Olive Oil Research Articles

Impact of supplementation with iron–folic acid (IFA) and vitamin D3 compared with IFA alone on haemoglobin levels in elderly people with mild-to-moderate anaemia: protocol for the double-blind, randomised, placebo-controlled Iron and vitamin D trial in Elderly Anemia (IDEA)

IntroductionAnaemia in the elderly is often difficult to treat with iron supplementation alone as prevalence of anaemia of chronic disease (ACD) alone or mixed with iron-deficiency anaemia (IDA) is high...

Phenotypic and genetic characterization of a lipolytic Ralstonia mannitolilytica isolate from petroleum-contaminated soil in Iraq.

Lipases play a crucial role in various industrial applications, and microbial lipases, particularly those from bacteria, possess significant properties. With increasing concerns about the environmental and health impacts of hydrocarbons from pipelines and refineries, there is a growing need to mitigate the risks associated with these compounds. In this study, 40 bacterial isolates were recovered from contaminated soil samples collected from multiple refineries across Iraq. Using the Vitek system, bacterial isolates were identified up to the species level, revealing that only 12 isolates exhibited lipase-producing capabilities. Among the lipase-producing isolates, Ralstonia mannitolilytica demonstrated the highest extracellular lipase activity, as determined by an olive oil plate assay supplemented with rhodamine B. Confirmation of the species identity was achieved through 16S rRNA gene sequencing, with the obtained sequence deposited under accession number LC772176.1. Further sequence analysis revealed single nucleotide polymorphisms (SNPs) in the genome of Ralstonia mannitolilytica strain H230303-10_N19_7x_R2 (CP011257.1, positions 1,311,102 and 1,311,457). Additionally, the presence of the lipase gene was confirmed through amplification and sequencing using a thermocycler PCR. Sequence analysis of the gene, aligned using Geneious Prime software, identified SNPs (CP010799, CP049132, AY364601, CP011257, and CP023537), and a phylogenetic tree was constructed based on genetic characterization. Our findings highlight the potential of Ralstonia mannitolilytica as a promising candidate for lipase production and contribute to our understanding of its genetic diversity and biotechnological applications in hydrocarbon degradation and industrial processes.

The effect of hydrosol types on phytochemical properties, phenolic compounds, fatty acid profiles and sensory properties of ‘Ayvalık’ olive fruits fermented in few spice hydrosols

SummaryIn this study, the changes in oil content, bioactive components, radical scavenging activity, phenolic profiles, fatty acid components and sensory characteristics of ‘Ayvalık’ olive fruits fermented in brine thyme, sage and rosemary hydrosols were investigated. Total carotenoid and total phenolic results of olives were recorded between 0.02 (thyme hydrosol) and 0.24 μg g−1 (control (only brine 10%)) to 213.92 (rosemary hydrosol) and 432.54 mg GAE per 100 g (fresh ‘Ayvalık’ olive), respectively. Total flavonoids of olive fruits fermented in different hydrosols were reported between 755.87 mg per 100 g (rosemary hydrosol) and 1404.76 mg per 100 g (fresh ‘Ayvalık’ olive). Radical scavenging capacity of fermented ‘Ayvalık’ olive fruits was reported between 10.20 (control) and 10.55 mmol kg−1 (rosemary hydrosol). Verbascoside results of fresh and fermented ‘Ayvalık’ olive fruits in brine and hydrosols were identified between 107.00 mg per 100 g (sage hydrosol) and 167.20 mg per 100 g (fresh ‘Ayvalık’ olive). Oleic and linoleic acid values of olive oils changed to be between 67.07% (rosemary hydrosol) and 68.71% (control) to 10.89% (control) and 11.86% (rosemary hydrosol), respectively. Overall, ‘Ayvalık’ olive fruit fermented in brine was most appreciated by the panellists, followed in descending order by olives fermented in thyme, sage, and rosemary hydrosols.

Mechanical properties, sustained release, and oxygen scavenging properties of nanocomposite films loaded with bimetallic nanoparticles (Fe2O3/TiO2) in extra virgin olive oil.

