Changes in the Antioxidant Properties of Extra Virgin Olive Oil after Cooking Typical Mediterranean Vegetables

The Effect of High-Temperature Heating on Amounts of Bioactive Compounds and Antiradical Properties of Refined Rapeseed Oil Blended with Rapeseed, Coriander and Apricot Cold-Pressed Oils

Cold-pressed oils are rich sources of bioactive substances, which may protect triacylglycerols from degradation during frying. Nevertheless, these substances may decompose under high temperature. This work considers the content of bioactive substances in blends and their changes during high-temperature heating. Blends of refined rapeseed oil with 5% or 25% in one of three cold-pressed oils (rapeseed, coriander and apricot) were heated at 170 or 200 °C in a thin layer on a pan. All non-heated blends and cold-pressed oils were tested for fatty acid profile, content and composition of phytosterols, tocochromanols, chlorophyll and radical scavenging activity (RSA) analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the stability of phytosterols, tocochromanols, DPPH and ABTS values was determined in heated blends. All tocochromanols were lost during the heating process, in particular, at 200 °C. However, there were some differences between homologues. α-Tocopherol and δ-tocopherol were the most thermolabile and the most stable, respectively. Phytosterols were characterized by very high stability at both temperatures. We observed relationships between ABTS and DPPH values and contents of total tocochromanols and α-tocopherol. The obtained results may be useful in designing a new type of fried food with improved health properties and it may be the basis for further research on this topic.

Bioactive compounds in Spanish extra virgin olive oils: Migration and stability according to the culinary technique used

Extra virgin olive oil (EVOO) is a basic food of the Mediterranean diet and an important source of bioactive compounds, especially phenolic substances. The culinary techniques to which the oil is subjected before consumption cause the migration of these compounds, hence the importance of studying their stability before and after culinary treatment. We determined the behaviour of the phenols present in EVOO and its total antioxidant capacity before and after the use of various culinary techniques such as deep frying, boiling (in a water/oil mixture (W/O) and sauteing, observing that the study parameters varied according to the variety of oil and the culinary technique used. Significant statistical differences were observed between the different varieties of EVOO according to the culinary technique used. But this was not the case with respect to polyphenol content, for which no statistically significant differences were observed among the different varieties of EVOO according to the culinary techniques employed (p > 0.05), except with the Arbequina variety (p < 0.05). With respect to the individual polyphenols - tyrosol, p-vainillin, vanillic acid, gallic acid, trans-caffeic acid, ferulic acid and luteolin - our analysis shows that although there were differences in content between raw EVOO and EVOO treated with each of the culinary techniques, these differences were not statistically significant (p > 0.05). There were significant losses of oleocanthal with the W/O boiling technique, but content increases were observed following sauteing and deep frying with respect to raw EVOO. Total antioxidant capacity presented a similar pattern in all samples, with increases after sauteing and decreases after W/O boiling and deep frying. ABTS was the most suitable technique for determining antioxidant capacity in EVOO. In short, the behaviour of the bioactive compounds in EVOO depends on the temperature and the cooking medium used.

The Antioxidant Properties of Selected Varieties of Pumpkin Fortified with Iodine in the Form of Potassium Iodide and Potassium Iodate

This study aimed to investigate the use of selected pumpkin varieties as carriers of potassium iodide (KI) and potassium iodate (KIO₃) at different concentrations (2.3, 0.23, and 0.023 mg/100 g). It was hypothesized that the concentrations and form of iodine fortification in pumpkins affect the antioxidant activity of pumpkins. The results showed a high recovery of the introduced iodine in all pumpkin varieties after drying, as well as high iodine stability during storage, especially for KIO₃. However, statistical analysis confirmed a relationship between the forms and concentration of iodine and the ABTS cation radical and the DPPH radical test results. In the systems with iodine concentration at 0.023 and 0.23 mg/100 g, the antioxidant activity did not change. However, for all pumpkin varieties fortified with a KIO₃ concentration at 3.9 mg/100 g (2.3 mg/100 g of iodine), a statistically significant decrease in free-radical scavenging was confirmed. Therefore, for maximum effectiveness in pumpkin's free-radical scavenging indices, it is suggested to introduce iodine in the form of KI and KIO₃, but in controlled concentrations. However, KIO₃ should be added at a maximum amount of 0.39 mg/100 g.

