Search

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.

Capsicum chinense Jacq., from the Yucatan peninsula, is recognized worldwide for its pungency, flavor, and secondary metabolites content. This has resulted in an increase in its production, which has led to an increase in the number of byproducts considered waste, mainly its leaves. Capsicum chinense leaves have been demonstrated to contain polyphenols with bioactive properties (antioxidant, anti-inflammatory, antiobesogenic capacity, etc.); hence, the extraction of polyphenols through the use of natural deep eutectic solvents (NADES) with a green technology, such as an ultrasonic probe, could help to revalue these leaves by maximizing the extraction efficiency and preserving their bioactive properties. The objective of this study was to optimize the composition of a eutectic solvent for obtaining an extract rich in polyphenols from the Capsicum chinense leaf using a sonic probe. The optimum conditions of the composition of NADES for obtaining the highest Antioxidant capacity (Ax, 79.71% inhibition) were a 0.8 mol glucose to 1 mol of choline chloride ratio, and 12% water. In addition, with this composition, the Total Polyphenol Content (TPC) obtained was 165.39 mg GAE/100 g dry leaf, and the individual polyphenols, such as vanillin (19.15 mg/100 g dry leaf) and ferulic acid (1.35 mg/100 g dry leaf), were optimized. The habanero pepper leaf extract obtained using a eutectic solvent and a sonic probe demonstrated a high potential for use as an ingredient in the development of nutraceuticals (i.e., functional foods).

In this study, vitamin A was encapsulated within oil-in-water emulsions by high-pressure microfluidization prepared using phosphate buffer (90%), corn oil (10%), and whey protein isolate (2%) as an emulsifier. The influence of microfluidization pressure (10, 50, 100, 200 MPa) on the particle size, zeta potential, and the physical and chemical stability of emulsions was evaluated. The physical stability of emulsion was determined by multiple light scattering technique. The content of vitamin A was measured by HPLC–DAD during an accelerated storage test at 40 °C during 4 weeks. The color of the samples was monitored using a colorimeter. The results showed that the lowest particle size distribution and the highest absolute value of zeta potential on the droplets’ surface charge were obtained by applying a pressure of 100 MPa. Nanoemulsions prepared at 100 MPa also showed the highest colloidal stability. However, higher microfluidization pressure (up to 200 MPa) had a negative impact on the prepared emulsion’s stability. The results of chemical stability by HPLC measurements during storage time were in agreement with the results of physical stability and color change.

This research aims to compare a novel cascade extraction method with a conventional solid–liquid extraction method, both assisted by ultrasounds. The cascade extraction method consists of a sequential series of extractions performed with the same hydroalcoholic solvent, which is reused from one herb to the other. In practice, a hydroalcoholic solution is firstly used to extract one botanical herb. The resulting extract is then reused for the extraction of a second herb. The process is repeated as many times as the number of herbs composing the final formulation. The main advantage of this approach is firstly the lower need of solvents compared with the individual extraction procedures, where a fresh solvent is needed on each extraction step. Furthermore, extracts of the two methods (solid liquid vs cascade extraction) were characterized with several antioxidant assays (DPPH, ORAC, and FRAP) and total phenolic content (TPC). The results show that the solid–liquid extraction method achieves similar yields to total phenols and similar TAC in comparison to the extracts obtained by the cascade extraction method. Also, the HPLC analysis of the extracts showed that both methods lead to similar chromatographic profiles either when analyzed by an electrochemical detector (CoulArray) or by a spectrometric diode array detector (DAD). However, our findings support the idea that the cascade extraction method obtains extracts richer of minor peaks, showing a more complex bioactive profile. Such results could be explained considering that the solvent used during the series of cascade extractions was enriched not only by antioxidants but also by plant surfactants, like saponins, which increase the solvent solubility. Overall, this research shows that the cascade extraction method can not only provide officinal herb extracts with similar phenolic yield and antioxidant capacity than conventional solid–liquid extraction but also with a more complex bioactive profile compared to traditional solid–liquid extraction and with a minor consumption of solvents.