The aim of this study was the synthesis of bimetallic nanoparticles based on Fe2O3/TiO2 and its use in the poly(lactic acid) (PLA) films as an oxygen scavenger in extra virgin olive oil (EVOO) packaging. Bimetallic nanocomposites were prepared by two different precipitation methods (precipitation with ammonia and sodium hydroxide). The characteristics of bimetallic nanoparticles precipitated with sodium hydroxide (Na-Ti0.01Fe0.048O0.08) and bimetallic nanoparticles precipitated with ammonia (NH-Ti0.01Fe0.022O0.09) were compared. Relative amounts of elements in bimetallic nanocomposites and their morphological characteristics were determined using field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometer. Porosity volume and surface area of bimetallic nanoparticles were calculated using adsorption-desorption isotherms and the Brunauer-Emmett-Teller method. The formation/characterization of bimetallic nanoparticles and their location in the matrix of PLA-based nanocomposite film was studied using X-ray diffraction and Fourier transform infrared. In nanocomposite films based on PLA, bimetallic nanoparticles lead to better oxidative stability (peroxide value, p-anisidine index, K232, and K270) of the EVOO and oxygen scavenging during storage compared to free nanoparticles. Mechanical properties of nanocomposite films were improved due to bimetallic nanoparticles, which were better for Na-Ti0.01Fe0.048O0.08. In vitro release modeling of the bimetallic nanoparticles in EVOO proved that Fickian diffusion is the dominant mechanism, and the Peleg model was the best description of the release behavior of nanoparticles.

The frequency of selective functional foods consumption is related to improved anthropometric obesity indices: A cross-sectional study in Greek and Cyprian adults

Background: Obesity remains a public health problem. Recent, novel strategies suggest thefrequent inclusion of functional foods for better management of adiposity markers and obesityprevention. Numerous epidemiological and clinical studies demonstrate specific naturalfunctional foods of the Mediterranean Diet and innovative processed foods, enhanced withbioactive compounds, that they may present a possible beneficial role on this approach. Methods: In this cross-sectional epidemiological study, 319 Greeks and Cyprians, aged 18-75years were voluntary recruited in personal interviews. A validated Functional Food Frequency ofConsumption (FFFQ) was filled out, recording the frequency of selective functional foodsconsumption, following by anthropometric and body composition evaluations. Data collectionand statistical analysis were conducted, to assess the possible association of functional foodsfrequency of consumption with adiposity markers. Results: Olive oil is a main part of the daily diet of the representative sample of Greek andCyprian population and its frequency of intake was inversely related to body weight, taking intoaccount the lifestyle pattern and social parameters. Considering general habits andsociodemographic characteristics, Body Mass Index (BMI) was directly associated with thefrequency of consumption of split peas, turmeric, cinnamon, honey, whole wheat- and gluten-free pasta, as well as of gluten-free and enhanced bakeries. These functional food groups areconsumed by majority in a monthly basis, except of honey which is weekly consumed by themajority of the study population. Conclusion: The results suggest that the daily intake of olive oil, as the main characteristic ofMediterranean Diet, may be effective on body weight management. The frequency rise ofspecific spices, honey, functional pasta and bakeries consumption, may lead to increases inmarkers of adiposity. Further research is needed to safely conclude to these claims and theimplementation of nutritional treatment programs with functional foods may prove effective inthe prevention and management of obesity. Keywords: epidemiological study; functional foods; frequency of consumption; obesity;adiposity association; Greeks; Cyprians

Fourier transform infrared spectroscopy coupled with chemometrics for the monitoring of virgin olive oil quality during storage up to 18 months

Fourier transform infrared spectroscopy coupled with chemometrics for the monitoring of virgin olive oil quality during storage up to 18 months

Teaching fluorescence of plants & algae in physics class to address climate change

In physics classes and general education classes, teaching the concept of fluorescence can be challenging, and it may seem too theoretical for some students. A short YouTube video titled ‘Seeing Photosynthesis from Space’ displays a global map of photosynthesis, and this is an excellent, attention-getting way to visually introduce fluorescence to students and also to address climate change. Therefore, three hands-on activities were designed using spinach chlorophyll ethanol extract and olive oil to observe the fluorescence emission; in addition, a smartphone spectrophotometer was employed to observe the spectrum of the emission. The class also addressed the issue of global warming because the absorption of CO2 by plants and algae is decreasing, which may cause serious climate change.

