European Food Research and Technology

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Agarose gel electrophoresis of DNAs extracted from plant materials by Doyle and Doyle (1987) (leaves (a), raw (b) and roasted (c) kernel, raw (d) and roasted (e) episperm) and food matrices by Doyle and Doyle (homemade (f) and industrial (g) paste, grain (h), flour (i)) and by Nucleospin® Kit (cookies (j), cream (k) and chocolate (l))
SSR profile of cultivar ‘Tonda Gentile’ used as a reference to estimate the correspondence of DNA obtained from different matrices. The electropherogram was obtained using 3130 Genetic Analyzer and shows the alleles and their size (bp) at 5 SSR loci (CaT-B501, CaT-B502, CaT-B504, CaT-B107, CaC-B028)
SSR profiles of DNA extracted from raw (a) and roasted episperm at 110 °C (b). The electropherogram was obtained using 3130 Genetic Analyzer and shows the alleles and their size (bp) at 5 SSR loci (CaT-B501, CaT-B502, CaT-B504, CaT-B107, CaC-B028). There is complete identity with the reference profile of cultivar ‘Tonda Gentile’
SSR profiles of DNA extracted by Nucleospin® Food kit from homemade paste (a) and industrial paste (b), upper part of the figure. The electropherograms were obtained using 3130 Genetic Analyzer and show the alleles at 5 SSR loci (CaT-B501, CaT-B502, CaT-B504, CaT-B107, CaC-B028). The alleles of the cultivar ‘Tonda Gentile’ (bottom of the figure) are visible in the pastes at all loci as dominant peaks. Moreover, additional alleles are evident, owing to the presence of the pollenizers’ DNA
SSR profiles of DNA extracted by Nucleospin® Food kit from cookies (a, left) and chocolate (b, right). The electropherograms were obtained using 3130 Genetic Analyzer and show the alleles at 5 SSR loci (CaT-B501, CaT-B502, CaT-B504, CaT-B107, CaC-B028). It is possible to observe the presence of many alleles, owing to the presence of the pollenizers’ DNA, in addition to the mother cultivar’s alleles
Article
The request for an efficient traceability system able to identify hazelnut cultivars along the entire processing chain is becoming a critical point for avoiding fraudulent practices and safeguarding the interests of growers, food processors and consumers. In this study, DNA was extracted from different hazelnut matrices, including plant material (leaf, kernel and kernel episperm), and processed foods (paste, grain, flour and different types of snacks containing hazelnuts). The efficiency of Simple Sequence Repeat (SSR) markers was tested to identify the hazelnut cultivar ‘Tonda Gentile’ in all the supply chain. The analysis at 10 SSR loci was able to verify the presence/absence of the alleles of a declared cultivar contained in these matrices. The SSR analysis of DNA from raw episperm offers the possibility of identifying the mother cultivar and is suggested as an effective way to discover frauds since DNA analysis can be performed on individual kernels. For food matrices containing hazelnuts, the presence of the mother cultivar’s DNA can be assessed based on the identification of its alleles in the sample, although the presence of multiple alleles from the pollenizers makes the interpretation of results more difficult.
 
Cryo-SEM image of a cross section revealing the different cells and structures in a convectively roasted cocoa bean at 160 °C for 30 min, defatted with hexane
Cryo-SEM images (x250) of cross sections of different conditions of convectively (left) or microwave- (right) roasted cocoa beans defatted with hexane
PCA biplot of 64 aromatic compounds plotted together with the factor loadings of liquors produced from convection- (filled circle) and microwave- (filled triangle) roasted cocoa beans under different conditions (n = 3). Conditions: convectively roasted (110 °C–30 min, 130° C–10 min, 130 °C–30 min, 130 °C–50 min, 160 °C–30 min), microwave roasted (180 W–12 min, 300 W–7 min, 300 W–12 min, 300 W–17 min, 450 W–12 min). Aromatic molecules (x): 1–7,OA = organic acids; 8–14,ALC = alcohols; 15–27,PY = pyrazines; 28–33,ALD = aldehydes; 34–37,TE = terpenes; 38–43,KE = ketones; 44–55,FPP = furan and pyran derivates and pyrroles; 56–63,ES = esters; 64,NI = nitrile
Two-dimensional self-organizing map (SOM) visualizing the clustering of liquors produced from convectively and microwave-roasted cocoa beans (n = 3) under different conditions
Article
Microwave roasting of cocoa beans was studied as an alternative toward convection roasting. The impact of each roasting treatment was assessed based on roasting degree indicators (moisture content, color, tetramethylpyrazine/trimethylpyrazine ratio), microstructural changes as visualized by cryogenic scanning electronic microscopy (cryo-SEM) and the aroma development as determined by head space-solid phase microextraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS). Time (10–50 min) and temperature (110–160 °C) were varied for convection roasting, whereas time (7–17 min) and power input (180–450 W) were altered for microwave roasting of cocoa beans. Results revealed that by selecting appropriate microwave-roasting parameters (time and power input), cocoa beans with a more pronounced brown color and lower tetramethylpyrazine/trimethylpyrazine ratio could be obtained, while having a similar moisture content compared to convection roasting. At microstructural level, differences in number and size of macropores were not directly related to the roasting technique, but were principally determined by the applied temperature or power input. Based on the aroma profile, microwave roasting resulted in a more intense cocoa aroma, compared to convection roasting. Therefore, microwave roasting could be a promising alternative technique to roast cocoa beans in a shorter processing time while creating a more intense aroma.
 
Article
Astragali Radix (AR) is commonly used as the herbal drug in the traditional Chinese medicine. In this study, cultivated AR (AR-C) and wild/semi-wild AR (AR-W) were compared by ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). With the help of multiple mass defect filter (MMDF) and the Global Natural Products Social Molecular Networking (GNPS), chemical investigation of the AR led to the tentative annotation of 196 compounds, including 76 isoflavones and flavones, 50 isoflavanes and pterostanes, 44 saponins, and 26 other compounds. Further analysis showed that 55 compounds (17 isoflavones and flavones, 25 isoflavanes and pterostanes, 8 saponins, and 5 others) showed higher contents in the AR-W. There were 13 compounds showed FC values higher than 3, and further ROC analysis showed 1 of them could be used as the marker for discrimination of AR-C and AR-W. We also found that isoflavanes, pterostanes, and isoflavones were more likely to be substituted by malonyl groups than the flavones and astragalosides, and the sum of malonyl-substituted flavonoid glycosides and corresponding precursor were also higher in AR-W than AR-C. However, the correlation between the chemical difference and the pharmacological difference is needed in the future studies.
 
Article
Quality parameters and bioactive compounds of two white garlic samples from two regions of Turkey (Gaziantep and Kastamonu) and five commercial black garlic samples were investigated. It was found that the black garlic samples had greater total sugar content. Black garlic samples had also higher total amino acids (112.9–684.8 mg/100 g) as compared to the white garlics (250.8–411.9 mg/100 g). Arginine and glutamic acid were the dominant amino acids in both product types. Cysteine, the key amino acid responsible for the principal health-promoting properties of garlics, was found to be much higher in black garlic samples (112.0 µg/100 g in BG4) when compared to white garlic samples (21.4 µg/100 g in KWG). Black garlic samples had 4–7 times more antioxidant potential as compared to the white garlics. It was also found that the predominant sugar compound was sucrose (702.3–884.7 mg/100 g) in white garlic and fructose (3277.0–27,232.2 mg/100 g) in black garlic samples and the total amount of sugar was 4- to 17-fold higher in black garlic compared to the white garlic. 13 and 14 phenolic compounds were quantified by LC-DAD-ESI-MS/MS in the white and black garlic samples, respectively. Black garlic was found to have a higher phenolic content (26.3–37.9 mg/100 g) than white garlic (18.0–23.3 mg/100 g) while caffeic acid was the dominant phenolic in both product types. In general, black garlic could be recommended to consumers due to its higher potential of bioactive compounds.
 
Discriminant analysis based on terpenoid contents of grape mash samples (n = 60) grouped according to aroma type
Combined score plots of the first two principal components of grape mash samples (n = 200) analysed for aroma compounds with (filled triangles) and without (filled circles) addition of artificial saliva solution. The loadings of selected aroma compounds are included in the score plot
NIR spectrum of a grape mash sample from the variety Acolon (averaged from 300 spectra)
Article
The production of high-quality wines requires the use of high-quality grapes. Tasting represents a widespread method for the determination of grape maturity and quality aspects such as the corresponding aroma profile. However, sensory analysis always remains subjective and it is not possible to judge only aroma compounds because the overall impression is also influenced by main components (e.g. sugars and acids). In contrast, the use of near-infrared (NIR) spectroscopy allows the simultaneous determination of various compounds without being affected by personal preferences. In this study, grape mash samples were examined under comparable conditions to those in the mouth. Differences between grape mashes with varying phytosanitary status of the corresponding grapes as well as for different grape varieties were detected. The quantified concentrations of the detected aroma compounds were used to develop calibration models for determination by NIR spectroscopy. Using global calibration models, the single aroma compounds could be determined by NIR spectroscopy with accuracies reaching from R ² C = 0.365 to R ² C = 0.976. Separate calibration models for cultivation region and grape colour improved the prediction accuracy. Instrumental analysis cannot totally replace sensory evaluation, however, NIR spectroscopy has the potential to be used as an objective, additional method for the evaluation of grape aroma quality.
 
