, long-term fried oil exposure not only promoted macrophage infiltration and increased inflammatory-related gene expression, but also accumulated excess cholesterol and lipid peroxidation in the liver tissues. In conclusion, our study demonstrated that feeding a fried oil-containing diet may trigger TGF-ß1-induced HSCs activation and thereby promote liver damage and fibrosis progression through enhancing the inflammatory response and lipid peroxidation.

Validity of total polar compound and its three components in monitoring the evolution of epoxy fatty acids in frying oil: Fast food restaurant conditions.

This study evaluated the validity of total polar compounds (TPC) and its three components in monitoring the evolution of epoxy fatty acids in frying oil under fast food restaurant conditions. The content of epoxy fatty acids can be predicted using the TPC rather than oxidized triglyceride monomer. When TPC content reached 24 g/100 g, 25 g/100 g, and 27 g/100 g, the epoxy fatty acid content in oil was found to be 1.47-3.63 mg/g, 1.58-4.06 mg/g, and 1.83-5.08 mg/g, respectively. More epoxy fatty acids were generated in high oleic sunflower oil than in canola and cottonseed oil during frying. At current discarding points of TPC 24-27 g/100 g, its epoxy fatty acid content was 3.63-5.08 mg/g, which was lower than the limit of 7 mg/g recommended by Max Rubner-Institut in Germany. Our results indicate that the risk of epoxy fatty acids can be monitored using the current TPC index.

Effect of Lactobacillus plantarum on folliculogenesis in deep frying oil-fed rats.

Today, the tendency towards Western World diet characterized by a high consumption of Deep Frying Oil (DFO), as well as female infertility has increased. On the other hand, probiotics are living microorganisms that can benefit human health. Therefore, this study aimed to investigate the effect of a probiotic treatment (Lactobacillus plantarum) on the process of follicular growth in rats fed with DFO. Twenty adult female Wistar rats were divided into four groups: control, DFO treatment, DFO treatment group receiving probiotic and the healthy group receiving probiotic for one month. After blood sampling and dissection, ovarian tissue was examined for the number of ovarian follicles at different stages. In addition, the expression of Bmp15 (Gdf-9b) and Gdf9 genes was assessed by the real-time PCR method. The ELISA test was also used to measure hormonal changes (LH and FSH). Data showed that rats treated with DFO had a significant decrease in follicle numbers, hormone levels and Bmp15 and Gdf9 gene expression. Moreover, the number of atretic follicles was increased. Treatment of rats with the probiotic reduced the observed side effects of DFO. Thus, treatments of rats with the probiotic mitigated some of the observed side effects of DFO. An increase in primordial follicles and a reduction of atretic follicles was indicated compared to the DFO group (P ≤ 0.001). Lactobacillus plantarum could reduce the detrimental effects of DFO on folliculogenesis through its beneficial effects.