The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

Trends and persistence in global olive oil prices after COVID-19

Trends and persistence in global olive oil prices after COVID-19

Impact of olive leaves powder addition on extra virgin olive oil: Sensory, quality, nutritional and volatile compounds implications

AbstractOlive leaves currently represent a waste from olive oil industry that can be reused as source of polyphenols and other compounds. The objective of this study was to test whether incorporation of olive leaf powder directly in olive oils can enhance and modify its chemical‐sensory quality. Thus, leaves from cultivar “Koroneiki” were washed, sanitized, dried (37–40°C for 48 h) and milled until obtaining a powder that was added to “Arbequina” and “Koroneiki” extra virgin olive oils, at 1% and 3%. The oils were stored in dark conditions at room temperature and samples were checked after 0, 3, 6 and 12 months. The quality parameters, sensory properties, and nutrition quality (total phenolics, antioxidant, oleuropein and alpha‐tocopherol) were evaluated. The olive leaves affected quality and chemical composition, mainly increasing resistance to oxidation, which was not verified in samples without leaves addition. The incorporation of leaves powder significantly increased the contents of C6‐C5 alcohols/aldehydes, intensity of the green fruity and bitter, also artichoke, herbs, tomato leaf, olive leaves and banana peels sensations.

Sensory and physicochemical characteristics of Uruguayan picual olive oil obtained from olives with different ripening indexes

The sensory and physicochemical characteristics of olive oil will be mainly influenced by the agronomic conditions of the crop and harvest. Therefore, the results cannot be extrapolated from one region to another. On the contrary, the ripening index (RI) is a factor that can influence the quality of the oils obtained. Picual is one of the four most important olive varieties from Uruguay. This work studied how ripening influences the sensory and physicochemical characteristics of the extra virgin olive oil extracted from the Picual variety olives harvested in Uruguay. A total of 19 samples of olive oils extracted in the Abencor System pilot plant were analyzed. They were obtained from green, medium, and ripened olives from two different harvests (2021 and 2022). All the studied pastes were considered “difficult” due to a high moisture content of over 55%. This was reflected in the low yields of extraction which did not exceed 12.9%. All the oils obtained were characterized as extra virgin from a sensory and physicochemical point of view. Their content of total phenols and oleic acid allows defining Uruguayan Picual oils as “high in total phenols” and “high in oleic acid,” respectively. They were sensory characterized as oils with fruity medium, bitter medium, and pungent medium and green, tomato, banana, and dry fruit aromatic notes. When olives increased ripening, the fruity, bitter, and pungent of the oils and phenol and oleic contents and the oleic/linoleic ratio decreased, and the yield was not modified. This is what makes the Uruguayan olive oil of the Picual variety ideal to be harvested with low RIs.  

Adaptation Mechanisms of Olive Tree under Drought Stress: The Potential of Modern Omics Approaches

Olive (Olea europaea L.) is a crop of enormous economic and cultural importance. Over the years, the worldwide production of olive oil has been decreasing due to various biotic and abiotic factors. The current drop in olive oil production resulting from climate change raises concerns regarding the fulfillment of our daily demand for olive oil and has led to a significant increase in market prices. In the future, there will be a higher chance that we will face a severe shortage of olive oil, which could harm both the economic sector and the food supply. As olive groves cover more than 5 million hectares in the European Union alone, the need to preserve the crop in the context of extreme climatic events is imperative. As drought is considered one of the most limiting factors in agriculture, drought-resistant varieties and sustainable irrigation strategies are being developed to mitigate the impact of drought on crop productivity and secure the future supply of olive oil. This review focuses on recently gained insights into drought stress in olive trees through omics and phenomics approaches to unravelling mechanisms that may lead to developing new varieties that are tolerant against drought elicited by changes in growing systems.