The general block diagram of the evaluation of the effect of lacto-fermentation on changes in the carrot using image analysis and machine learning
The color images of lacto-fermented (a) and fresh (b) carrot slices
The lacto-fermented and fresh carrot slice images from randomly chosen color channels
Article
This study was aimed at evaluating the effect of spontaneous lacto-fermentation of carrot slices on flesh structure using different machine learning approaches. The textures computed from digital images of lacto-fermented and fresh carrot slices were compared using neural networks and other algorithms from different groups. In the case of Multilayer Perceptron, accuracies for training, testing and validation were considered. For some of the networks, lacto-fermented and fresh samples were completely distinguished. The accuracies for training, testing and validation were equal to 100%. For models built using other algorithms (LDA (Linear Discriminant Analysis), Multi Class Classifier, LMT (Logistic Model Tree), KStar, Naive Bayes, PART), the following metrics were used for the evaluation of model effectiveness: accuracies, time taken to build model, Kappa statistic, mean absolute error, root mean squared error, PRC (Precision-Recall) Area, ROC (Receiver Operating Characteristic) Area, MCC (Matthews Correlation Coefficient), F-Measure, Recall, Precision, FP (False Positive) Rate and TP (True Positive) Rate. The most satisfactory results were obtained for the LDA. The lacto-fermented and fresh carrot slices were distinguished with an average accuracy of 99%, low values of errors (mean absolute error: 0.0117, root mean squared error: 0.1014) and FP Rate (0.010). The weighted averages of other metrics were greater than or equal to 0.98 (Kappa statistic: 0.98, PRC Area: 0.987, ROC Area: 0.991, MCC: 0.980, F-Measure: 0.990, Recall: 0.990, Precision: 0.990, TP Rate: 0.990). The obtained results demonstrated the usefulness of different machine learning approaches to the evaluation of the effect of fermentation on changes in the carrot flesh structure.
 
Specific mechanical energy during extrusion of seedless blackcurrant pomace at different temperature and varying moisture content. Lowercase letters indicate significant differences (p < 0.05) caused by pomace moisture; uppercase letters indicate significant differences caused by extrusion temperature (p < 0.05); the interaction of the parameters moisture and temperature was insignificant
Colour coordinates of seedless blackcurrant pomace (SBC) as affected by extrusion conditions (encoded with temperature [°C]/pomace moisture [g/100 g]) or planetary ball milling for 2 h (PM2) or 4 h (PM4). Lightness L* is proportional to circle area as indicated
Techno-functional properties of seedless blackcurrant pomace (SBC) after extrusion at different temperature with varying moisture content (left) and after planetary ball milling (right). Horizontal planes in the left graphs indicate the level of the initial SBC. Lowercase letters indicate significant differences (p < 0.05) caused by pomace moisture; uppercase letters indicate significant differences caused extrusion temperature (p < 0.05); the interaction of the parameters moisture and temperature was insignificant. Different superscripts in the right graphs indicate significant differences (p < 0.05) between milling times
Sugar content of dried aqueous extracts of seedless blackcurrant pomace (SBC) after extrusion at different temperature with varying moisture content (left) and after planetary ball milling (right). Horizontal planes in the left graphs indicate the level of the initial SBC. Lowercase letters indicate significant differences (p < 0.05) caused by pomace moisture; uppercase letters indicate significant differences caused by extrusion temperature (p < 0.05); the interaction of the parameters moisture and temperature was insignificant. Different superscripts in the right graphs indicate significant differences (p < 0.05) between milling times
Article
Exploring the use of seedless blackcurrant pomace, a fibre-rich by-product of juice pressing, in foods is favourable due to its nutritional profile but also for economic and sustainability aspects. Current applications are limited to products in which rapid fibre swelling, high water solubility or low sedimentation is not essential. In this study, functional properties of seedless blackcurrant pomace were modified by thermo-mechanical treatments using extrusion cooking or micronization in a planetary ball mill. A full factorial design showed that low pomace moisture (11 g/100 g) had the highest impact on swelling capacity (+ 20.6%) and water solubility index (+ 23.2%), whereas variation in extrusion temperature exhibited only minor effects. After milling for 4 h, the median particle size was reduced by 98% to 4 µm and the specific surface area increased from 0.1 to 2.5 m ² /mL. Swelling capacity was highest after this time with 7.6 mL/g pomace and, although the amount of extractable sugars was reduced, water solubility increased to 7.6 g/100 g. In contrast to extruded samples, the red colour of the pomace was intensified after milling. Both treatments appear as promising to extend the applicability of fruit by-products in foods, as micronized pomace may counteract sedimentation in liquids, whereas increased swelling capacity after extrusion may have stabilizing effects on yoghurt-like systems.
 
Treatment application in two ripening stages of Monastrell grapes
Concentration of mannoproteins (MPs) (A), polysaccharides rich in arabinose and galactose (PRAGs) (B) and rhamnogalacturonans type II (RG-II) (C) in wines from Monastrell grapes. Different letters indicate significant differences according to a Duncan test (p < 0.05)
Concentration of total polysaccharides (A) and oligosaccharides (B) in wines from Monastrell grapes. Different letters indicate significant differences according to a Duncan test (p < 0.05)
Article
The application of elicitors, such as methyl jasmonate (MeJ) and benzothiadiazole (BTH), has provided satisfactory results by increasing the polyphenol content of grapevines. However, in the case of some treated grape varieties, it is difficult to extract their phenolic compounds into the wine, because of variations in the components of the skin cell wall (SCW) and the potential effects on some complex carbohydrates (polysaccharides and oligosaccharides). This paper attempts to ascertain whether the individual application of MeJ and BTH at two points of the maturation cycle (veraison and mid-ripening) of Monastrell grapes, influences the content of complex carbohydrates released into wines. The application of elicitors in the vineyard did not affect the concentration of mannoproteins (MPs) (from yeast) in the resulting wine. However, MeJ, BTH and MeJ + BTH treatments (at veraison or mid-ripening) reduced the concentrations of ramnogalacturonans type II (RG-II) and total polysaccharides (TPs) (both from grapes) released into the wine. Results suggest that a reduction of pectic derivatives and/or a reinforcement of SCW occurred as a result of the action of these elicitors, decreasing the release of polysaccharides and oligosaccharides into the wine during maceration. However, sensory analysis found that tasters were not able to distinguish between wines from control and treated grapes. Further years of study are needed, in this and other varieties and locations, to determine the extent of possible cell wall modifications associated with elicitor treatments.
 
Article
The most common preservation process for chili peppers is drying, which inevitably causes oxidative degradation of thermolabile molecules. The aim of this research was to evaluate the potential protective effect exerted by an active ingredient based on grape seed oil, on pepper fruits. Grapeseed oil is rich in antioxidant compounds and was applied to pepper’s surface in form of a sol–gel product, before fruit thermal treatment. In this work, chili peppers samples were preventively treated with an active solution, and controls (untreated peppers), were submitted to a drying process performed at two different temperatures: 45 and 65 °C. Analysis of capsaicinoids, carotenoids, apocarotenoids, and phenolic content was performed to evaluate possible differences between the sets of samples. Oxidative stability of oil enriched with chili pepper powder aliquots was also measured to evaluate the antioxidant power of the samples. Obtained data showed that treated samples retained a higher amount of capsaicinoids and carotenoids. Oxidative stability of pepper powder was also higher for treated samples than for controls. Furthermore, the thermal treatment performed at 45 °C caused milder modifications than the 65 °C treatment. The applied pre-drying treatment can be proposed to prevent bioactive compounds loss and to enhance product stability and shelf-life.
 