Preferences for dietary oils and fats in cooking and food preparation methods: a cross-sectional analysis of Australian adults

Dietary oils and fats contain different fatty acid compositions that are associated with cardiometabolic disease risk. Despite their influence on disease outcomes, the types of dietary oils and fats predominately used in Australian households remain unknown. The aim of this study was to investigate the use of dietary oils and fats in cooking and food preparation in Australia. Adults living in Australia completed a cross-sectional online survey outlining their current household oil and fat use from July to December 2021. The survey was disseminated via social media platforms and included questions about the types of dietary oils and fats used for different cooking methods and the perceived motivators for choosing the main household oil. A total of 1248 participants responded to the survey. Participants were mostly female (91·6 %) aged between 25 and 44 years (56·7 %). The majority of participants (84·5 %) reported using some form of olive oil as their main source of oil for cooking and food preparation. Almost two-thirds of the sample (65·4 %) reported using extra virgin olive oil (EVOO), mainly in raw food preparation (71·5 %) or savoury baking and roasting (58 %). Fewer households reported using rice bran oil (4·6 %), canola oil (4·3 %) and vegetable oil (1·8 %). Almost half of all participants (49·6 %) identified perceived health benefits as the primary motivating factor for their main choice of oil, followed by sensory preference (46·7 %), versatility (10·2 %) and convenience (8·8 %). Australian adults frequently use olive oil, specifically EVOO, as the main oil for cooking and food preparation in the household.

Extra Virgin Olive Oil and Cardiovascular Protection in Chronic Kidney Disease

The high mortality related to chronic kidney disease (CKD) is not only due to the disease itself; in fact, CKD also represents an important risk factor for cardiovascular (CV) morbidity and mortality. Among the functional foods that seems to have cardioprotective action, extra virgin olive oil (EVOO) plays a pivotal health-promoting role. The aim of this study was to evaluate the possible cardioprotective effects of an EVOO containing a very high content (>900 ppm) of minor phenolic compounds (MPCs). The selected EVOO was analyzed by HPLC-DAD-MS to establish the MPC content. The Olea extract obtained from the selected EVOO was tested against the RAW 264.7 cell line in order to investigate its anti-inflammatory activity. We enrolled 40 CKD patients under conservative therapy for in vivo clinical testing. All CKD patients consumed 40 mL/day of raw EVOO for 9 weeks (T1). At baseline (T0) and at T1, we monitored the patients’ blood and urinary parameters. The patients’ body composition was assessed using bioelectrical impedance analysis and the carotid intima-media thickness (CIMT) using ultrasound imaging. At T1, we observed a decrease in inflammatory parameters, CIMT, and oxidative stress biomarkers. We also noticed improvements in lipid and purine metabolism, atherogenic indices, and body composition. Thus, this study highlighted the cardioprotective action of EVOO in nephropathic patients.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

A Review of the Effects of Olive Oil-Cooking on Phenolic Compounds

The fate of phenolic compounds in oil and food during cooking vary according to the type of cooking. From a nutritional point of view, reviews largely suggest a preference for using extra-virgin olive oil at a low temperature for a short time, except for frying and microwaving, for which there appears to be no significant advantages compared to olive oil. However, due to the poorly pertinent use of terminology, the different protocols adopted in studies aimed at the same objective, the different type and quality of oils used in experiments, and the different quality and quantity of PC present in the used oils and in the studied vegetables, the evidence available is mainly contradictory. This review tries to reanalyse the main experimental reports on the fate, accessibility and bioavailability of phenolic compounds in cooking oils and cooked vegetables, by considering different cooking techniques and types of oil and foods, and distinguishing experimental findings obtained using oil alone from those in combination with vegetables. The re-analysis indicates that incomplete and contradictory observations have been published in the last few years and suggests that further research is necessary to clarify the impact of cooking techniques on the phenolic compounds in oil and vegetables during cooking, especially when considering their nutritional properties.

Migration of Avocado Virgin Oil Functional Compounds during Domestic Cooking of Eggplant

Avocado virgin oil (AVO) was used during eggplant deep-frying, boil, and boil in a water-oil mixture (W/O). There were measured the contents of moisture, dry matter, fat, total (TPC) and ten individual phenols, antioxidant activity (ABTS and DPPH), and total sterols; as well as the profiles of eight fatty acids and fourteen sterols/stanols. The values of raw and processed foods were compared and studied with multivariate analysis. The antioxidant capacity of AVO lowered after deep frying but augmented in eggplant and water after all treatments. The TPC was steady in AVO and raised in fried eggplant. Thermal treatments added to the initial profiles of the AVO, eggplant and water, nine, eight, and four phenols, respectively. Percentages of the main fatty acids (oleic, palmitic and linoleic), and sterols (β-sitosterol, campesterol, and Δ5-avenasterol), remained unchanged between the raw and treated AVO; and the lipidic fractions from processed eggplant. Cooking leads to the movement of hydrophilic and lipophilic functional compounds between AVO, eggplant and water. Migration of sterols and unsaturated fatty acids from AVO to eggplant during deep frying and W/O boiling improved the functional properties of eggplant by adding the high biological value lipophilic fraction to the naturally occurring polyphenols.

