Search Results (137)

Nutrition plays a fundamental role in promoting health and preventing chronic diseases, with bioactive food components offering a therapeutic potential in biomedical applications. Among these, edible oils are recognised for their functional properties, which contribute to disease prevention and metabolic regulation. The proposed study aims to evaluate the quality of four bioactive oils (olive oil, sunflower oil, tomato seed oil, and pumpkin seed oil) by analysing their thermal behaviour through infrared (IR) imaging. The study designed a customised electronic system to acquire thermographic signals under controlled temperature and humidity conditions. The acquisition system was used to extract thermal data. Analysis of the acquired thermal signals revealed characteristic heat absorption profiles used to infer differences in oil properties related to stability and degradation potential. A hybrid deep learning model that integrates Convolutional Neural Networks (CNNs) with Long Short-Term Memory (LSTM) units was used to classify and differentiate the oils based on stability, thermal reactivity, and potential health benefits. A signal analysis showed that the AI-based method improves both the accuracy (achieving an F1-score of 93.66%) and the repeatability of quality assessments, providing a non-invasive and intelligent framework for the validation and traceability of nutritional compounds. Full article

Natural polymer-based nanoparticles have emerged as promising stabilizers for Pickering emulsions, offering biocompatibility, environmental sustainability, and improved protection of active compounds. This study developed chitosan/gum arabic (CH/GA) nanoparticles as solid stabilizers for quercetin-loaded Pickering emulsions to enhance the stability and antioxidant bioactivity of quercetin (QE), a plant-derived flavonoid known for its potent radical-scavenging activity but limited by oxidative degradation. A systematic formulation strategy was employed to evaluate the effects of CH/GA concentration (0.5–2.0% w/v), oil type (olive, soybean, sunflower, and coconut), and oil volume fraction (ϕ = 0.5–0.7) on emulsion stability. The formulation containing 1.5% CH/GA and olive oil at ϕ = 0.6 exhibited optimal physical and interfacial stability. Quercetin (0.1% w/w) was incorporated into the optimized emulsions and characterized for long-term stability, particle size, droplet morphology, rheology, antioxidant activity (DPPH), cytocompatibility, and intracellular reactive oxygen species (ROS) protection using HaCaT keratinocytes. The olive oil-based formulation (D1-QE) exhibited greater viscosity retention and antioxidant stability than its soybean-based counterpart (E2-QE) under both room temperature (RT) and accelerated heating–cooling (H/C) storage conditions. Confocal microscopy confirmed the accumulation of CH/GA nanoparticles at the oil–water interface, forming a dense interfacial barrier and enhancing emulsion stability. HPLC analysis showed that D1-QE retained 92.8 ± 0.5% of QE at RT and 82.8 ± 1.5% under H/C conditions after 30 days. Antioxidant activity was largely preserved, with only 4.7 ± 1.7% and 14.9 ± 4.8% loss of DPPH radical scavenging activity at RT and H/C, respectively. Cytotoxicity testing in HaCaT keratinocytes confirmed that the emulsions were non-toxic at 1 mg/mL QE and effectively reduced H₂O₂-induced oxidative stress, decreasing intracellular ROS levels by 75.16%. These results highlight the potential of CH/GA-stabilized Pickering emulsions as a polymer-based delivery system for maintaining the stability and functional antioxidant activity of QE in bioactive formulations. Full article

This study presents a novel approach combining near-infrared (NIR) spectroscopy with multivariate calibration to develop simplified yet robust regression models for evaluating the quality of various edible oils. Using a reduced number of NIR wavelengths selected via the stepwise decorrelation method (SELECT) and ordinary least squares (OLS) regression, the models quantify pigments (carotenoids and chlorophyll), antioxidant activity, and key sensory attributes (rancid, fruity green, fruity ripe, bitter, and pungent) in nine extra virgin olive oil (EVOO) varieties. The dataset also includes low-quality olive oils (e.g., refined and pomace oils, supplemented or not with hydroxytyrosol) and sunflower oils, both before and after deep-frying. SELECT improves model performance by identifying key wavelengths—up to 30 out of 700—and achieves high correlation coefficients (R = 0.86–0.96) with low standard errors. The number of latent variables ranges from 26 to 30, demonstrating adaptability to different oil properties. The best models yield low leave-one-out (LOO) prediction errors, confirming their accuracy (e.g., 1.36 mg/kg for carotenoids and 0.88 for rancidity). These results demonstrate that SELECT–OLS regression combined with NIR spectroscopy provides a fast, cost-effective, and reliable method for assessing oil quality under diverse processing conditions, including deep-frying, making it highly suitable for quality control in the edible oils industry. Full article

This study investigates the impact of hydroxytyrosol (HTyr) supplementation on the fatty acid profiles and oxidative stability of various extra virgin olive oil (EVOO) cultivars and other edible oils during prolonged deep-frying. EVOO cultivars including Picual, Cornicabra, Empeltre, Arbequina, Hojiblanca, Manzanilla, Royuela, Koroneiki, and Arbosana were analyzed alongside two sunflower oils and three refined olive oils under thermal stress at 170–210 °C for 3–6 h. HTyr consistently preserved monounsaturated fatty acids (MUFAs), particularly oleic acid (C18:1), while significantly reducing the degradation of polyunsaturated (PUFAs) and saturated fatty acids (SFAs) (p < 0.05) in many oil samples; for example, in olive oil °1, TMUFAs in Exp 1 revealed 7.28%, while in Exp 5 (with HTyr), TMUFAs increased to 7.47%. In olive oil °0.4, TMUFAs increased from 8.52% in Exp 1 to 9.17% in Exp 5. Additionally, In EVOO cv. Picual, total SFAs increased slightly, from 16.58% in Exp 1 to 16.96%, in Exp 5. Notably, total MUFA content (TMUFAs) was best preserved in Manzanilla (81.92%), followed by Hojiblanca (78.52%), Empeltre (78.09%), olive oil 1° (78.20%), Koroneiki (77.60%), and Arbosana (77.01%) (p < 0.05), indicating strong oxidative resistance. In Arbequina and Royuela oils, oleic acid retention also exceeded 76% after deep-frying. HTyr helped maintain fatty acid profiles within EU regulatory limits across most cultivars, despite minor exceedances in specific SFAs, such as lignoceric acid (C24:0), likely due to varietal traits or harvest timing. Principal component analysis (PCA) revealed distinct clustering patterns: sunflower oils grouped around linoleic acid (C18:2), reflecting high PUFA content, while olive oils clustered near oleic and palmitic acids. Cultivars such as Picual, Empeltre, Manzanilla, and Royuela showed unique associations with lignoceric acid, supporting the use of fatty acid profiles as cultivar-specific markers. HTyr supplementation enhanced oxidative stability and quality retention across oil types in terms of fatty acids profile, corroborating previous findings on the resilience of polyphenol-rich EVOOs under thermal stress. Furthermore, fatty acid composition varied significantly according to cultivar, HTyr, and deep-frying (p < 0.05), highlighting the complexity of oil quality determinants. This study supports the application of HTyr as a natural antioxidant to improve thermal stability and nutritional quality, not only in olive oils but also in other edible oils. These findings promote sustainable practices aligned with circular economy principles and advance the understanding of fatty acid dynamics during deep-frying. HTyr-enriched oils present promising potential in both culinary and industrial contexts. Full article

Obesity represents a chronic metabolic disorder feature by dysregulated glucose-lipid homeostasis. We investigated the effects of flaxseed oil (FO), rich in α-linolenic acid, and its blended oil (BO) on high-fat diet-induced obese mice. In the BO, the mass ratio of flaxseed oil, sunflower oil (as a source of linoleic acid), and olive oil (as a source of oleic acid) was precisely set at 11.90:51.64:36.46 (w/w/w) After 13 weeks of supplementation, both FO and BO significantly suppressed weight gain (multiple comparisons of weight gain on week 13: 8.57 ± 1.25 g in the ND group; 25.08 ± 2.96 g in the HFD group; 19.35 ± 1.47 g/19.71 ± 2.96 g in the HFD+FO/HFD+BO group), fat accumulation, and restored dyslipidemia (notably, FO administration resulted in a significant reduction in LDL-C and LEP levels (p < 0.01)), elevated blood glucose (FO demonstrated a more pronounced effect compared to BO), and liver tissue damage (specifically, FO exhibited a more pronounced effect in decreasing the levels of oxidative stress markers, including alanine aminotransferase (ALT) and malondialdehyde (MDA), and BO demonstrated greater efficacy in ameliorating the histopathological conditions of liver tissue) in HFD-fed mice. The 16S rRNA gene sequencing of mice fecal samples showed that FO and BO reduced the Firmicutes/Bacteroidetes (F/B) ratio (supplementation with FO decreased the F/B ratio from 68.95 to 15.24 (p < 0.01), while BO supplementation reduced it from 68.95 to 19.47), decreased the abundance of Proteobacteria (supplementation with FO decreased the abundance of Proteobacteria from 0.21 to 0.15, whereas supplementation with BO reduced it to 0.17). In addition, FO increased the abundance of Clostridium, and BO increased the abundance of Lactobacillus (rose from 5.42 to 10.3), reversing the imbalance of gut microbiota in obese mice. These findings suggest that FO and BO may be promising dietary strategies for treating obesity and improving its associated metabolic disorders. Full article

Chitosan is recognized by its capacity to bind lipids based on the viscosity and degree of deacetylation. We analyzed the in vitro binding of Procambarus clarkii chitosan (PCC) with extra virgin olive oil and sunflower oil at temperatures and pH levels that approximate gastric-like conditions. In the tube test, 4 mg of PCC and 0.3 g of either EVO or of SO oils were mixed by stirring in test tubes with 4 mL of water acidified with HCl to a pH of 3. The PCC binding capability was determined by measuring the differences between the suspension without PCC and the suspension with PCC added. A scanning electron microscope (SEM) was utilized to further observe the uniformity and morphology of the emulsified PCC/oil hydrogels. In the test tube, PCC was shown to have a 1:11 (w/w) binding capacity for EVO and 1:15 (w/w) for SO. The SEM-based examination demonstrated a smooth surface with fine porosity of the microstructure of either PCC/oil hydrogel, proving successful emulsification. Under conditions similar to those in the stomach after a meal, including acidity, mixed composition, and temperature, PCC efficiently binds and emulsifies EVO and SO. Full article

The covering oils of twenty-two commercially canned sardines were studied by Proton Nuclear Magnetic Resonance spectroscopy (¹H NMR) freshly purchased and also after storage at room temperature for fifteen years. The filling oils studied were olive oils (one extra-virgin olive oil), sunflower oils, soybean oils, and vegetable oils (unspecified origin). The aim was to obtain qualitative and quantitative information on lipid composition, oxidative and hydrolytic status, and on the changes occurring during storage. Just after purchase, in all the samples, the migration of fish omega-3 polyunsaturated eicosapentaenoic (EPA, C20:5ω3) and docosahexaenoic (DHA, C22:6ω3) acyl groups was reported; the occurrence of oxidative or hydrolytic reactions was not observed. After storage, the main change in the spectra was the presence of signals due to hydrolytic compounds (mainly 1,3-diglycerides, together with 1,2-diglycerides, 1-monoglycerides, and lower proportions of 2-monoglycerides). In eleven samples very low concentrations of saturated aldehydes (alkanals) were detected, which is considered a low oxidative status. It is suggested that the above-mentioned partial glycerides and alkanals migrated from sardine muscle to the oils. The content in omega-3 lipids in the oils after storage indicated the occurrence of lipid interchange between the sardine muscle and the packing oil in both directions. Full article

This study investigates the performance of biobased and nano-additive lubricants for the sustainable machining of Al6082 alloy. The experiments were conducted in five different cutting environments: dry cutting, olive oil-based minimum quantity lubrication (MQL), sunflower oil-based MQL, olive oil-based MQL with nano-SiO₂ additives, and sunflower oil-based MQL with nano-SiO₂ additives. The machining performance was evaluated in terms of key parameters such as surface roughness, cutting forces, tool wear, cutting temperature, and chip morphology. The results show that nano-additive lubricants reduce friction, reduce tool wear, and reduce cutting forces, thus providing lower surface roughness. The nano-SiO₂-additive olive oil-based MQL method showed the optimum performance by providing the lowest cutting force and temperature values. It was also determined that nano-additive lubricants contributed to more regular chip formation. The study reveals that the use of biobased nano-lubricants in sustainable machining processes offers environmental and economic advantages. In the future, it is recommended to examine different types and concentrations of nanoparticles, conduct long-term tool wear analyses, and evaluate the effects on other machining methods. Full article

The current research aims to monitor the physicochemical changes in various varieties of extra virgin olive oils (EVOOs) supplemented with exogenous polyphenolic extract from olive fruit, enriched with hydroxytyrosol (HTyr) and its derivatives, compared to numerous refined olive oils, sunflower oil, and high oleic sunflower oil under different deep-frying conditions (170–210 °C for 3 to 6 h, with/without added HTyr. Acidity, K₂₃₂, K₂₇₀, ∆K, peroxide value (PV), anisidine value (AnV), TOTOX, refractive index (RI), carotenoids, chlorophyll, and antioxidant capacity using DPPH (2,2-diphenyl-1-picrylhydrazyl) approach were evaluated. The results show that EVOO varieties generally exhibit lower acidity and thermal degradation compared to refined olive oils, particularly when deep-fried at 170 °C for 3 h with exogenous HTyr (the best treatment). Royuela, Koroneiki, Empeltre, Manzanilla, and Arbosana EVOO varieties demonstrated lower K₂₃₂ values (1.36, 1.67, 1.79, 1.82, and 1.81, respectively). Under optimal deep-frying conditions, all EVOO varieties fell within the standard K₂₃₂ limit for EVOO (≤2.5), except for Cornicabra. Regarding K₂₇₀, only Royuela (0.11) and Manzanilla (0.22) were below the standard limit of ≤0.22. These two varieties also exhibited the lowest ΔK values (0.00). The findings further revealed that Royuela, Koroneiki, and Manzanilla had the lowest TOTOX values, with 20.76, 23.38, and 23.85, respectively. Moreover, Koroneiki and Arbosana had the highest carotenoid ratios, with values of 17.5 mg/kg and 13.7 mg/kg, respectively. Koroneiki, Arbosana, and olive oil 1° also displayed the highest chlorophyll concentrations, with values of 50.2, 53.7, and 47.5 mg/kg, respectively. Furthermore, the findings from the best deep-frying treatment indicated that all olive oil categories exhibited high scavenging radical activity toward DPPH, even in refined olive oil categories and low-quality original olive oil due to the addition of HTyr. In conclusion, deep-fried EVOOs enriched with HTyr at 170 °C/3 h are thermally stable, exhibiting low hydrolysis, low oxidation, higher antioxidant potential, and stable chlorophyll and carotenoid levels. The addition of HTyr to deep-frying oils not only enhances the health benefits of EVOO, supporting EFSA health claims but also acts as a promising stabilizer for the olive oil industry, particularly under high-temperature processing conditions over prolonged periods. This highlights its potential for industrial use as a natural alternative to synthetic antioxidants, not only for olive oil but also for other edible oils, with practical applications in the food industry to improve the quality and stability of frying oils. Full article

Edible oils are essential dietary components that provide crucial micronutrients. However, their quality can deteriorate during frying—a common cooking method—and with prolonged light exposure due to chemical reactions such as hydrolysis, oxidation, and polymerization. These processes lead to the formation of harmful compounds, particularly aldehydes. This study investigates how thermal and light exposure impact the chemical composition of five widely used edible oils: olive, rapeseed, sunflower, sesame, and peanut oils. For the thermal treatment, the oils were heated to 190 ± 5 °C in a commercial fryer, with samples taken at the start and after 10 min and 60 min of heating, while intermittently frying chicken nuggets to simulate typical frying conditions. For the light exposure treatment, the oil samples were exposed to direct sunlight for 3 and 8 h, with control samples being collected beforehand. The oil composition was analyzed using an advanced 800 MHz nuclear magnetic resonance (NMR) instrument with a triple-resonance inverse cryoprobe, providing high sensitivity and resolution. The results revealed a significant increase in various aldehyde compounds in all oils under both thermal and light exposure conditions. Notably, this study identified the generation of genotoxic and cytotoxic α,β-unsaturated aldehydes, including 4-hydroperoxy-(E)-2-alkenals, 4-hydroxy-(E)-2-alkenals, and 4,5-epoxy-(E)-2-alkenals. Given the established association of aldehydes with health risks, including cancer, Alzheimer’s, and Parkinson’s diseases, these findings highlight the importance of monitoring oil degradation during cooking and the appropriate storage of oils to minimize light exposure to reduce potential health risks. Full article

The fast detection of Extra Virgin Olive Oil (EVOO) adulteration with poorer quality and lower price vegetable oils is important for the protection of consumers and the market of olive oil from fraudulent activities, the latter exhibiting an increasing trend worldwide during the last few years. In this work, two optical spectroscopic techniques, namely, Laser-Induced Breakdown Spectroscopy (LIBS) and UV-Vis-NIR absorption spectroscopy, are employed and are assessed for EVOO adulteration detection, using the same set of olive oil samples. In total, 184 samples were studied, including 40 EVOOs and 144 binary mixtures with pomace, soybean, corn, and sunflower oils, at various concentrations (ranging from 10 to 90% w/w). The emission data from LIBS, related to the elemental composition of the samples, and the UV-Vis-NIR absorption spectra, related to the organic ingredients content, are analyzed, both separately and combined (i.e., fused), by Linear Discriminant Analysis (LDA), Support Vector Machines (SVMs), and Logistic Regression (LR). In all cases, very highly predictive accuracies were achieved, attaining, in some cases, 100%. The present results demonstrate the potential of both techniques for efficient and accurate olive oil authentication issues, with the LIBS technique being better suited as it can operate much faster. Full article

This review provides an overview of the main vegetable oils of different botanical origin and composition that can be used for frying worldwide (olive and extra-virgin olive oil, high-oleic sunflower oil, rapeseed oil, peanut oil, rice bran oil, sunflower oil, corn oil, soybean oil, cottonseed oil, palm oil, palm kernel oil and coconut oil) and their degradation during this process. It is well known that during this culinary technique, oil’s major and minor components degrade throughout different reactions, mainly thermoxidation, polymerization and, to a lesser extent, hydrolysis. If severe high temperatures are employed, isomerization to trans fatty acyl chains and cyclization are also possible. The factors conditioning frying medium degradation are addressed, including oil composition (unsaturation degree, fatty acyl chain length and “free” fatty acid content, and presence of beneficial and detrimental minor components), together with frying conditions and food characteristics. Likewise, this review also tackles how the frying oil and other processing conditions may impact on fried food quality (oil absorption, texture, flavor and color). Finally, potential health implications of fried food consumption are briefly reviewed. Full article

In this article, we present a unique system for identifying edible oils through the analysis of their thermophysical properties. The method is based on the use of active infrared thermography. The heating of the oils results from the optical absorption of laser radiation at a specified wavelength. This approach enables greater selectivity in differentiating between various types of edible oils, as the results depend not only on the thermal properties of the specific oils but also on their optical properties, which are uniquely characteristic of each oil. Additionally, the developed system provides a detailed visualization of spatial temperature gradients within the sample’s volume, as well as their changes over time. It overcomes the limitations of other methods that determine only the thermal conductivity coefficients of oils through resistive heating of the sample. In this article, four types of vegetable oils (extra virgin olive oil, sesame oil, sunflower oil, and rapeseed oil) have been studied. Fatty acid analysis, differential scanning calorimetry, and UV-VIS spectroscopy have been used to determine the authenticity, moisture content, and optical properties of the studied samples. The developed system allows for the visualization and determination of the emerging temperature gradients in the sample volume. Full article

This study presents a fast, non-invasive method to determine the iodine value (IV) of edible oils using Time Domain Nuclear Magnetic Resonance (TD-NMR) and Magnetic Resonance Imaging (MRI) techniques. The IV, which quantifies the degree of unsaturation in fats and oils, is a key parameter in assessing oil quality and detecting potential adulteration. Different edible oils were used in this study (sunflower, soy, olive, sesame, and linseed). Statistically significant regression models (R² > 0.92) were established between the IV derived from NMR spectra and the longitudinal (T1) and transverse (T2) relaxation times of the oils, which were obtained from MRI and TD-NMR analyses. The regression models obtained allow for the prediction of the IV from the T1 and T2 relaxation times across a range that includes predominantly mono- and polyunsaturated edible vegetable oils. The TD-NMR approach stands out for its speed (<2 min), lack of sample preparation (including direct analysis within the commercial packaging), and reproducibility, with a variability of only 0.62%. Meanwhile, the MRI technique allows for the simultaneous evaluation of multiple samples in a single acquisition. Together, these features make TD-NMR and MRI effective tools for the rapid and reliable analysis of the IV in edible oils. Full article

Extra virgin olive oil (EVOO) is one of the main daily food items consumed around the world, particularly in the Mediterranean region, and it has unique organoleptic properties. This study aims to determine the best frying conditions of EVOO supplemented with natural exogenous antioxidants enriched in hydroxytyrosol (HTyr) and its derivatives from olive fruit extract (OFE) to conserve its positive sensorial attributes while minimizing its sensorial defects, in particular, rancidity under high thermal processes. In this study, an experienced panel assessed the sensory attributes of nine EVOO varieties, olive oil 0.4° (mixed virgin olive oil (VOO) with refined olive oil (ROO)), Orujo olive oil, and olive oil 1° (EVOO mixed with ROO), compared with two sunflower oil types, performed using a deep-frying (D-F) process with numerous variables, i.e., frying time, frying temperature, and the addition of polyphenols enriched with HTyr. Results showed that most EVOO samples were stable under D-F at 170 °C for 3 h, with added polyphenols (∼650 mg/kg). Moreover, at these best values, the results stated that Arbequina, Picual, Royuella, Hojiblanca, Arbosana, and Manzanilla oils have low rancidity scores with values of 0, 1.7, 1.8, 2.3, 3.1, and 3.7, respectively, and stable/higher positive sensorial attributes, i.e., fruity, bitter, and pungent properties; however, olive oil 1° and olive oil 0.4° have high rancidity and low positive sensorial attributes. Notably, OFE helps maintain bitterness close to control in Picual, Koroneiki, Empeltre, and Arbosana oils. Furthermore, amongst the 19 tested sensory descriptors, only 8 descriptors—namely, fusty/muddy sediment, winey/vinegary/acid/sour, frostbitten olives (wet wood), rancid, fruity (green), fruity (ripe), bitter, and pungent—were successfully developed to allow characterization of the sensory quality of various olive oil categories under D-F. The present research confirmed that OFE may be used to provide stable EVOOs with higher positive sensorial qualities and lower defects and could be used as a natural antioxidant and promising strategy during the D-F process with EVOOs, not only for domestic practices but also at the industrial level. Full article