a, c and e Relative peak areas of skatole (SK) and androstenone (AEON) in % determined by HS-SPME–GC–MS in HS vials after 7 days of culture with 27 basidiomycetous strains in three successive experiments. b, d and f Perceived odor intensities of SK and AEON on agar plates after 7 days of culture by the trained panel in three successive experiments. The intensities of the odor substances were described on a 0–10 scale (0 = not perceptible, 10 = very intensely perceptible), and the controls without fungus were also analyzed on day 7 and had an intensity of 10. The total number of observations was n = 15 (5 panelists × 1 replicate in three sessions). The error bars indicate the standard deviation of all observations. In Fig a, c, and e, all the treatments showed significant differences with control for SK; the asterisk indicates significant differences with the control for AEON (p < 0.05). b, d and f The asterisk indicates significant differences with the control (p < 0.05)
Relative peak areas of skatole (SK) and androstenone (AEON) in % determined by SPME–GC–MS in HS vials after bioconversion overnight with enzyme fractions prepared from four selected strains: extracellular enzyme fraction (EEF), intracellular enzyme fraction (IEF), and mycelial enzyme fraction (MEF). Buffer inoculated with SK/AEON mixture was used as control (blank). The error bars indicate standard deviations of the measurements (n = 3). Treatment with enzyme fractions from all strains showed significant differences with controls (SK/AEON) using a Duncan’s test (p < 0.05), except for SK treated with IEF from ILA, Fig. 2c (#; p > 0.05). Different letters mean significant differences between active and deactivated samples (p < 0.05)
Aggregated results of 2-AFC tests for bioconversions with extracellular enzyme fraction (EEF) in active and deactivated form vs. control regarding the odor perception of AEON, SK, and a mixture of AEON/SK (Boar Taint). The Y-axis shows the relative frequencies of which sample was chosen to be more intense in odorant perception. The total number of observations was n = 35 (7 panelists × 5 replicates divided in two sessions) for AEON and SK and n = 30 for AEON/SK (boar taint) (6 panelists × 5 replicates in two sessions). Cont = Control
Aggregated results of 2-AFC tests for bioconversions with enzyme fraction mycelial enzyme fraction (MEF) in active and deactivated form vs. control regarding the odor perception of AEON, SK and mixture of AEON/SK (Boar Taint). Y-axis shows relative frequencies of which sample was chosen to be more intense in odorant perception. Total number of observations was 30 (5 panelists × 6 replicates divided in two sessions) for all samples AEON, SK and AEON/SK (boar taint). Cont = Control
Article
Wood-degrading fungi and enzyme preparations derived thereof were identified to degrade boar taint compounds. Fungal strains (n = 27) were analytically and sensorially screened for skatole (SK) and androstenone (AEON) degradation in head space (HS) vials and agar plates, respectively. Eight strains were able to reduce > 80% of AEON and > 80% of SK intensities. Three enzyme fractions (extracellular, intracellular, and mycelial) obtained from submerged cultures of Cerrena zonata, Irpex lacteus, Marasmius cohortalis (MCO), and Trametes hirsuta were used for SK and AEON bioconversion. Several enzyme fractions were able to reduce 90–100% of SK/AEON concentrations in the reaction mixtures based on the volatile analysis. MCO extracellular enzyme fractions (EEF) and mycelial enzyme fractions (MEF) were able to completely abolish both compounds and were therefore used for a sensory 2-alternative forced choice discrimination test in parallel to quantitative analysis. HS-SPME–GC–MS results demonstrated that active EEF and active MEF reduced > 98% SK and AEON intensities individually and > 92% in the SK/AEON mixture. Discrimination tests with trained panelists revealed that samples were perceived significantly less intense regarding SK, AEON, and SK/AEON than the control samples with d’ values (a discrimination value) of 1.19, 0.74, and 0.72 for active EEF and 2.12, 0.88, and 2.12 for active MEF respectively, which were well in line with the analytical results. This indicates that both fractions (EEF and MEF) were effective in the boar taint reduction in aqueous solutions. The study revealed that Basidiomycota or enzymes derived thereof may become interesting tools to remove boar taint compounds.
 
Article
Taste is a sensory modality crucial for nutrition and survival, since it allows the discrimination between healthy foods and toxic substances thanks to five tastes, i.e., sweet, bitter, umami, salty, and sour, associated with distinct nutritional or physiological needs. Today, taste prediction plays a key role in several fields, e.g., medical, industrial, or pharmaceutical, but the complexity of the taste perception process, its multidisciplinary nature, and the high number of potentially relevant players and features at the basis of the taste sensation make taste prediction a very complex task. In this context, the emerging capabilities of machine learning have provided fruitful insights in this field of research, allowing to consider and integrate a very large number of variables and identifying hidden correlations underlying the perception of a particular taste. This review aims at summarizing the latest advances in taste prediction, analyzing available food-related databases and taste prediction tools developed in recent years. Supplementary information: The online version contains supplementary material available at 10.1007/s00217-022-04044-5.
 
Article
The rumen of ruminants contains a variety of fungi with function of producing xylanases to break down plant cell walls. In this study, a new glycoside hydrolase family 10 (GH10) xylanase gene ArXyn10c20 from anaerobic rumen microorganism Anaeromyces robustus was successfully synthesized and expressed in Pichia pastoris GS115, with a protein molecular weight of approximately 42 kDa. The optimum pH and temperature for ArXyn10c20 were 5.5 and 40 ℃. ArXyn10c20 was stable in the pH range 5.0–9.0, retaining over 75.0% relative activity for 1 h. The activity of recombinant xylanase was significantly enhanced by 1 mM Cu²⁺. The products of ArXyn10c20 hydrolysis of beechwood xylan were xylobiose, xylotriose and xylotetraose by thin-layer chromatography analysis. In food applications, ArXyn10c20 can significantly improve the quality of dough and bread. With the addition of 420 U of ArXyn10c20 per 100 g flour, the hardness, gumminess and chewiness of the bread decreased by 42.2%, 45.3%, and 55.4%, respectively, and the reducing sugar increased by 18.7%. The new discovered xylanase ArXyn10c20 has great potential in food industry.
 
2D Scatterplots for the 18 anchovy samples categorized by different cooking methods. Insert: loading plot for PC1 and PC2
Article
Fish is healthy part of the human diet due to the high content of long chain n-3 polyunsaturated fatty acids (n-3 PUFA) as eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3). Different cooking techniques have a significant influence on the fatty acid profile of bluefish. In this work, the fatty acid profile in Mediterranean anchovies (Engraulis encrasicolus) was evaluated in cooked and uncooked fish. From the fatty acid profile, the atherogenicity (AI) and thrombogenicity (TI) indices were calculated. The results showed that roasting and frying had significant differences on fatty acid composition. Marinating showed only little effect on fatty acid content, while steaming and boiling are the cooking methods that most preserved the overall fatty acid content. The frying method, in specific, appears not to be recommended to preserve the omega-3 fatty acid composition of anchovies: EPA and DHA of 85% and 66% of the initial value, respectively. Verily, considering the lipid content of samples, the amount of EPA + DHA it is not subject to a substantial decrease. Frying has certainly increased the content of n-6 polyunsaturated fatty acids and monounsaturated fatty acids, as result of the cooking oil used (olive). Therefore, in all cooking methods, the omega-3 fatty acids were well preserved. Consequently, the nutritional quality related to fatty acids profile of fried anchovies is equivalent than that of anchovies prepared following other cooking methods. The olive oil, however, leads in good quality fried product in relation to the values of the atherogenicity and thrombogenicity indices.
 
Flow diagram of strawberry spread preparation. Numbers 1–5 indicate the addition sequence
UHPLC-DAD chromatograms at 280 and 365 nm of Rosa damascena Mill. petals. For peak assignment see Table 1
Contents of total polyphenols (TPP, mg GAE/100 g) and total monomeric anthocyanins (TMA, mg CGE/100 g) of plain and polyphenol-enriched (PE, addition of rose petal extract) strawberry spreads
Lightness (L) chroma (C) and hue angle (h) values of plain and polyphenol-enriched (PE, addition of rose petal extract) strawberry spreads
Article
A new process for enzyme-assisted extraction of polyphenols from de-aromatized rose (Rosa damascena Mill.) petals, primary by-product of essential oil production, was developed. Among the 19 major compounds analysed by liquid chromatography–mass spectrometry, 5 hydrolyzable tannins and 14 flavonols were detected in the rose petal extract. To the best of our knowledge, the presence of galloylquinic acid and ellagitannins has not been described before in Rosa damascena. The enzymatic processing led to 1.5–1.8 times higher contents of individual flavonols as compared to the control (without enzymatic treatment) sample. The co-pigmentation efficiency of enzymatically extracted rose petal polyphenols was evaluated regarding color stabilization in strawberry processing. The results obtained demonstrate that the addition (0.5%, w/w) of rose petal extract enhances the color intensity of strawberry spread, thus meeting the growing consumer demand for substitution of synthetic food additives by natural alternatives.
 
Comparison of aroma profiles between original black tea infusions and the aroma recombination models by sensory panel
Comparison of aroma profiles between original black tea infusions and the aroma recombination models by electronic nose
Article
The volatile compounds of three world-famous black teas (Darjeeling, DJL, Keemun, KM, and Ceylon, CL) were extracted by stir bar sorptive extraction (SBSE), and analyzed by gas chromatography–olfactometry (GC–O), gas chromatography–mass spectrometry (GC–MS). The results indicated that 78, 76, and 69 volatile compounds were detected in the three tea infusions. And 9 sulfur compounds in black teas were identified by gas chromatography–flame photometric detection (GC–FPD). In addition, a total of 42 aroma compounds were perceived and 38 compounds were identified as important aroma compounds due to their high odor activity values (OAVs), such as 3-methylbutanal (OAV: 24–82), linalool (OAV: 24–64), geraniol (OAV: 2–97), β-ionone (OAV: 54–122), and cis-jasmone (OAV: 2–119). According to the results of aroma recombination and omission experiments, 2-methylbutanal, linalool, methyl salicylate and β-cyclocitral were confirmed to be the key aroma compounds in Darjeeling black tea, 3-methylbutanal, hexanal, β-myrcene, and methyl salicylate were the key aroma compounds in Keemun, while β-ionone, linalool, 2-methylbutanal, and salicylaldehyde were the key aroma compounds in Ceylon black tea.
 