Normal fat intake with high MUFA content and an appropriate SFA/MUFA/PUFA ratio improved the health of rats

AbstractThe quantity and quality of dietary fats have a significant impact on human health. This study aimed to investigate the effects of different cooking oils (olive oil (OO), soybean oil (SO), and blended oil (BO)) on growth, glucolipid metabolism, inflammation, and oxidative stress of rats fed normal and high‐fat diets. The results showed that the OO‐fed group had lower concentrations of serum triglyceride (TG), low‐density lipoprotein cholesterol (LDL‐C), malondialdehyde (MDA), oxidized LDL‐C (ox‐LDL‐C), and serum total cholesterol (TC) than the normal‐fat SO‐fed group, and rats in the BO‐fed group had lower values of serum interleukin‐6 (IL‐6), high‐sensitivity C‐reactive protein (hs‐CRP), tumor necrosis factor (TNF‐α), and nonesterified fatty acids (NEFA) than the normal‐fat SO‐fed groups. However, higher serum glutathione peroxidase (GSH‐Px) activity was observed in the OO‐fed group, while those fed with BO had higher serum superoxide dismutase (SOD) and GSH‐Px activities. Generally, most health‐beneficial fatty acid profiles have a high content of monounsaturated fatty acids (MUFAs), an appropriate saturated fatty acid (SFA)/MUFA/poly unsaturated fatty acid (PUFA) ratio, and a low n‐6/n‐3 PUFA ratio, while diets contained a high content of fat is detrimental to health.

The Production of Bioactive Hydroxytyrosol in Fermented Beverages: The Role of Must Composition and a Genetically Modified Yeast Strain

Hydroxytyrosol (HT) is a well-known compound for its bioactive properties. It is naturally present in olives, olive oil, and wine. Its presence in wines is partly due to its production during alcoholic fermentation by yeast through a hydroxylation of tyrosol formed through the Ehrlich pathway. This work aims to explore the influence of yeast assimilable nitrogen (YAN) and glucose content as precursors of HT formation during alcoholic fermentation. Commercial Saccharomyces cerevisiae QA23 and its metabolically engineered strain were used to ferment synthetic must. Each strain was tested at two different YAN concentrations (210 and 300 mg L−1) and two glucose concentrations (100 and 240 g L−1). This work confirms that the less YAN and the more glucose, the higher the HT content, with fermentations carried out with the metabolically engineered strain being the ones with the highest HT content (0.6 mg L−1).

Dilation of Pregnant Rat Uterine Arteries with Phenols from Extra Virgin Olive Oil Is Endothelium-Dependent and Involves Calcium and Potassium Channels.

During pregnancy, uterine vasculature undergoes significant circumferential growth to increase uterine blood flow, vital for the growing feto-placental unit. However, this process is often compromised in conditions like maternal high blood pressure, particularly in preeclampsia (PE), leading to fetal growth impairment. Currently, there is no cure for PE, partly due to the adverse effects of anti-hypertensive drugs on maternal and fetal health. This study aimed to investigate the vasodilator effect of extra virgin olive oil (EVOO) phenols on the reproductive vasculature, potentially benefiting both mother and fetus. Isolated uterine arteries (UAs) from pregnant rats were tested with EVOO phenols in a pressurized myograph. To elucidate the underlying mechanisms, additional experiments were conducted with specific inhibitors: L-NAME/L-NNA (10-4 M) for nitric oxide synthases, ODQ (10-5 M) for guanylate cyclase, Verapamil (10-5 M) for the L-type calcium channel, Ryanodine (10-5 M) + 2-APB (3 × 10-5 M) for ryanodine and the inositol triphosphate receptors, respectively, and Paxilline (10-5 M) for the large-conductance calcium-activated potassium channel. The results indicated that EVOO-phenols activate Ca2+ signaling pathways, generating nitric oxide, inducing vasodilation via cGMP and BKCa2+ signals in smooth muscle cells. This study suggests the potential use of EVOO phenols to prevent utero-placental blood flow restriction, offering a promising avenue for managing PE.

Healthy Diets and Lifestyles in the World: Mediterranean and Blue Zone People Live Longer. Special Focus on Gut Microbiota and Some Food Components.

Longevity has been associated with healthy lifestyles, including some dietary regimens, such as the Mediterranean diet (MedDiet) and the Blue Zone (BZ) diets. MedDiet relies on a large consumption of fruit, vegetables, cereals, and extra-virgin olive oil, with less red meat and fat intake. Four major BZ have been recognized in the world, namely, Ogliastra in Sardinia (Italy), Ikaria (Greece), the Peninsula of Nicoya (Costa Rica), and Okinawa (Japan). Extreme longevity in these areas has been associated with correct lifestyles and dietary regimens. Fibers, polyphenols, beta-glucans, and unsaturated fatty acids represent the major constituents of both MedDiet and BZ diets, given their anti-inflammatory and antioxidant activities. Particularly, inhibition of the NF-kB pathway, with a reduced release of pro-inflammatory cytokines, and induction of T regulatory cells, with the production of the anti-inflammatory cytokine, interleukin- 10, are the main mechanisms that prevent or attenuate the "inflammaging." Notably, consistent physical activity, intense social interactions, and an optimistic attitude contribute to longevity in BZD areas. Commonalities and differences between MedDIet and BZ diets will be outlined, with special reference to microbiota and food components, which may contribute to longevity.

The design of natural hybrid biomaterial to promote osteogenic differentiation, collagen i and II expression and relief of musculoskeletal pains: Bone tissue-engineering applications (in-vitro and clinical studies)

This research aimed to fabricate a natural hybrid biomaterial and assess its physicochemical/biological properties to study the role of the therapeutic biomaterial in the growth of human monocytes, synoviocytes, chondrocytes, expression of type-I/II collagen, and osteogenic differentiation for bone tissue engineering applications, as well as to assess effects of bio-ointment derived from this biomaterial on relief of musculoskeletal pains. Hence, an oily formula [turmeric:ginger:chili pepper:rose oils (1:1:1:1w/w)] was mixed with the base oil [sesame:black seed:olive oils (1:0.4:0.6w/w)] in 3 wt ratios of 1:6(H1), 1.5:5.5(H2), and 2:5(H3). Accordingly, H2 indicated a better performance in cell growth and decrease of inflammatory mediators and led to the highest expression of osteoblastic genes of RUNX2, OCN, and OPN, as well as collagen I and II (COL1A1,COL2A) respectively 1.3-fold, 1.7-fold, and 1.4-fold, as well as %87 % and ∼ 60 % higher than H1, and ∼ 2-fold, 2.1-fold, and 3.4-fold, and ∼ 19 % and ∼ 16 % higher than H3. A clinical study on H2 was also performed on 50 patients with musculoskeletal pains. H2-based bio-ointment could relieve pain in less than 10 min for 40 % of patients and after 30 min from use for 35 %. Moreover, the analgesia period for 60 % and 36 % of patients lasted for longer than 3 h and between 2 h and 3 h, respectively. 76 % also stated that bio-ointment possesses stronger effects than other treatments along with moderate warming functions. Finally, although 6 % of patients reported mild effectiveness in pain relief, 92 % of users stated this therapeutic method has resulted in more effects on their pain relief and damaged organ performance recovery.

[Determination of six halogenated solvent residues in olive oil by headspace gas chromatography].

The residual amount of halogenated solvents in olive oil is an important indicator of its quality. The National Olive Oil Quality Standard GB/T 23347-2021 states that the residual amount of individual halogenated solvents in olive oil should be ≤0.1 mg/kg and that the total residual amount of halogenated solvents should be ≤0.2 mg/kg. COI/T.20/Doc. No. 8-1990, which was published by the International Olive Council, describes the standard method used for the determination of halogenated solvents in olive oil. Unfortunately, this method is cumbersome, has poor repeatability and low automation, and is unsuitable for the detection and analysis of residual halogenated solvents in large quantities of olive oil. At present, no national standard method for determining residual halogenated solvents in olive oil is available in China. Thus, developing simple, efficient, accurate, and stable methods for the determination of residual halogenated solvents in olive oil is imperative. In this paper, a method based on automatic headspace gas chromatography was established for the determination of residual halogenated solvents, namely, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, dibromochloromethane, tetrachloroethylene, and bromoform, in olive oil. The samples were processed as follows. After mixing, 2.00 g (accurate to 0.01 g) of the olive oil sample was added into a 20 mL headspace injection bottle and immediately sealed for headspace gas chromatography analysis. Blank virgin olive oil was used to prepare a standard working solution and the external standard method for quantification. The solvents used in the preparation of halogenated solvent standard intermediates were investigated and methanol was selected as a replacement for N,N-dimethylacetamide to prepare a halogenated solvent standard intermediate owing to its safety. The effects of different injection times (1, 2, 3, 4, 5, 6 s), equilibration temperatures (60, 70, 80, 90, 100, 110, 120 ℃), and equilibration times (4, 5, 8, 10, 20, 30, 40 min) of the headspace sampler on the detection of the residual amounts of the six halogenated solvents were investigated. The optimal injection time and equilibration temperature were 3 s and 90 ℃, respectively. The method demonstrated good analytical performance for the six halogenated solvents when the equilibration time was 30 min. A methodological study was conducted on the optimized method, and the results showed that the six halogenated solvents exhibited good linear relationships in the range of 0.002-0.200 mg/kg, with correlation coefficients of ≥0.9991. The limits of detection (LODs) and quantification (LOQs) of 1,1,1-trichloroethane and bromoform were 0.0006 and 0.002 mg/kg, respectively. The LODs and LOQs of chloroform, carbon tetrachloride, dibromochloromethane, and tetrachloroethylene were 0.0003 and 0.001 mg/kg, respectively. The average recoveries under different spiked levels were 85.53%-115.93%, and the relative standard deviations (n=6) were 1.11%-8.48%. The established method was used to analyze 13 olive oil samples available in the market. Although no halogenated solvents were detected in these samples, a limited number of samples does not represent all olive oils. Hence, monitoring residual halogenated solvents in olive oil remains necessary for its safe consumption. The LOQs of the method for the six halogenated solvents were significantly lower than that of the COI/T.20/Doc. No. 8-1990 standard method (0.02 mg/kg). In addition, the developed method can be conducted under short operation times with high precision and degree of automation as well as good accuracy. Thus, the proposed method is suitable for the determination and analysis of the residues of the six halogenated solvents in large batches of olive oil samples.

[Determination of 222 pesticide residues in olive oil by fully automatic QuEChERS pre-treatment instrument coupled with gas chromatography-quadrupole-time-of-flight mass spectrometry].

Pesticide residues may be present in olive oil because pesticides are applied to olive trees during their cultivation and growth for pest prevention and some of these pesticides are not easily degraded. Studies on pesticide residues in olive oil have mainly focused on the detection of single types of pesticide residues, and reports on the simultaneous detection of multiple pesticide residues are limited. At present, hundreds of pesticides with different polarities and chemical properties are used in practice. In this study, an analytical method based on fully automatic QuEChERS pretreatment instrument coupled with gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOF-MS) was established for the rapid determination of 222 pesticide residues in olive oil. The effects of acetonitrile acidification concentration, n-hexane volume, oscillation time, centrifugation temperature, and purification agent on the determination of the 222 pesticide residues were investigated. First, ions with good responses and no obvious interference were selected for quantification and characterization. The purification process was then developed by setting the parameters of the fully automatic QuEChERS pretreatment instrument to optimal values. The sample was extracted with acetonitrile containing 2% formic acid, and the supernatant was purified by centrifugation in a centrifuge tube containing 400 mg N-propylethylenediamine (PSA), 400 mg octadecylsilane-bonded silica gel (C18), and 1200 mg anhydrous magnesium sulfate. The purified solution was blown dry with nitrogen and then fixed with ethyl acetate for instrumental analysis. Finally, a matrix standard solution was used for quantification. The method was validated in terms of matrix effects, linear ranges, limits of detection (LODs) and quantification (LOQs), accuracies, and precisions. The results showed that 86.04% of the 222 pesticides had linear ranges of 0.02-2.00 μg/mL, 10.81% had linear ranges of 0.10-2.00 μg/mL, and 3.15% had linear ranges of 0.20-2.00 μg/mL. The pesticide residues showed good relationships within their respective linear ranges, and the correlation coefficients (R2) were greater than 0.99. The LODs of all tested pesticides ranged from 0.002 to 0.050 mg/kg, and their LOQs ranged from 0.007 to 0.167 mg/kg. Among the 222 pesticides determined, 170 pesticides had LOQs of 0.007 mg/kg while 21 pesticides had LOQs of 0.017 mg/kg. At the three spiked levels of 0.2, 0.5, and 0.8 mg/kg, 79.58% of all tested pesticides had average recoveries of 70%-120% while 65.92% had average recoveries of 80%-110%. In addition, 93.54% of all tested pesticides had relative standard deviations (RSDs, n=6)<10% while 98.35% had RSDs (n=6)<20%. The method was applied to 14 commercially available olive oil samples, and seven pesticides were detected in the range of 0.0044-0.0490 mg/kg. The residues of fenbuconazole, chlorpyrifos, and methoprene did not exceed the maximum limits stated in GB 2763-2021. The maximum residual limits of molinate, monolinuron, benalaxyl, and thiobencarb have not been established. The method utilizes the high mass resolution capability of TOF-MS, which can improve the detection throughput while ensuring good sensitivity. In addition, high-resolution and accurate mass measurements render the screening results more reliable, which is necessary for the high-throughput detection of pesticide residues. The use of a fully automatic QuEChERS instrument in the pretreatment step reduces personnel errors and labor costs, especially when a large number of samples must be processed, thereby offering significant advantages over other approaches. Moreover, the method is simple, rapid, sensitive, highly automatable, accurate, and precise. Thus, it meets requirements for the high-throughput detection of pesticide residues in olive oil and provides a reference for the development of detection methods for pesticide residues in other types of oils as well as the automatic pretreatment of complex matrices.

Pulsed electric field treatment improves the oil yield, quality, and antioxidant activity of virgin olive oil

Pulsed electric field (PEF) is an innovative technique used to assist in the extraction of vegetable oils. There has been no research on the effects of PEF on virgin olive oil (VOO) quality and antioxidant activity to date. The present study aimed to analyze the effects of PEF on oil yield, quality, and in vitro antioxidant activity of “Koroneiki” extra virgin olive oil. The results show that the PEF treatment increased the oil yield by 5.6%, but had no significant effect on the saponification value, K232, K270, and ∆K value of the VOO. PEF treatment reduced the oleic acid content by 3.12%, but had no significant effect on the content of palmitic acid, linoleic acid, linolenic acid, arachidonic acid, stearic acid, oleic acid, and palmitic acid. After PEF treatment, the levels of total phenolics, total flavonoids, and oleuropein increased by 7.6%, 18.3% and 76%, respectively. There was no significant effect on the levels of 4 phenolic acids (vanillic acid, p-coumaric acid, ferulic acid and cinnamic acid), 2 lignans (lignans and apigenin), hydroxytyrosol, and 3 pigments (lutein, demagnetized chlorophyll, and carotenoids). In addition, PEF treatment significantly increased the content of tocopherols, with α, β, γ, and δ tocopherols increasing by 9.8%, 10.7%, 13.6% and 38.4%, respectively. The free radical scavenging ability of DPPH and ABTS was also improved. In conclusion, the use of PEF significantly increased the yield of VOO oil as well as the levels of total phenolics, total flavonoids, oleuropein, tocopherol, and in vitro antioxidant activity.