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 2×104, 2×105, 1×106, and 3×106) 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 2×105. 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-ddMS2). The findings reported here can be helpful for MS-based lipidomic workflows and targeted milk lipid analysis.

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 (R2 = 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 investigates the effects of local environmental factors on the spiciness of Habanero chili peppers (Capsicum chinense Jacq.) by a coulometric electronic tongue. Chili fruits grown in red soil showed significantly higher spiciness (8.4 ± 1.9 mg g−1, expressed as mg of capsaicin per g of fresh fruit), than the one observed for fruits grown in brown (6.9 ± 2.5 mg g−1) and black (6.3 ± 1.7 mg g−1) soils. Moreover, the spiciness of the chili fruits increased when fruits ripened from green (6.4 ± 1.9 mg g−1) to orange (8.0 ± 2.2 mg g−1). In addition, subsequent harvesting cycles performed on the same plants stimulate the production of new fruits with higher spiciness level, especially on green fruits. Furthermore, this work will extend, from one side, the knowledge of coulometric electronic tongues as fast, comprehensive, and easy-to-handle alternative to estimate the taste of spicy foods in large-scale industrial experiments. On the other side, this work will also extend the knowledge on the effect of local environmental factors on the expression of capsaicinoids in Habanero chili.

Antimicrobial agents are substances that, when present at low concentrations, can delay microbial growth. For many years, several powerful antimicrobial substances have been synthetized. However, because of their significant side effects, there is a growing interest nowadays to find natural alternatives to the synthetic one. The present study aims to recover extracts with antimicrobial activity from Picea abies residues using two different extraction technologies, respectively, Soxhlet and supercritical carbon dioxide. Their antimicrobial activity was tested on the growth of Enterococcus faecalis and Streptococcus thermophilus. Isothermal calorimetry was used as a technique to quantify the antimicrobial effect of the extracts. The heat flow curves, obtained during the microbial growth, were fitted by a modified Gompertz function obtaining the lag time (λ) and the maximum growth rate (μmax) parameters. High-resolution mass spectrometry was used to identify the phenolic compounds responsible for the antimicrobial activity of the extracts. Regardless to the technology used, both extracts showed similar antimicrobial activity. For both microbial strains, the addition of the extract induced longer lag times (λ), while the maximum growth rate (μmax) decreased. S. thermophilus showed a higher resistance compared to E. faecalis suggesting a different capacity to metabolize the substrate in the presence of Picea abies extracts. Catechin, dihydroquercetin, astringin and isorhapontin were the identified phenolic compounds responsible for such effect. In conclusion, the results of this study provided an exciting potential for the future in light of the shift away from artificial preservatives and the trend toward natural alternative compounds coming from sustainable sources.

Background: The use of essential oils is receiving increasing attention worldwide, as these oils are good sources of several bioactive compounds. Nowadays essential oils are preferred over synthetic preservatives thanks to their antioxidant and antimicrobial properties. Several studies highlight the beneficial effect of essential oils extracted from medicinal plants to cure human diseases such as hypertension, diabetes, or obesity. However, to preserve their bioactivity, the use of appropriate extraction technologies is required. Method: The present review aims to describe the studies published so far on the essential oils focusing on their sources and chemical composition, the technologies used for their recovery and their application as antioxidants in food products. Results: The review has been structured in three parts. In the first part, the main compounds present in essential oils extracted from medicinal plants have been listed and described. In the second part, the most important technologies used for extraction and distillation, have been presented. In detail, conventional methods have been described and compared with innovative and green technologies. Finally, in the last part, the studies related to the application of essential oils as antioxidants in food products have been reviewed and the main findings discussed in detail. Conclusions: In summary, an overview of the aforementioned subjects is presented by discussing the results of the most recent published studies.

Dietary composition substantially determines human health and affects complex diseases, including obesity, inflammation and cancer. Thus, food supplements have been widely used to accommodate dietary composition to the needs of individuals. Among the promising supplements are dietary phospholipids (PLs) that are commonly found as natural food ingredients and as emulsifier additives. The aim of the present study was to evaluate the effect of major PLs found as food supplements on the morphology of intestinal epithelial cells upon short-term and long-term high-dose feeding in mice. In the present report, the effect of short-term and long-term high dietary PL content was studied in terms of intestinal health and leaky gut syndrome in male mice. We used transmission electron microscopy to evaluate endothelial morphology at the ultrastructural level. We found mitochondrial damage and lipid droplet accumulation in the intracristal space, which rendered mitochondria more sensitive to respiratory uncoupling as shown by a mitochondrial respiration assessment in the intestinal crypts. However, this mitochondrial damage was insufficient to induce intestinal permeability. We propose that high-dose PL treatment impairs mitochondrial morphology and acts through extensive membrane utilization via the mitochondria. The data suggest that PL supplementation should be used with precaution in individuals with mitochondrial disorders.

Nylon-6 nanofibrous membranes (NFM) prepared by electrospinning have been used as solid state support for the immobilization of the yeast Saccharomyces cerevisiae and then applied for the fermentation of grape juice. The membranes were characterized by scanning electron microscopy. The resulting metabolic activity was characterized by microcalorimetry. Sugar and ethanol changes during fermentation were monitored by HPLC. The results showed that the fermentation performance of immobilized yeasts on NFM is equal or even superior to the traditional fermentation process with yeasts freely dispersed in the medium. From calorimetry, free and immobilized yeasts showed the same enthalpy value in model solution, regardless to the amount of yeast loaded (52.2 ± 5.9 kJ mol−1 of glucose). Instead, immobilization of yeasts resulted in shorter lag time. Moreover, the maximum growth rate of immobilized yeasts was the same as with free yeasts in model solutions. However, the growth rate of immobilized yeasts was even higher, when performed in grape juice. In addition, the immobilization of yeasts on NFM exhibits the evident possibility of multiple reuse. Three consecutive fermentations were performed without significant loss of the overall performance. These findings support the development of nanostructured solid support for biocatalytic processes like fermentation of alcoholic beverages.

Isothermal microcalorimetry is often used to monitor microbiological activity and growth in various types of biological samples. Usually, it is useful to convert the isothermal microcalorimetry data into biologically meaningful data such as growth rate, lag phase or maximum growth. In this work, isothermal calorimetry was applied for monitoring of grape juice fermentation by Saccharomyces cerevisiae immobilized in nylon-6 nanofibrous membranes (NFM) prepared by electrospinning in comparison with freely dispersed yeasts. The resulting heat flow can be fitted using various approaches applying graphical, exponential, Gompertz, modified logistic and Michaelis–Menten models. Advantages and drawbacks of each approach for monitoring of the immobilized yeasts have been discussed in relation to the S. cerevisiae yeasts. Analysis of the fitting parameters showed that immobilized yeasts had the highest growth rate and maximum growth in comparison with freely dispersed yeasts. Parallel measurements of sugar and oxygen consumption rates for immobilized and free yeasts cells confirmed the calorimetric data. The results of this work demonstrate practical approach to analysis and modeling of calorimetric data in food analysis and advantages of application of NFM as solid support for yeast immobilization.

This study investigates the effect of harvesting altitude, fermentation time and roasting degree on the volatile profile released by coffee (Coffea arabica, variety Catimor) powder. The analysis of the volatile organic compounds was performed by proton transfer reaction mass spectrometer (PTR-MS). The experimental design consisted of three factors: altitude at two levels (900 m and 1500 m, milder and harsher climate, respectively), four different fermentation times (0, 24, 48 and 72 h) and roasting at three levels (light, medium and dark). Analysis of the released volatile organic compounds (VOCs) revealed that the intensity of m/z 45 and 59 dramatically decreases at a higher harvesting altitude. Longer fermentation times induce a decrease of m/z 61 and 75, probably related to the activity of the isocitrate lyase. Finally, a prolonged roasting degree induces a rise of the m/z 61, 75, 81 and 97. The total count per second measured by PTR-MS was used as an index of “overall coffee aroma intensity” to build a linear regression model. The model was used to predict the total VOCs intensity on the basis of the altitude, fermentation time and roasting level. The validation of the model (adjusted R2 = 0.91 and normalized relative standard deviation in prediction of 7%) reveals that, although the degree of roasting clearly affects the resulting aroma intensity, altitude and fermentation time also play a role in the formation of the volatile profile. Moreover, a significant interaction was observed between the altitude where the bean were grown and the roasting level. These results support the hypothesis that the type of process of the seeds has a strong impact on the resulting coffee’s quality. Furthermore, PTR-MS coupled with linear regression models is a powerful tool for the quality control of coffee process.

Extrusion cooking is receiving increasing attention as technology applied for the production of protein-based products. Researchers in this field showed that proteins from several sources are barely consumed because of their poor functionality and lack of acceptability related to the presence of some antinutritional factors. In this regard, extrusion is becoming of key importance thanks to its ability to improve protein functional properties. Based on this remarkable advantage, several studies have been published so far providing evidence of the enhanced functional, physicochemical and sensory properties of protein-based extruded products. The objective of the present review is to give a detailed overview of the potential of extrusion for the production of protein-based products. More specifically, the work describes all the studies published so far on vegetable and animal proteins including those recently released applying the technology on insect proteins. The aspects related to the functional properties of the extrudates together with the quality changes occurring during the process are also described to highlight the potential of the technology for future applications.

Non-extractable polyphenols (NEPs), or bound polyphenols, are a significant fraction of polyphenols that are retained in the extraction residues after conventional aqueous organic solvent extraction. They include both high molecular weight polymeric polyphenols and low molecular weight phenolics attached to macromolecules. Current knowledge proved that these bioactive compounds possess high antioxidant, antidiabetic, and other biological activities. Plant-based food by-products, such as peels, pomace, and seeds, possess high amount of NEPs. The recovery of these valuable compounds is considered an effective way to recycle food by-products and mitigate pollution, bad manufacturing practice, and economic loss caused by the residues management. The current challenge to valorise NEPs from plant-based by-products is to increase the extraction efficiency with proper techniques, choose appropriate characterising methods, and explore potential functions to use in some products. Based on this scenario, the present review aims to summarise the extraction procedure and technologies applied to recover NEPs from plant-based by-products. Furthermore, it also describes the main techniques used for the characterisation of NEPs and outlines their potential food, pharmaceutical, nutraceutical, and cosmetic applications.

The quadrupedal locomotion of bats still remains almost unexplored. Meanwhile, in the life of many species, this type of movement plays an important role. This paper presents the study of characteristics of quadrupedal locomotion on vertical surfaces in bats. We provide the results of the analysis of climbing of five vespertilionid species. The study is based on high-speed video recording of locomotion in two planes in an experimental enclosure on various substrates (the bark of five tree species and the inner surface of the manufactured nest box for bats). For comparison, we used data on horizontal locomotion obtained using the same experimental facilities, as well as all available literature data to date. The time, metric and velocity characteristics of the movement of different species representatives are determined. We show how these characteristics are interrelated and how they differ in walking or climbing. The study comparing walking vs. climbing was performed for the second time ever. It is shown that while climbing, bats retain the same limb sequence, but the gait is not a slow trot-like walk but a very slow walk. There are considerably fewer deviations from the usual symmetrical sequence gait (wherein a forelimb movement is followed by that of the contralateral hind limb) when climbing than when walking, and they are all associated with the search for support. Our results show that not all tree-dwelling species of vesper bats can move up the trees which they use to roost. The surface of the inner walls of artificial shelters for bats may be a significant factor in their occupancy. While designing such shelters, it is advisable to consider the results of our experiments or conduct tests on the behavior of particular species on specific artificial surfaces.

Method for the determination of Scoville index of pepper pungency using flow injection analysis with an amperometric dual electrode detection on thin-layer glassy carbon electrode is described, with applied combination of electrode potentials +1.0 V and 0.0 V. The sample is prepared by 15 min extraction of 0.2 g of dried powdered peppers of pepper by 10 mL of acetonitrile, followed by 15 times dilution by carrier solution, i.e. acetonitrile: acetate buffer pH 4 (95:5, v/v). The dual electrode detection offers accurate results for pepper samples of medium to high pungency. The suggested method can therefore offer efficient tool for the routine pepper pungency determination.

This work explored the potential of supercritical fluid extraction (SFE) to recover phenolic compounds and antioxidants from apple pomace. SFE was carried out at 20 and 30 MPa and temperature of 45 and 55 °C in absence and presence of ethanol (5%) as co-solvent. The results were then compared to those obtained by Soxhlet extraction with ethanol and boiling water maceration. All the extraction techniques were performed on fresh, oven and freeze dried samples. The extracts were characterized for their antioxidants capacity with different assays, such as the Folin-Ciocalteu, the 2,2-diphenyl-1-picryhydrazyl radical (DPPH) and a flow injection coulometry technique. The results showed that the extracts obtained from SFE, carried out on freeze dried apple pomace at 30 MPa and 45 °C for 2 h with ethanol (5%) as co-solvent, led to a higher antioxidant activity (5.63 ± 0.10 mg TEA/g of extract) than conventional extraction technologies such as Soxhlet with ethanol (2.05 ± 0.21 mg TEA/g of extract) and boiling water maceration (1.14 ± 0.01 mg TEA/g of extract). The HPLC-DAD-MS analysis also confirmed the abundance of some phenolic compounds in SFE extract. Overall, the study presented here is one of the first investigations to assess the impact of supercritical carbon dioxide for the extraction of antioxidants from apple pomace.

Freshly harvested Tuber melanosporum samples were packed and stored at 4°C under reduced atmospheric pressure or modified atmosphere for four weeks. Multivariate analysis was employed to correlate the antioxidant power of the ethanolic extracts of the samples with the chemical composition determined by high resolution mass spectrometry. High performance liquid chromatography coupled with a coularray detector was applied to select the chemical species associated with the antioxidant power. Four classes of chemical compounds were investigated in more detail by a targeted approach: derivatives of glutathione, adenine (such as S-adenosyl-homocysteine), oxidized linoleic acid and ergosterol. Adducts containing glutathione and adenine with oxidized linoleic acid were observed in TM for the first time and can be considered markers of freshness of the product. S-adenosyl-homocysteine, the acetyl-carnitine adduct with cysteinyl-glycine and several oxidized linoleic acid derivatives were among the markers of degradation.

This work determines the radical scavenging activity of antioxidants and berry extracts based on the heat generated during their reaction with hydrogen peroxide, under isothermal condition (25 °C). After addition of H2O2 to a water solution containing antioxidants, an exothermic heat flow appeared. After an initial damping time, the signal decayed exponentially, following a first-order kinetic. Through an iterative fitting routine, both thermodynamic (ΔH) and kinetic (k) information were achieved. Such approach was applied toward relevant food antioxidants, revealing that the fastest reactivity (k) was for tannic acid > gallic acid > caffeic acid > ascorbic acid. Interestingly, k was inversely correlated with ΔH (r = −0.96) and with the DPPH test (r = −0.98). Apparently, strong radical scavengers show faster kinetics and lower ΔH-values, as expected, respectively, from a high reactivity toward peroxyl radical and efficient delocalization capacity. Such approach was finally applied to berry extracts (mixed grape seed and skin; chokeberries; grape seed; goji berries). The resulting ΔH-values were correlated with three indices, namely, total phenol, amperometry, and DPPH test. However, k-values largely deviated from these indices. Such discrepancy was explained considering that none of these indices is a “true” measure of the kinetic of the reaction, but only express an apparent concentration. Conversely, reaction calorimetry provides directly and simultaneously both thermodynamic and kinetic properties of the radical scavenging reactivity of antioxidants or natural extracts.