Article
This paper discusses the signal quality of differential scanning calorimetry (DSC) measurements performed on high-protein materials, and takes grinded peanuts as an example. Four different samples were used, including three grades of roasted peanuts along with their raw counterpart. DSC signals with complex shapes were obtained, containing not only the contributions due to the denaturation of the arachin and non-arachin (conarachin) protein fractions, but also the endothermic responses for the fatty and/or starchy fractions. This study investigates how the recorded DSC signals are affected by selected experimental factors, such as the type of DSC pans used, the choice of the reference, and the sample preparation. The results show that high-volume stainless-steel (HVSS) pans should be preferred to standard aluminum pans, for they allow adding a large amount of water to the sample, which appears to improve the resolution of the measurements and makes it possible to measure the denaturation temperature (ϴd) of peanut proteins. The use of HVSS pans does not require to choose a specific reference. The measurements can be performed as soon as the water is added to the sample. Waiting for water homogenization has no influence on the quality of the DSC signals in the case of peanut samples. Finally, it may be interesting to add NaCl to the hydrated samples, for it increases the intensity of the enthalpy measurement for arachin’s denaturation. With this set of parameters, DSC measurements can be successfully used to evaluate the integrity of peanut proteins before and after heat treatments, such as dry-roasting.
 
Article
Heat treatment and mechanical movement are the most common stressors that affect food material processing. A w/o/w emulsion is a promising system for delivering sensitive materials in food products and in reducing dietary fat content, but for wider uses, it is necessary to evaluate emulsion behaviour during food manufacturing. In the present study, we simulate heat (5 to 85 °C) and mechanical processes (shear rate 0.1 to 1000 s⁻¹) using rotational rheometry and describe changes in glucose encapsulation efficiency and droplet size of model w/o/w 20% emulsions prepared with 2.5 wt % PGPR (polyglycerol polyricinoleate) as lipophilic emulsifier in canola oil (oil phase) and distilled water or 10 wt % skim milk as an internal water phase stabilized or not by 3 types of carrageenan (0.5 wt %) and milk proteins as emulsifier. The comparison of w/o/w emulsions prepared with three specific types of carrageenan provides the important information on the suitability of the combination of specific carrageenan and internal water phase. It was found that model manufacturing did not influence the result encapsulation efficiency of all w/o/w emulsions significantly. We demonstrated that model w/o/w 20% emulsions were sufficiently stable for manufacturing, especially when skim milk was used with 0.5 wt % kappa carrageenan as the internal water phase. These samples subjected to manufacturing showed an encapsulation efficiency 53.97 ± 0.00% even after 4 weeks storage at 4 °C and droplet size (D[4, 3]) 39.04 ± 1.56 µm. So prepared w/o/w emulsions provided the demanded stability and could be part of functional food.
 
Mandarin-like hybrid varieties included in the study. (a) Clemenvilla, (b) Nadorcott, (c) Ortanique
Antioxidant capacity of mandarin juice by varieties and harvesting seasons. TE trolox equivalent, DPPH 2,2`-diphenyl-1-picrylhy-drazyl scavenging, TEAC Trolox-equivalent antioxidant capacity. In the same color, different superscripts (a–c and A–C) indicate that there are statistically significant differences (p < 0.05) between the values of each variety in the 2017–2018 and 2018–2019 seasons, respectively by each variety (1–2)
Pie charts of statistical correlation between the physicochemical characteristics of mandarin juice. The pie charts and color gradients illustrate the strength of each of the correlations (e.g., DPPH and TEAC). TPC total phenolic compounds, TF total flavonoids, AA ascorbic acid, TC total carotenoids, DPPH 2,2`-diphenyl-1-picrylhydrazyl scavenging assay, TEAC Trolox-equivalent antioxidant capacity
Differentiation of mandarin-like hybrid varieties according to the discriminant functions
Article
In this study, samples of mandarin-like hybrids (Clemenvilla, Nadorcott and Ortanique) from two harvesting seasons (2017−2018 and 2018−2019) were analyzed, to evaluate its differences in physicochemical characteristics and nutritional properties and establish the parameters that allow classify these citrus cultivars. Results showed that Clemenvilla juice had the highest concentration of total phenolic and ascorbic acid and are strongly correlated to its higher antioxidant capacity. Flavonoids were higher in Nadorcott samples. Large differences of total carotenoids were observed in juice analyzed. Varieties and harvesting seasons significantly influenced ( p < 0.05) the physicochemical properties, bioactive compounds content and antioxidant capacity of samples. The pH, flavonoids, ascorbic acid, DPPH and TEAC values were determined as predictor parameters to classify the groups according to the varieties, concluding that Nadorcott samples were clearly different. The data presented in this research will currently provide information about the physicochemical evaluation of mandarin-like hybrid varieties and their potential as source of bioactive compounds and antioxidant capacity.
 
Antioxidant activity determined by ABTS (A) and DPPH (B) assays in honeybee products from Poland
Bi-plot of PCA of TPC, TF, individual polyphenols and antioxidant properties (1–23 represent the number of polyphenols identified in the bee products, refer to Table 1)
Concentration (µg/g) of free (F) and conjugated (C) phenolic acids and flavonoids detected in honey bee products from Poland
Article
In this study, the profile of free and conjugated phenolic compounds and antioxidant activity of bee bread, bee pollen, honey and beeswax samples from the same beehive was analyzed. The contents of free phenolic compounds and those released from the esters and glycosides bounds were analyzed by HPLC–TOF–MS/MS method. In the obtained extracts, the total of phenolic (TP) and flavonoid (TF) contents was measured using spectrophotometric methods, while antioxidant activity was determined by DPPH and ABTS in vitro assays. Therefore, in the tested honeybee products 23 phenolic compounds were identified, constituting of 14 phenolic acids and nine flavonoids. Among the phenolic acids, ferulic (bee bread), protocatechuic (bee pollen) and m-coumaric acids (honey and beeswax) were predominant. In case of flavonoids, the major compounds were vitexin in bee bread, orientin in bee pollen, and apigenin in honey. The highest TP and TF contents were detected in the bee pollen, and was 4.11 mg GAE/g and 0.41 mg Q/g, respectively. Moreover, these compounds were mostly present in bound form. Honeybee product extracts had high scavenging ability against radicals, and their antioxidant activity differed significantly across samples (p < 0.05). Overall, this study demonstrates that selected honeybee products are an abundant source of the bioactive compounds with the characteristic profile of phenolic compound as well as antioxidant activity.
 
Average fatty acid profile in the tested nut and seed butters (% of total fatty acids). P—palmitic, S—stearic, A—arachidic, O—oleic, L—linoleic, Ln—linolenic acid. Error bars represent maximum and minimum determined values; significant differences (according to t-test) are indicated by different letters
Average acid (A), peroxide (B) and anisidine (C) values determined during the storage period at 21 °C of different nut and seed butter samples. Error bars represent minimum and maximum determined values. Storage time: S0—beginning of the experiment; S2—2 months; S4—4 months; S7—7 months; peanut STD—standard varieties; peanut HO—high-oleic varietes
The results of TAG oxidation product screening in peanut butter samples. A PCA score plot; B PCA loading plot; C profile chart for m/z 912.7543 (TAG C50:7 with four added oxygens); D profile chart for m/z 948.8450 (TAG C56:2 with two added oxygens); E extracted ion chromatograms for m/z 948.8450 showing a difference between high-oleic and standard peanut butter samples. Storage time: S0—beginning of the experiment; S2—2 months; S4—4 months; S7—7 months
α-Tocopherol peak areas determined in nut and seed butter samples by SFC-HRMS/MS at the beginning of the experiment. Significant differences (according to t-test) are indicated by different letters (Separately cashew sample 22 with 4% sunflower oil declared on packaging)
Article
  • Michaela RektorisovaMichaela Rektorisova
  • Monika TomaniovaMonika Tomaniova
  • Jana HajslovaJana Hajslova
Nowadays, pure nut and seed butters are a popular food category perceived as health-beneficial. However, only limited attention is paid to potentially toxic/antinutritional products of lipid oxidation. This study assessed lipid component quality and its changes in 40 different nut and seed butters (peanut; almond; hazelnut; walnut; cashew; sunflower, hemp, and pumpkin seed) available on the Czech market. Within the 7-month storage, acid values were stable or only slightly increasing except the walnut samples with up to 8× increase. Peroxide values varied depending not only on sample type, but also between individual samples; in general, cashew and hazelnut samples had the lowest peroxide values, while significant differences were found between peanut butters produced from high-oleic and standard peanut varieties. For a deeper insight into ongoing processes, triacylglycerol oxidation products were screened by supercritical fluid chromatography coupled to high-resolution tandem mass spectrometry (SFC-HRMS/MS). Moreover, fatty acid composition, determined by gas chromatography coupled to flame ionization detector (GC-FID), and TAG composition, profiled by SFC-HRMS/MS, were compared with the literature, and no adulteration by replacing/adding other than declared nuts/seeds was detected.
 
Turbiscan Stability index (TSI) obtained from the emulsion formulations prepared at a 10 MPa; b 50 MPa; c 100 MPa, d 200 MPa microfluidization pressure
Droplet size distribution (A) D[3,2] and (B) D[4,3] obtained from the emulsion formulations prepared at a 10 MPa; b 50 MPa; c 200 MPa; d 100 MPa microfluidization pressure
Zeta potential obtained from the emulsion formulations prepared at a 10 MPa; b 50 MPa; c 200 MPa; d 100 MPa microfluidization pressure
ΔE obtained from the emulsion formulations prepared at a 10 MPa; b 50 MPa; c 200 MPa; d 100 MPa microfluidization pressure
Degradation of vitamin A in emulsions prepared at a 10 MPa; b 50 MPa; c 200 MPa; d 100 MPa microfluidization pressure. All experiments were performed at 40 °C in the presence of oxygen and measured by HPLC–DAD
Article
  • Shahin BanasazShahin Banasaz
  • Ksenia MorozovaKsenia Morozova
  • Giovanna FerrentinoGiovanna Ferrentino
  • Matteo ScampicchioMatteo Scampicchio
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.
 
Protein profile of bee bread (BB, n = 8) and bee pollen (BP, n = 5) aqueous extracts. Aliquots (15 μl) of each extract were resolved by 12% SDS-PAGE and protein content assessed after gel staining with Coomassie Brilliant Blue R-250
Immunodetection of bee-derived proteinous compounds in BB and BP extracts. Aliquots (15 μl) of each extract were resolved by 12% SDS-PAGE and 16.5% Tricine-SDS-PAGE. After the wet blotting procedure, the blocked membrane was incubated overnight with a rabbit polyclonal antibody against honeybee (A) MRJP1, (B) GOX or (C) defensin-1. Immunoreactive bands were detected in solution containing dissolved SigmaFast 3,3-diaminobenzidine tablets. Red, blue and green arrows indicate MRJP1-immunoreactive, GOX-immunoreactive and defensin-1-immunoreacitve band, respectively
Antibacterial activity of bee bread (BB) and bee pollen (BP) aqueous extracts against different bacterial pathogens. Antibacterial activity was determined with a minimum inhibitory concentration (MIC) assay. Antibacterial activity of BB and BP extracts was expressed as an MIC value and calculated per unit of protein content in extracts. Data are expressed as mean values with standard deviation
Effect of glucose supplementation on antibacterial activity of bee bread (BB) and bee pollen (BP) aqueous extracts against Staphylococcus aureus and Pseudomonas aeruginosa. A Antibacterial activity of individual BB and BP samples was determined with a minimum inhibitory concentration (MIC) assay in MHB medium with or without 20 mM glucose. B Comparison of overall antibacterial activity of BB and BP extracts in MHB medium with or without 20 mM glucose (GLU). Antibacterial activity was expressed as an MIC value and calculated per unit of protein content in extracts. Data are expressed as mean values with standard deviation. *P < 0.05; **P < 0.01
Analysis of mechanistic antibacterial effect of selected BB and BP aqueous extracts against (A) Staphylococcus aureus and (B) Pseudomonas aeruginosa. BB and BP extracts were treated with catalase (2000 − 5000 U/mg protein) at a final concentration of 1000 − 2500 U/ml at room temperature for 2 h or proteinase K (30 U/mg) at a final concentration of 50 μg/ml at 37 °C for 30 min. Antibacterial activity was determined with a minimum inhibitory concentration (MIC) assay. Antibacterial activity of BB and BP aqueous extracts was expressed as an MIC value and calculated per unit of protein content in extracts. AE aqueous extract, Glu glucose, Prot-K proteinase K. *P < 0.05, ns non-significant
Article
Bee pollen (BP) and bee bread (BB) have attracted great attention due to their biological activities including antibacterial activity. However, the mechanism of antibacterial activity is largely unknown. Therefore, we aimed to characterise the antibacterial effect of BP and BB aqueous extracts against bacterial pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Enterococcus faecalis) and identify the key compound(s) responsible for this effect. Here, we demonstrate that BP and particularly BB extracts display antibacterial activity which is significantly increased in the presence of glucose. Immunoblot analysis of extracts revealed the presence of MRJP1 in all analysed BP and BB samples and the enzyme glucose oxidase (GOX) in the majority of BB samples. Treatment of extracts with catalase resulted in the restoration of bacterial growth but only in those samples where glucose supplementation caused the enhancement of antibacterial activity. Our findings provide a deeper understanding of antibacterial activity of BP/BB which is mediated by the enzymatic activity of bee-derived GOX.
 
The total polyphenols content in the cranberry jams
Antioxidant activity (DPPH and ABTS) of the cranberry jams
Article
Different form of seeds (whole or ground) may have a gelling effect and can substitute pectin in jams, moreover the type of their form have a remarkable impact on jams quality. The objective of this study was to ascertain if the form of added seeds have an influence on the physicochemical and antioxidant properties of cranberry jams incorporated in gold flax and chia seeds. Compared to traditional cranberry jam, the addition of both chia and gold flax seeds to the jams enhanced the nutritional value of samples by significant increase in protein, dietary fiber and polyunsaturated fatty acids content. Moreover, the enrichment of cranberry jams with seeds caused an increase in total polyphenols and phenolic acids content as well as their antioxidant activities. The texture measurement showed that both chia and flax seeds (irrespectively of their form) exhibited a gelling properties, however, the jams with the addition of ground seeds were characterized by similar texture as the control cranberry jam. Based on the obtained results, both gold flax and chia seeds can be considered as promising substitute for the gelling agents which additionally can change the physicochemical and antioxidant properties of jams.
 
UV–Vis spectra a CORW and CORB in pH = 3 and pH = 5, b CORW and CORB in the presence and absence of Fe⁺² in pH = 3 and c CORW and CORB in the presence and absence of Fe⁺² in pH = 5
FTIR spectra of β-cyclodextrin, CORW and CORB
CIELAB color parameters of treated Cornelian cherry extracts: a CORW in pH = 3, b CORB in pH = 3, c CORW in pH = 5, d CORB in pH = 5 and total color differences (ΔE) between treated extracts: e pH = 3 and f pH = 5. [Different letters indicate significant difference at 5% level in Tukey’s test (p < 0.05)]
Total color difference (ΔΕ) over 1 month of storage of acidic non-carbonated beverages; BC: beverage with CORW stored at 4 °C, BCB: beverage with CORB stored at 4 °C, BCE: beverage with CORW stored at 25 °C and BCBE: beverage with CORB stored at 25 °C
CIELAB color parameters of pork burgers: a redness (a*), b yellowness (b*) and c total color difference (ΔΕ) over 5 days of storage [Different letters indicate significant difference at the 5% level in Tukey’s test (p < 0.05)]
Article
The objective of this study was the production of green extracts from Cornelian cherry pomace and the valorization of their anthocyanin content for their potential use as food colorants. Aqueous solutions of β-cyclodextrin were used both as green extraction solvents as well as means of anthocyanins’ stabilization. The extracts were analyzed by a novel liquid chromatographic method coupled to triple quadrupole time-of-flight mass spectrometry analytical methodology (LC-QTOF-MS) to assess their anthocyanin content. FTIR spectroscopy was used to investigate possible interactions between cyclodextrin and Cornelian cherry’s anthocyanins. The stability of anthocyanins was evaluated under different pH conditions and in the presence of metal ion Fe⁺². The extracts were finally evaluated as colorants in two different food systems. The results showed that the color of β-cyclodextrin extract was preserved through storage. Additionally, the combination of β-cyclodextrin extraction and storage at low temperature contributes to the development of a stable acidic non-carbonated red beverage.
 
Valorization approaches of lemon peels to obtain potential bioactives
Contour plots illustrating the effect of the independent variables on YTP. The upper left, upper right and lower plots show the effect of simultaneous variation of aCw and RL/S, bCw and t, and cRL/S and t, respectively. Extractions of lemon peels was carried out under continuous stirring at 600 rpm, at 50 °C in a water bath
Contour plots illustrating the effect of the independent variables on ARS. The upper left, upper right and lower plots show the effect of simultaneous variation of aCw and RL/S, bCw and t, and cRL/S and t, respectively. Extraction of lemon peels was carried out under continuous stirring at 600 rpm, at 50 °C in a water bath
Phenolic acids quantification results (mg L⁻¹ ± SD): quercitrin; rutin; luteolin, diosmin; epicatechin; catechin; gallocatechin extracted by Water; MeOH; DES
Flavonoid quantification results (quercetin; quercitrin; rutin; luteolin, diosmin; epicatechin; catechin; gallocatechin) extracted by Water; MeOH; DES
Article
Extraction of polyphenolic compounds from lemon peels using deep eutectic solvents (DES) was investigated. A choline chloride-based DES paired with glycerol was used as the extraction solvent, alternative to conventional ones. Response surface methodology (RSM) was employed to optimize the extraction parameters, namely, the water concentration (CW), the liquid to solid ratio (RL/S) and the duration of the extraction (t) in terms of total phenol content and radical scavenging activity; the conditions that can be recommended as optimum for the recovery of the phenolic compounds were 55% (w/v), 13 mL g⁻¹ and 36 min, respectively. The composition of the obtained extracts under optimum conditions was compared with extracts prepared in ethanol and water. A novel reversed phase ultra-pressure electrospray liquid chromatographic time-of-flight mass spectrometric method (RP-UPLC–ESI–QTOF-MS) was developed and validated for the determination of individual bioactive compounds in the extracts through target, suspect, and non-target screening. The developed RP-UPLC–ESI–QTOF-MS methodology was validated and presented adequately low limits of detection (LODs) and limits of quantification (LOQs) over the ranges 8.64 (quercetin)–30.4 μg L⁻¹ (p-coumaric acid), and 25.9 (quercetin)–91.2 μg L⁻¹ (p-coumaric acid), respectively. The RSD% of the within-day and between-day assays were lower than 3.2, and 9.8, respectively, demonstrating good method precision. Overall, 10 compounds were determined and quantified through target screening, as well as 4 suspect, and 9 non-target compounds were tentatively identified in the extracts by means of suspect and non-target screening, respectively.
 
Article
Lipids are biochemical compounds that are substantially present in coffee beans. However, lipids in coffee have not been comprehensively studied thus far and have not been used to differentiate its geographical origin. This study aimed to investigate the applicability of lipid profiling for use in coffee origin authentication. In this study, Indonesian superior coffee originating from six major producing regions was used. Lipid extraction from roasted coffee was subjected to a high-performance liquid chromatography coupled with triple-quadrupole mass spectrometry (LC–MS/MS). The obtained data were analyzed using the multivariate approach, including partial least squares discriminant analysis (PLS-DA), principal component analysis, and clustering analysis. The LC–MS/MS analysis tentatively identified 85 lipid species from five global lipid classes, such as neutral lipids, sphingolipids, sterol, glycerophospholipids, and glyceroglycolipids. The PLS-DA model exhibited an accuracy of 90%–100% in discriminating the origins of coffee based on receiver operating characteristics–area under the curve analysis. Therefore, the lipid profile obtained from the LC–MS/MS analysis can be applied to determine the geographical origin of coffee. The selected features showed high reliability as descriptor compounds in the validation analysis, as indicated on the natural separation of the unsupervised model. The results of this research provide solid evidence for the discrimination of the origin of coffee based on its lipid profile. Moreover, it might benefit the coffee industry to establish an advanced method for determining the origin of coffee.
 
Weight loss (%) of fresh cut Formosa papaya during cold storage at 6 °C with different coatings
Evolution of color parameters: a Lightness; b Hue angle; c Chroma; d Overall color changes (∆E), on fresh cut Formosa papaya during cold storage at 6 °C with different coatings
Changes in sugar content during the storage period: a Glucose content; b Fructose on fresh cut Formosa papaya during cold storage at 6 °C with different coatings. At time 0 the value of 100% was considered, to make the variations more understandable
Principal component analysis (PCA) of sugars, color parameters and volatile compounds in fresh cut Formosa papaya and after 14 days of cold storage at 6 °C with different coatings
Article
Active alginate-based coatings with quercetin glycoside and complexes of hydroxyapatite/quercetin-glycoside were used to study the shelf life of fresh cut papaya stored at 6 °C. Hydroxyapatite was used as a carrier for the release of the bioactive compound. The parameters considered affecting the quality of the fruit during storage were weight loss, color, texture, sugars and volatile compounds. Active coatings with hydroxyapatite and quercetin glycoside proved a higher capacity to slow down the degradation phenomena studied, showing less weight loss, a lower reduction in glucose and fructose, as well as better firmness, than the other samples after 14 days of cold storage. Benzyl isothiocyanate, the characteristic odor compound of papaya fruit, ranged from approximately 10.0 μg/kg in fresh cut fruit to approximately 7.50 μg/kg in samples coated by alginate with hydroxyapatite/quercetin and 3.6 μg/kg in the fresh cut papaya without coating after 14 days of cold storage. The trials also indicated greater effectiveness of alginate coatings alone and with quercetin-glucoside in preserving the color of freshly cut papaya.
 
Derivatization time on the derivatization reaction
Recovery rate on different derivatization time
Selective ion chromatogram for CPAOZ, CPAMOZ, CPSEM, CPAHD at level of 2.5 μg kg⁻¹
Article
Nitrofurans, a kind of banned antibiotics for their serious toxic side effects, have often been found in aquatic products in the past and are still found nowadays which were a severe threat for human health. A rapid quantization of nitrofuran metabolites residues in aquatic products by ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was developed in this study. The experimental operation consisted of an acid-catalyzed release of protein-bound metabolites, followed by derivatization with 2-chlorobenzaldehyde (2-CBA) and then extraction with ethyl acetate before analysis by positive electrospray ionisation (ESI⁺) with multiple reaction monitoring (MRM) type. 2-CBA was employed as derivatization reagent in this study, which greatly reduced the derivatization time. The linearity range for the four analytes were 0.25–50 μg kg⁻¹ with good determination coefficients (R² > 0.9982). The limit of detection (LOD) were 0.1 μg kg⁻¹, 0.1 μg kg⁻¹, 0.3 μg kg⁻¹, 0.3 μg kg⁻¹ and the limit of quantification (LOQ) were 0.3 μg kg⁻¹, 0.3 μg kg⁻¹, 0.9 μg kg⁻¹, 0.9 μg kg⁻¹ for AOZ, AMOZ, SEM, and AHD, respectively. Recovery rates were ranged from 90% to 114% for fortified samples at levels of 1.0 μg kg⁻¹, 5.0 μg kg⁻¹ and 10 μg kg⁻¹ with relative standard deviation values ranging from 1.6% to 5.8%. The developed method was successfully applied in 100 aquatic products for NFs metabolites detection and the results were further confirmed by the national standard GB/T 21311-2007 method.
 
Article
There are many types of haricot beans, the nutrient consumed all over the world. Each type differs in terms of features such as taste, size, economic value, etc. But even if they are different types, bean grains are frequently confused with each other. For these reasons, it is important to separate the bean grains of different species. For this purpose, a haricot bean dataset consisting of 33,064 images of 14 different bean types was created. By using these images, 3 different pre-trained Convolutional Neural Networks (CNN) were trained via the transfer learning method. Within the scope of the study, InceptionV3, VGG16, and VGG19 CNN models were used. These models were utilized for both end-to-end classification and extraction of image features. Firstly, the images were classified via Inception V3, VGG16, and VGG19 models. As a result of this classification, 84.48%, 80.63%, and 81.03% classification success were obtained from InceptionV3, VGG16, and VGG19 models, respectively. Secondly, the image features of these 3 models were taken from the layer just before the classification layer. Then, these features were given as input to the Support Vector Machine (SVM) and Logistic Regression (LR) models. Images were classified using six different models, InceptionV3 + SVM, VGG16 + SVM, VGG1 + SVM and InceptionV3 + LR, VGG16 + LR, VGG1 + LR. Classification successes obtained from InceptionV3 + SVM, VGG16 + SVM, and VGG19 + SVM were 79.60%, 81.97%, 80.64%, respectively. And, the classification successes obtained from InceptionV3 + LR, VGG16 + LR, and VGG19 + LR were 82.35%, 83.71%, and 83.54%, respectively. The InceptionV3, among all models, was determined to be the best classification model with a classification success of 84.48%. On the other hand, the model with the lowest classification success was determined to be the InceptionV3 + SVM. Detailed analysis of the created models was also carried out with precision, recall, and F-1 score metrics. It is thought that the proposed models can be used to distinguish haricot bean types in a quick and accurate way. Furthermore, the proposed computer vision methods can be combined with robotic systems and used to the distinction of bean types. By means of image processing, varieties can be determined on conveyor belts, and dry bean varieties can be purified with delta robots.
 
Storage modulus (G′) and loss modulus (G″) of Tween 20 and soy lecithin solutions
Interaction plots (mean ± 95% confidence interval). A and B Interactions between the pressure and number of cycles for the MDD of nanoemulsions formulated with Tween 20 and lecithin, respectively. C and D Interactions between the pressure and number of cycles for the PDI of nanoemulsions formulated with Tween 20 and lecithin, respectively. E and F Interactions between the pressure and number of cycles for the thermal stability of nanoemulsions formulated with Tween 20 and lecithin, respectively. Different capital or lower case letters above bars indicate significant differences between samples (p < 0.05)
Contour plot for the impact of the processing parameters to the properties of the emulsions for Tween 20 stabilised emulsion (a–b) and soy lecithin-stabilised emulsion (c–d)
Article
Extra virgin olive oil-in-water nanoemulsions stabilised with synthetic or clean label surfactants (Tween 20 or soy lecithin) was prepared using high-pressure homogenisation (HPH). The effect of HPH pressure and the number of cycles were assessed through response surface methodology to optimise homogenisation processing parameter. Mean droplet diameter (MDD), polydispersity index (PDI), thermal stability and oxidation stability of the resulting emulsions were evaluated. The results showed that the formation and stability of nanoemulsions can be affected by the homogenisation processing parameters (pressure and cycles) and the properties of surfactants (interfacial tension, viscoelasticity and molecule structure). Although MDD and PDI of Tween 20 stabilised nanoemulsions were influenced by homogenisation pressure and cycles, there was not a significant effect on lecithin-stabilised nanoemulsions. A homogenisation pressure of at least 400 bars produced Tween 20 stabilised nanoemulsion (MDD < 200 nm), whereas lecithin-stabilised nanoemulsion were obtained after high-speed homogenisation without using HPH. HPH at 400 bars for 1 cycle produced nanoemulsions with greater physical stability when using either Tween 20 or lecithin. Tween 20 stabilised nanoemulsion showed significantly higher ( p < 0.05) thermal stability and lipid oxidative stability than lecithin-stabilised nanoemulsion. Following an optimisation study using regression modelling, the optimal homogenisation parameter for MDD of Tween 20 stabilised emulsion was found at pressure of 764 bars with 1 cycle, while lecithin-stabilised emulsion was found at pressure of 3 bars with 2 cycles. Overall, this study has important implications for optimising nanoemulsion production for potential application in the food industry.
 
a Venn diagrams showing the overlap in DEPs between the three groups of blackberries (N/C, F/C, and F_N/C). Shown is the total number of significantly differentially expressed proteins. b The number of DEGs in F_N/C group (c). The histogram shows the number of up-regulated and down-regulated differentially expressed proteins in each group. The pie chart shows the distribution of the functionally annotated or unchartered proteins in value and percentage
Bioinformatics analysis of characterized genes and proteins through Gene Ontology (GO) in three domains: molecular function, biological process, and cellular component
Functional clustering of DEGs and DEPs in F_N/C group. DEGs: differentially expressed genes, DEPs: differentially expressed proteins
The gene expression in common DEGs and DEPs; the combination of ferulic acid and natamycin compared the control group determined by transcriptomic, proteomic analysis and qRT-PCR. GPAPCL: glyceraldehyde-3-phosphate dehydrogenase cytosolic-like, MAD: malate dehydrogenase, GEbD: glucan endo-1,3-beta-glucosidase, HSPAL: heat shock 70 kDa protein-like, NACaL: nascent polypeptide-associated complex subunit alpha-like, AtpB: ATP synthase subunit beta, mitochondrial, MPG: mannose-1-phosphate guanylyltransferase-like, COX6: cytochrome c oxidase subunit 6
Overview of the main metabolic pathway and possible roles in identified DEGs and DEPs in combination of ferulic acid and natamycin group compared to control (F_N/C). All genes were down-regulated, with black boxes representing DEPs and DEGs, green square boxes representing DEPs and elliptical boxes representing DEGs. EMP, Embden − Meyerhof − Parnas; TCA, tricarboxylic acid cycle; ETC: electron transport chain. ACLY: ATP citrate lyase (ACL) family protein; DLST: Dihydrolipoamide succinyltransferase; LPD: lipoamide dehydrogenase; MDH: Malate dehydrogenase; DLAT: Dihydrolipoamide acetyltransferase; GAD: Glutamate decarboxylase; LACS1: long-chain fatty acyl-coenzyme A synthetase1; ACX1: acyl-CoA oxidase 1; FDH: formate dehydrogenase (NAD +); AlaAT: alanine aminotransferase; GR: glyoxylate reductase; ACS: acetyl-CoA synthetase; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; ALDH: aldehyde dehydrogenase; PK: pyruvate kinase; ENO: enolase; PFK: phosphofructokinase; PGM: phosphoglucomutase; PFP: pyrophosphate-fructose 6-phosphate 1-phosphotransferase subunit beta 2; COX6: cytochrome c oxidase subunit 6; QCR7: cytochrome b-c1 complex subunit 7-like; ndhD: NADH dehydrogenase; GPX: glutathione peroxidase; β-Glu: beta glucosidase; L-DES: L-cysteine desulfhydrase; SAHH: S-adenosyl-L-homocysteine hydrolase; FBA: fructose-bisphosphate aldolase; PDH: pyruvate dehydrogenase; Aco: aconitate hydratase
Article
The results of previous studies have shown that the combined treatment of ferulic acid and natamycin has a good effect on maintaining the quality of blackberries. However, the molecular mechanism by which increasing firmness and quality of blackberry fruits induced by blackberry preservation has not been elucidated. Therefore, the objective of the work was to detect the metabolic changes of blackberry treated with ferulic acid and natamycin jointly using RNA-Seq and iTRAQ protein quantification methods. The combined ferulic acid and natamycin treatment compared to the control group contained 439 and 388 differentially expressed genes (DEGs) and differentially expressed proteins (DEPs), respectively, of which 414 DEGs and 387 DEPs were down-regulated. They were mainly catalytic activity and binding genes and proteins, and most involved in metabolic process and cellular process, molecular function of organelle and cell part. It was also revealed that combined treatment of ferulic acid and natamycin could inhibit the carbohydrate metabolic, energy metabolism bioprocess, amino acids biosynthesis, weaken the respiration, and improve its resistance to stress, resulting in the fruit defense capability, further extended shelf life of fresh blackberry.
 
Portions of tocopherol compounds
Correlation between oxidative stability with different minor compounds and acidic composition
Hierarchical cluster analysis heatmap. This hierarchical clustering was constructed based on Euclidean distance. Content is shown by the color scale. Green for high value, red for low level and the black for intermediary value
PCA plot of the studied olive oils using the whole data set obtained
Article
The selection of new olive cultivars with a good oil quality among feral olives may be considered as a way to diversify our olive genetic resources and to select new cultivars for oil production under Tunisian conditions. This study was carried out to determine phenolic and tocopherol compounds, pigments, oxidative stability, triacylglycerol, and fatty acid compositions of unstudied feral olive oils, and a comparison was made with the Chemlali cultivar, the most common Tunisian variety. Results demonstrated that the profiles of feral oils were distinctly different from those of cultivated Chemlali oil. All results indicate that there is a wide variability in the chemical characteristics of the studied oils. Our results showed that F3 feral olive oil was characterized by high mean values of total phenols (1073 mg kg⁻¹) and oxidative stability (88.4 h). The cultivar genotype factors might explain variability in phenols (105–1074 mg kg⁻¹), tocopherol (324–844 mg kg⁻¹), C18:1 (57–78%), oxidative stability (26–105 h), and the profiles of triacylglycerol in investigated extra virgin olive oils (EVOOs). HPLC-ESI-MS analyses showed that F3 olive oil contains appreciable amounts of alcohols (399 mg kg⁻¹) and high concentrations of secoiridoid derivatives (SID) (545 mg kg⁻¹). Therefore, tocopherol analysis revealed the presence of α-, β-, γ-, and δ-tocopherols in all the studied olive oils. As for total tocopherols, the amount of each tocopherol varied according to genotype. α-tocopherol is the most abundant, whereas β-, γ-, and δ-tocopherols are less represented. Besides, the results demonstrated the great influence of total phenols and tocopherols on the stability of virgin olive oil (R² = 0.9027, R² = 0.901, P < 0.05, respectively). Additionally, the statistical analyses (PCA and HCA) can explain the variability of the oil composition according to the cultivar. The feral olive oils constitute a new edible oil source characterized richer in natural bioactive components.
 
Identification percentages of different chemical classes emitted by studied oils using SPME–GC–MS
Identification percentages of different groups of non-terpenes derivatives (NTD) compounds emitted by studied oils using SPME–GC–MS
Distribution of C6 compounds in relation to total volatile compounds
Principal component analysis applied to volatile compounds
Dendrogram of volatile data using Euclidean distance
Article
Fruits from the same cultivar of Olea europaea L. cv. Chaaibi were picked at the same ripeness stage and processed quickly across varied environmental conditions in Tunisia. Solid-phase micro-extraction (SPME) coupled with gas chromatography–mass spectrometry (GC–MS) were used to determine the aroma profile of virgin olive oils. The volatile profiling was mostly constituted of compounds from the following chemical classes: esters, aldehydes, alcohols, and hydrocarbons. Significant variances in the percentages of volatile constituents in oils from diverse geographical origins were discovered, with the aldehyde (E)-2-hexenal being the predominant volatile in almost half of the oil samples. The findings imply that, in addition to genetics, growing area impacts aroma composition. Remarkably, the proportions of volatile compounds and fatty acid compositions in oils collected from different growing areas exhibited strong variability. These findings can be utilized to distinguish and describe Chaaibi olive oils from various areas.
 
Principal Component Analysis (PCA) of GBVs of Roasted CB; Green CB; SCG (Spent Coffee Ground)
Article
Coffee volatile compounds formation has been studied for years and the main flavour precursors have been identified. Coffee glycosidically bound volatiles (GBVs) are still underexplored and, yet, can act as aroma precursors during the post-harvesting processing and roasting. Free volatile compounds and GBVs of green coffee beans (CB), roasted CB and spent coffee ground (SCG) were analysed. Roasting led to the formation of a new GBVs pool from green to roasted CB and SCG. Most of the GBVs of green CB were hydrolysed during roasting. On the other hand, pyrroles, cycloketones, pyridines and pyrans were identified for the first time as bound volatiles and occurred only after the roasting process. This study supports the importance of GBVs on coffee aroma formation during the post-harvest processing. The release of the GBVs of roasted CB during brewing could enhance the varietal aromas of industrial ready-to-drink coffees. Furthermore, the SCG GBVs could be used as a new source of natural flavours for perfume industries.
 
Growth of Pseudomonas fluorescens RM3 in milk samples inoculated at A high (1.80 × 10³ cfu/mL), B medium (8.40 × 10² cfu/mL), and C low level (2.00 × 10¹ cfu/mL) and incubated at 25 (red line) or 4 °C (blue line). The visual appearance of samples and the outcome of the thermal stability test are shown
Caseinomacropeptides (corrected peak area) in milk inoculated at high (1.80 × 10³ cfu/mL), medium (8.40 × 10² cfu/mL) and low (2.00 × 10¹ cfu/mL) level and incubated at 25 (red line) or 4 °C (blue line)
Sequence of microstructural changes observed by CSLM during gelation of milk inoculated at high level (1.80 × 10³ cfu/mL) and incubated at 25 (A) or 4 °C (B). Protein is green and fat is red. Blue image frame indicates liquid sample, while red image frame indicates gelled sample. Bars are 10 µm in length
Comparison between microscopic (left) and visual appearance (right) of milk during gelation (low inoculation level, incubation at 25 °C). A–A’ Native microstructure-liquid milk; B–B’ small nuclei of aggregated protein–liquid milk; C–C’ network of destabilized protein-gelled milk; D–D’ contraction of protein network separation of whey. Bars in CLSM images are 10 µm in length
CLSM of aggregated protein (arrows) observed in milk still liquid (low inoculation level, incubation at 25 °C for 24 h). Protein in A, A’ is green, fat in B, B’ is red, bacteria in C, C’ are blue. Bacteria are co-localized with fat globules and protein within the nuclei of aggregated protein (D). The framed nuclei of aggregated protein are enlarged in A’–D’ for the respective channels. Bars in CLSM images are 10 µm in length
Article
Heat–stable peptidase AprX, released by Pseudomonas species in raw milk during cold storage, can cause gelation of UHT milk since it is able to split caseinomacropeptides (CMP tot ) from κ-casein, so inducing aggregation of casein micelles. Identifying raw milk susceptibility to gelation would allow UHT milk manufacturers to select appropriate processing conditions or give the milk a different destination. Two approaches, i.e., detection of free CMP tot and evidence of casein aggregates, were evaluated as possible indicators for early detecting milk destabilization. With this aim, microfiltered milk was inoculated with a P. fluorescence strain and incubated at either 4 or 25 °C. The presence of CMP tot was detected using capillary electrophoresis after 96 and 24 h at the two temperatures, respectively, when milk also became heat unstable and small flocks of protein appeared. Confocal laser scanning microscopy evidenced initial aggregates of casein micelles after 48 and 24 h at 4 and 25 °C, respectively. Keeping the milk at 25 °C/24 h could be a useful condition to accelerate milk destabilization. Despite the similar timing of instability detection, presence of CMP tot was the only trait specific for AprX activity.
 
Schematic diagram of the SERS-based LFA for simultaneous detection of NEO and LIN (a), and the SERS detection of test line (b)
Representative SEM images and Raman spectra from the test lines of the negative sample (a, c) and strong positive sample (b, d)
The specificity assay of SERS-based LFA
Optimization of experimental conditions. a, b The amount of mAbs; c, d the concentration of coating antigens; e, f the concentration of SERS immunoprobes
a The list of NEO and LIN at different concentration levels; b SERS spectra for the simultaneous detection of NEO and LIN with different concentrations; c the standard curve of NEO; d the standard curve of LIN
Article
Neomycin and lincomycin are widely used in the treatment of infections illnesses. However, the irrational and inappropriate of antibiotics contributes to threaten human health seriously. We developed a rapid and multiple detection strategy for trace amounts of neomycin (NEO) and lincomycin (LIN) in milk using Surface-Enhanced Raman Spectroscopy (SERS)-based lateral flow assay (LFA). The method used two SERS immunoprobes (a probe for NEO and a probe for LIN) were mixed and applied to the conjugate pad, and then, the NEO-OVA and LIN-OVA were mixed and coated on LFA as the only test line. Simultaneous quantitative detection of NEO and LIN was achieved by detecting the Raman intensity of captured immunoprobes on test line using a Raman spectrometer. Under optimized condition, NEO and LIN could be detected as low as 0.33 pg/mL and 0.29 pg/mL in 15 min with a sample volume of 100 μL. The practicality of the LFA in milk sample was also validated. The method is highly sensitive, accurate, and effective. It has a good chance to be employed for multiple antibiotics detection in food products.
 
Expression of CPM32 in B. subtilis. A Growth and expression of recombinant B. subtilis. B SDS-PAGE analysis of the purified CPM32 from B. subtilis. The carboxypeptidase activity was determined in 50 mM Tris–HCl buffer (pH 7.4) at 37 °C using Z-Glu-Tyr as the substrate. Lane M, protein markers; lane 1, control group; lane 2, crude enzyme; lane 3, purified enzyme
Different signal peptides on the expression of CPM32 in B. subtilis. A Carboxypeptidase enzyme activity at different signal peptides. B SDS-PAGE analysis of CPM32 with different signal peptidases from B. subtilis. lane 1, CPM32; lane 2, CPM32 with signal peptidase AprE; lane 3, CPM32 with signal peptidase AmyQ; lane 4, CPM32 with signal peptidase NprB. *p < 0.05, #p < 0.05, compared with control, Duncan's test. n = 3
Effects of pH and temperature on the activity and stability of CPM32. A Optimal pH, the optimal pH was determined at 37 °C in 50 mM different buffers within the pH range of 5.0–10.0. The buffers used are Citric acid buffer (filled square, pH 5.0–6.5), Phosphate buffer (filled diamond, pH 6.5–9.0), Glycine–sodium hydroxide (filled circle, pH 9.0–10.0). B pH stability, the pH stability was evaluated by measuring the residual activity after the enzyme was treated at 37 °C for 30 min in various buffers mentioned above. C Optimal temperature, the optimal temperature was examined in 50 mM Tris–HCl buffer (pH 7.4) at different temperatures (30–90 °C). D Thermostability, the thermostability was evaluated by measuring the residual activity after the enzyme was treated in 50 mM Tris–HCl buffer (pH 7.4) at different temperatures (30–90 °C) for 2 h
Flavour analysis of SPI. A Radar map showing the sensory attributes of SPI. The taste profile of SPI was presented in each map for comparison. Each value represents the average sensory scores rated by the electronic tongues. *p < 0.05, **p < 0.01, compared with SPI, Student’s t-test. n = 3. B Heat map illustrating the free amino acid composition of CPM32 linked alkaline hydrolysis SPI. SPI, soybean protein isolate; TFAAs, total free amino acids; TBAAs, total bitter amino acids, including Ser, His, Arg, Val, Met, Ile, Leu, and Phe
Article
A carboxypeptidase M32 (CPM32) gene (cpm32) from Bacillus megaterium was cloned. CPM32 exhibited the highest sequence similarity of 79.3% with the same from Priestia veravalensis. CPM32 was fused with the signal peptides AmyQ (SPamyQ), AprE (SPaprE), NprB (SPnprB) in Bacillus subtilis WB600, and the highest CPM32 activity of 5320 U/mL was achieved when it was fused with SPamyQ. The purified enzyme (CPM32), 58.6 kDa, was most active at pH 8.0 and 60 °C, respectively, and it was stable over a broad pH range of 5.0–9.0 and an extensive temperature of 30–60 °C. