The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay is widely used to determine the antioxidant activity of food products and extracts. However, the common DPPH• protocol uses a two-point measurement and ...does not give information about the kinetics of the reaction. A novel stoichio-kinetic model applied in this study monitors the consumption of DPPH• by common antioxidants following the second order reaction. The fitting of such decay yields the rate constant k1, which describes the main reaction between antioxidants and DPPH•, and the rate constant k2, which is attributed to a slower side reaction considering the products generated between the transient radicals (AO•) and another molecule of DPPH•. The model was first applied to antioxidant standards. Sinapic acid, Trolox and ascorbic and chlorogenic acids did not show any side reaction. Instead gallic, ferulic and caffeic acids achieved the best fitting with k2. The products of the side reaction for these compounds were confirmed and identified with high-resolution mass spectrometry. Finally, the kinetic model was applied to evaluate the antioxidant activity of eight herbal extracts. This study suggests a new kinetic approach to standardize the common DPPH• assay for the determination of antioxidant activity.
Hay milk is a traditional dairy product recently launched on the market. It is protected as "traditional specialty guaranteed" (TSG) and subjected to strict regulations. One of the most important ...restrictions is that the cow's feed ration must be free from silage. There is the need for analytical methods that can discriminate milk obtained from a feeding regime including silage. This study proposes two analytical approaches to assess the authenticity of hay milk. Hay milk and milk from cows fed either with maize or grass silage were analyzed by targeted GC-MS for cyclopropane fatty acid (dihydrosterculic acid, DHSA) detection, since this fatty acid is strictly related to the bacterial strains found in silage, and by HPLC-HRMS. The presence of DHSA was correlated to the presence of maize silage in the feed, whereas it was ambiguous with grass silage. HPLC-HRMS analysis resulted in the identification of 14 triacylglycerol biomarkers in milk. With the use of these biomarkers and multivariate statistical analysis, we were able to predict the use of maize and grass silage in the cow's diet with 100% recognition. Our findings suggest that the use of analytical approaches based on HRMS is a viable authentication method for hay milk.
As a widely consumed foodstuff, milk and dairy products are increasingly studied over the years. At the present time, milk profiling is used as a benchmark to assess the properties of milk. Modern ...biomolecular mass spectrometers have become invaluable to fully characterize the milk composition. This review reports the analysis of milk and its components using liquid chromatography coupled with mass spectrometry (LC–MS). LC–MS analysis as a whole will be discussed subdivided into the major constituents of milk, namely, lipids, proteins, sugars and the mineral fraction.
This work demonstrates the use of a triple detector for the screening of antioxidants in officinal plants. The triple detector consisted of a coulometric array (CAD), a diode array (DAD) and a mass ...spectrometer (MS) detector, which were connected to a HPLC system. DAD gave an overall profile of bioactive compounds. CAD allowed to select the most promising redox species and quantify their concentration based on the Faraday's law. Finally, MS was used for identification. The approach was applied to screen the main antioxidants in 19 officinal plants. Furthermore, the electron transfer properties obtained by CAD were highly correlated with the results of classical DPPH (r = 0.80), FRAP (r = 0.87) and ORAC (r = 0.90) assays and, thus, could be used to predict the antioxidant capacity of plant extracts by stepwise linear regression models (R2 = 0.99). Overall, the triple detector system allows a comprehensive approach to screen and characterize the antioxidant compounds in natural plant extracts.
•Triple detector was used to detect antioxidant compounds in 19 officinal plants.•Triple detector was for the first time used for screening of antioxidants.•The quantification can be achieved with the application of the Faraday's law.•The main compounds were identified by high resolution mass spectrometry.•The correlation between coulometric array detector and antioxidant capacity is high.
This study aimed to investigate the application of isothermal calorimetry as technique for monitoring microparticles oxidation produced by particles from gas saturation solution (PGSS) technique. ...Microparticles were obtained by mixing linseed oil (9.1 g/100 g) with glycerol stearate (90.9 g/100 g). The process was carried out at 10 MPa, 55 °C for 30 min. To enhance microparticles oxidative stability, β-carotene was also added to the formulation (0.4 up to 1.6 mg/g of oil). The results showed that the fatty acid profile of the oil did not change after the encapsulation process. From the isothermal calorimetry traces, it was possible to determine the induction time (τIC) and the rates of oxidation during the inhibited (Rinh) and uninhibited (Runi) period. The microencapsulation by PGSS significantly (p < 0.05) increased τIC values of microparticles compared to the bulk oil, which resulted equal to 32 ± 1 × 104 s and 10.2 ± 2 × 104 s, respectively. On the other side, Rinh significantly decreased confirming the higher microparticles oxidative stability. β-carotene addition enhanced the oxidative stability proportionally to the concentration of the added antioxidant. At the end of the oxidation, the 3-OH-beta-apo-11-carotenal and the 3-OH-beta-apo-carotenone compounds derived from β-carotene degradation were detected.
•Isothermal calorimetry monitored microcapsules rich in unsaturated fatty acids.•The kinetics parameters were evaluated from the calorimetric traces.•β-carotene addition improved microcapsules oxidative stability.
This work aims to determine the antioxidant and prooxidant activity of spent coffee extracts obtained with (1) a low-pressure (LP) extraction with ethanol and (2) a subcritical fluid (SF) extraction ...with carbon dioxide and ethanol as co-solvent. The antioxidant capacity of both extracts was measured by two calorimetry-based approaches. The first assessed the capacity of the extracts to inhibit the lipid oxidation of a standard solution of linseed oil. The second measured the capacity of the extracts to inhibit the radical decomposition of AIBN, a free radical generator. Both approaches showed that LP extracts had a higher antioxidant capacity than SF extracts. However, when SF extracts were further purified with ethanol, the resulting sub-fraction showed an antioxidant capacity comparable to that of LP extracts. Conversely, when SF extracts were purified with hexane, the resulting sub-fraction exhibited a prooxidative capacity, either speeding-up the oxidation of linseed oil and the decomposition rate of AIBN. Such prooxidative capacity was explained with the high content of unsaturated fatty acids contained in the hexane sub-fraction. Overall, this work showed that LP technique provided an extract with high antioxidant activity. Moreover, the results indicated that SF extraction could also serve as a technique for the recovery of antioxidants from spent coffee once the extract was furthermore purified and the lipid fraction removed.
This research paper investigates the use of 5-hydroxymethylfurfural (5-HMF) as marker for the heat treatment of spreadable dairy creams (
dulce de leche
, DL). The proposed method applies solid-phase ...extraction (SPE) with final analysis by liquid chromatography coupled with high-resolution mass spectrometry (SPE-LC–MS). The method was successfully applied to analyze spreadable dairy creams prepared by hot melt extrusion using different heating temperatures from 100 to 130 °C. The concentrations of 5-HMF correlated linearly with the applied temperatures, with a signal response in the range from 0.5 to 100 μM (
R
2
= 0.9997). The limit of detection (LOD) was 1.54 ± 0.03 µM with a precision of 1.77%. The results were compared with the analysis of 5-HMF in spreadable dairy creams using reference methods for the determination of 5-HMF in milk products. These methods mainly employed acid digestion and derivatization as pre-processing steps and determined 5-HMF spectrophotometrically and via HPLC–UV. These resulted in higher LOD (2.99 and 2.01 μΜ) and less precision (4.44 and 2.09%) compared to the proposed method. Furthermore, the proposed pre-processing procedure was faster by omitting the acid digestion and derivatization steps and by employing SPE.
This work has developed an optimized workflow for the targeted analysis of triacylglycerols (TAGs) in milk by liquid chromatography coupled with a Q-Exactive Orbitrap mass spectrometer. First, the ...effects of resolution (17,500; 35,000; 70,000; 140,000) and automatic gain control target (AGC, from 2×10
4
, 2×10
5
, 1×10
6
, and 3×10
6
) have been optimized with the goal to minimize the injection time, maximize the number of scans, and minimize the mass error. Then, the flow rate of the liquid chromatography system was also optimized by maximizing the number of theoretical plates. The resulting optimized parameters consisted of a flow rate of 200 μL/min, mass resolution of 35,000, and AGC target of 2×10
5
. Such optimal conditions were applied for targeted TAG analysis of milk fat extracts. Up to 14 target triglycerides in milk fat were identified performing a data-dependent HPLC-HRMS-MS2 experiment (t-SIM-ddMS
2
). The findings reported here can be helpful for MS-based lipidomic workflows and targeted milk lipid analysis.
Vitis vinifera L. ‘Gewürztraminer’ produces distinctive, aromatic wines that are strongly influenced by their terroir. This metabolomic study used a data-driven approach, including Principal ...Component Analysis (PCA) and Multifactorial Analysis (MFA), to correlate a quali-quantitative multivariate concept of terroir (including soil characteristics, and altitude) with sensory, phenolic, antioxidant, and volatile profiles of wines. The study analyzed wines from seven ‘Gewürztraminer’ vineyards, chosen to minimize the variability due to climate differences. Based on the soil data, the vineyards were clustered into two distinct groups: clay silicate (Group A) and dolomitic (Group B) soils. Group A exhibited lower levels of aromatic compounds such as linalool and higher levels of phenolic compounds such as gallocatechin than Group B. These findings indicate that even small changes in terroir within the same region can significantly impact the chemical, functional (antioxidant), and sensory properties of ‘Gewürztraminer’ wines, highlighting the importance of terroir in wine production. Statistical analyses confirmed the significance of these correlations (p < 0.05), highlighting the need for further research into the intricate relationship between terroir and wine quality.
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•Gewürztraminer vineyards in South Tyrol, Italy, were clustered based on geology.•The vineyards were found to form three groups, with one group an outlier.•Wines were analyzed using GC × GC-MS, LC-MS-CAD, and sensory analysis.•The wines from the vineyard groups were found to be distinctive.
Cardiovascular disease (CVD) can occur in COVID-19 and has impact on clinical course. Data on CVD prevalence in hospitalized COVID-19 patients and sequelae in survivors is limited. Aim of this ...prospective study carried out on consecutive unselected COVID-19 population, was to assess: 1) CVD occurrence among hospitalized COVID-19 patients, 2) persistence or new onset of CVD at one-month and one-year follow-up.
Over 30 days n = 152 COVID-19 patients underwent cardiovascular evaluation. Standard electrocardiogram (ECG), Troponin and echocardiography were integrated by further tests when indicated. Medical history, arterial blood gas, blood tests, chest computed tomography and treatment were recorded. CVD was defined as the occurrence of a new condition during the hospitalization for COVID-19. Survivors attended a one-month follow-up visit and a one-year telephone follow-up.
Forty-two patients (28%) experienced a wide spectrum of CVD with acute myocarditis being the most frequent. Death occurred in 32 patients (21%) and more frequently in patients who developed CVD (p = 0.032). After adjustment for confounders, CVD was independently associated with death occurrence. At one-month follow-up visit, 7 patients (9%) presented persistent or delayed CVD. At one-year telephone follow-up, 57 patients (48%) reported persistent symptoms.
Cardiovascular evaluation in COVID-19 patients is crucial since the occurrence of CVD in hospitalized COVID-19 patients is common (28%), requires specific treatment and increases the risk of in-hospital mortality. Persistence or delayed presentation of CVD at 1-month (9%) and persistent symptoms at 1-year follow-up (48%) suggest the need for monitoring COVID-19 survivors.
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•Cardiovascular involvement is common in hospitalized COVID-19 patients.•The occurrence of cardiovascular disease increases the risk of in-hospital mortality.•Cardiovascular evaluation in COVID-19 identifies patients who could benefit from specific treatment.•Short and long-term cardiovascular sequelae suggest the need for monitoring COVID-19 survivors.
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