New vacuum cooking techniques with extra-virgin olive oil show a better phytochemical profile than traditional cooking methods: A foodomics study

In this work, the major changes in extra-virgin olive oil (EVOO) composition during cooking were assessed. A foodomics approach based on both metabolomics and lipidomics was used to evaluate the impact of six different cooking techniques, three traditional and three more innovative (Crock-pot®, Roner® and Gastrovac®), and the effect of temperature and cooking time. The lipophilic and hydrophilic fractions of EVOO that underwent different cooking processes were characterized by untargeted high-resolution mass spectrometry approaches. Multivariate statistics were used to unravel the differences in chemical signatures. The different cooking methods resulted in broadly different phytochemical profiles, arising from thermally driven reactions accounting for hydrolysis, synthesis, and oxidation processes. The innovative cooking techniques marginally altered the phytochemical profile of EVOO, whereas sauteing was the cooking method determining the most distinctive profile. Conventional cooking methods (oven, pan-frying, and deep-frying) produced more oxidation products (epoxy- and hydroxy-derivatives of lipids) and markedly induced degradation processes.

A comprehensive review on different classes of polyphenolic compounds present in edible oils

Edible oils are used as a frying medium and in the preparation of several food products. They are mainly constituting triacylglycerols as major components, while other compounds are classified as minor constituents, which include polyphenols. This class of compounds plays an important role in the thermal stability and quality attributes of the finished industrial food products. In addition to other antioxidants, the desired thermal stability of edible is achieved by either fortification or mixing of edible oils. This comprehensive review was therefore aimed to review the different classes of polyphenolic compounds present in commonly consumed edible oils. The edible oils reviewed include soybean, olive, rapeseed, canola, sunflower, flaxseed, sesame, cottonseed, palm, almond, peanut, chestnut, coconut, and hazelnut oils. The identified classes of polyphenolic compounds such as simple phenols, hydroxybenzoic acids, phenylethanoids, hydroxycinnamic acid, esters of hydroxycinnamic acids, coumarins & chromans, stilbenes, flavonoids, anthocyanins, and lignans were discussed. It was observed that a single edible from different origins showed the varied composition of the different classes of phenolic compounds. Among the oils, soybean, sunflower, olive, and brassica oils received higher attention in terms of polyphenol composition. Some classes of phenolic compounds were either not reported or absent in one edible oil, while present in others. Among the different classes of phenolics, hydroxybenzoic acids, hydroxycinnamic acid and flavonoids were the most widely present compounds. Phenolic compounds in edible oils possess several health benefits such as antioxidant, antibacterial, anti-viral, anti-inflammatory, anti-tumour, antioxidants, cardioprotective, neuroprotective, anti-diabetic properties and anti-obesity.

Evaluation of Chemical and Nutritional Changes in Chips, Chicken Nuggets, and Broccoli after Deep-Frying with Extra Virgin Olive Oil, Canola, and Grapeseed Oils

The aim of this study was to assess the food nutritional profiles of potato chips, chicken nuggets, and broccoli and their palatability after deep-frying with different oils. The trials consisted of 4 cycles of deep-frying at 180°C for 4 minutes using extra virgin olive oil (EVOO), canola, and grapeseed oils. Samples of food and oils were taken untreated and after the treatments for sensorial and chemical analysis. EVOO and canola oil deep-fried food were preferred by their colour, but canola fried food was disliked because of its flavour. Results showed that there is a transference between food and oils regarding fatty acid profile and antioxidant content as well as trans fatty acids (TFAs) and polar compounds (PCs). All food presented more antioxidants and monounsaturated fatty acids after having been cooked with EVOO than after cooking with canola and grapeseed oils. Highest PCs in food were found when using canola oil and grapeseed oils. EVOO was shown to decrease the PCs in chips and chicken nuggets. PCs were not detected in raw broccoli, and broccoli cooked in EVOO showed the lowest PCs content. Canola and grapeseed oils increased the TFAs in food, whereas EVOO decreased the TFAs in the chips and maintained the initial TFAs levels in chicken nuggets and broccoli. This study shows that EVOO improves the nutritional profile of the food when compared with canola and grapeseed oils when deep-frying without any negative impact on palatability or appearance.

The Impact of Formulation on the Content of Phenolic Compounds in Snacks Enriched with Dracocephalum moldavica L. Seeds: Introduction to Receiving a New Functional Food Product

A new type of multigrain snack has been designed containing varied additions of Moldavian dragonhead (Dracocephalum moldavica L.) seeds. The antioxidant properties and the general health benefits of this plant material have already been widely acknowledged. The research discussed herein aimed to investigate the influence of the formulation and expansion method (frying) on the content of polyphenolic compounds, individual phenolic acids, and antiradical properties of innovative snacks enriched with dragonhead seeds. The highest content of polyphenols (0.685 mg GAE/mL), free phenolic acids (47.052 µg/g of dry matter), and highest radical scavenging activity (96.23% towards DPPH) were found in the fried snacks enriched with 22% of seeds. In these samples, 11 phenolic acids were detected. Strong positive correlations were seen between the addition of dragonhead and the polyphenol content (r = 0.989) and between the quantity of the enriching additive and the content of free phenolic acids (r = 0.953). The research has shown that such innovative snacks have the potential to supply health-benefiting free phenolic acids, e.g., salicylic, isoferulic, ferulic, p-coumaric, vanillic. Our studies provide an introduction to the development of a new range of functional foods.

Study of the phenolic compound profile and antioxidant activity of human milk from Spanish women at different stages of lactation: A comparison with infant formulas

Human milk (HM) has been proven to have important and essential antioxidant properties to counteract infant susceptibility to oxidative stress. Phenolic compounds are secondary metabolites which come from plants and are potent natural antioxidants. The ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method used in the present study allowed the quantification of 26 phenolic compounds (ten hydroxybenzoic acids, seven hydroxycinnamic acids, four flavonoids, three hydroxybenzaldehydes and two other polyphenols) in HM samples at different stages of lactation (colostrum, transitional milk and mature milk) and infant formulas (IF). Many of the phenolic compounds identified have been reported to be present in HM for the first time. The total phenolic compound content (TPC) was quantified using the Folin assay and the antioxidant activity (AC) was evaluated with the DPPH, ABTS and FRAP assays. Significant differences were evidenced between HM and IF. HM from mothers with an adherence to a Mediterranean diet contained twice as many individual phenolic compounds as infant formulas, with a higher proportion of hydroxybenzoic acids. Conversely, IF showed a higher proportion of hydroxycinnamic acids. Overall, the antioxidant activity of HM showed small variations during lactation.

Differences in the Phenolic Profile by UPLC Coupled to High Resolution Mass Spectrometry and Antioxidant Capacity of Two Diospyros kaki Varieties

BACKGROUND

phenolic compounds are bioactive chemical species derived from fruits and vegetables, with a plethora of healthy properties. In recent years, there has been a growing interest in persimmon (Diospyros kaki L.f.) due to the presence of many different classes of phenolic compounds. However, the analysis of individual phenolic compounds is difficult due to matrix interferences.

METHODS

the aim of this research was the evaluation of individual phenolic compounds and antioxidant capacity of the pulp of two varieties of persimmon (Rojo Brillante and Triumph) by an improved extraction procedure together with a UPLC-Q-TOF-MS platform.

RESULTS

the phenolic compounds composition of persimmon was characterized by the presence of hydroxybenzoic and hydroxycinnamic acids, hydroxybenzaldehydes, dihydrochalcones, tyrosols, flavanols, flavanones, and flavonols. A total of 31 compounds were identified and 17 compounds were quantified. Gallic acid was the predominant phenolic compounds found in the Rojo Brillante variety (0.953 mg/100 g) whereas the concentration of p-hydroxybenzoic acid was higher in the Triumph option (0.119 mg/100 g).

CONCLUSIONS

the results showed that the Rojo Brillante variety had higher quantities of phenolic compounds than the Triumph example. These data could be used as reference in future phenolic compound databases when individual health effects of phenolic compounds become available.

Quantification of Cooking Method Effect on COP Content in Meat Types Using Triple Quadrupole GC-MS/MS

A diet containing cholesterol is an essential component of biological function; however, cholesterol oxidation products (COPs) remain a major public health concern. This study investigated the effects of cooking methods (boiling and frying) on the production levels of COPs in processed foods. Samples, as represented by minced beef, chicken sausages, and fish fillets, were subjected to different cooking methods followed by COP extraction using a saponification method. Then, six common COPs, 5α-cholest, α-epoxy, β-epoxy, 25-HC, triol, and 7-keto, were quantified by triple quadrupole gas chromatography-mass spectrometry (GS-MS/MS). A significantly high number of COPs were detected in minced meat, of which 7-keto and triol were detected as major oxidation products, followed by chicken sausages and fish fillets (p ≤ 0.05). Compared to boiling, frying generated significantly more COPs, specifically triol (0.001-0.004 mg/kg) and 7-keto (0.001-0.200 mg/kg), in all samples. Interestingly, cholesterol level was found to be slightly (but not significantly) decreased in heat-treated samples due to oxidation during cooking, producing a higher number of COPs. Notably, the fish fillets were found to produce the fewest COPs due to the presence of a low amount of cholesterol and unsaturated fatty acids. In conclusion, adapting boiling as a way of cooking and choosing the right type of meat could serve to reduce COPs in processed foods.

Green Route for the Isolation and Purification of Hyrdoxytyrosol, Tyrosol, Oleacein and Oleocanthal from Extra Virgin Olive Oil

Extra virgin olive oil (EVOO) phenols represent a significant part of the intake of antioxidants and bioactive compounds in the Mediterranean diet. In particular, hydroxytyrosol (HTyr), tyrosol (Tyr), and the secoiridoids oleacein and oleocanthal play central roles as anti-inflammatory, neuro-protective and anti-cancer agents. These compounds cannot be easily obtained via chemical synthesis, and their isolation and purification from EVOO is cumbersome. Indeed, both processes involve the use of large volumes of organic solvents, hazardous reagents and several chromatographic steps. In this work we propose a novel optimized procedure for the green extraction, isolation and purification of HTyr, Tyr, oleacein and oleocanthal directly from EVOO, by using a Natural Deep Eutectic Solvent (NaDES) as an extracting phase, coupled with preparative high-performance liquid chromatography. This purification method allows the total recovery of the four components as single pure compounds directly from EVOO, in a rapid, economic and ecologically sustainable way, which utilizes biocompatible reagents and strongly limits the use or generation of hazardous substances.

Metabolic and functional interplay between gut microbiota and fat-soluble vitamins

Gut microbiota is a complex ecosystem seen as an extension of human genome. It represents a major metabolic interface of interaction with food components and xenobiotics in the gastrointestinal (GI) environment. In this context, the advent of modern bacterial genome sequencing technology has enabled the identification of dietary nutrients as key determinants of gut microbial ecosystem able to modulate the host-microbiome symbiotic relationship and its effects on human health. This article provides a literature review on functional and molecular interactions between a specific group of lipids and essential nutrients, e.g., fat-soluble vitamins (FSVs), and the gut microbiota. A two-way relationship appears to emerge from the available literature with important effects on human metabolism, nutrition, GI physiology and immune function. First, FSV directly or indirectly modify the microbial composition involving for example immune system-mediated and/or metabolic mechanisms of bacterial growth or inhibition. Second, the gut microbiota influences at different levels the synthesis, metabolism and transport of FSV including their bioactive metabolites that are either introduced with the diet or released in the gut via entero-hepatic circulation. A better understanding of these interactions, and of their impact on intestinal and metabolic homeostasis, will be pivotal to design new and more efficient strategies of disease prevention and therapy, and personalized nutrition.

Domestic Sautéing with EVOO: Change in the Phenolic Profile

(1) Background: The health benefits of extra-virgin olive oil (EVOO), a key component of the Mediterranean diet, are attributed to its polyphenol profile. EVOO is often consumed cooked, and this process may degrade and transform polyphenols. (2) Methods: In this work, we determined how temperature, time, and the interaction between them affects the EVOO polyphenolic profile during a domestic pan-frying process, simulating the cooking conditions of a home kitchen, without the control of light or oxygen. Applying a 22 full factorial design experiment, "Hojiblanca" EVOO was processed at two temperatures (120 °C and 170 °C) either for a short time or a long time, mimicking a domestic process, and polyphenol content was analyzed by UPLC-ESI-QqQ-MS/MS. (3) Results: Temperature degraded the polyphenols of EVOO during the sauté cooking process, whereas time had an effect on some individual phenols, such as hydroxytyrosol, but not on the total phenol content. The polyphenol content decreased by 40% at 120 °C and 75% at 170 °C compared to raw EVOO. (4) Conclusions: Cooked EVOO still meets the parameters of the EU's health claim.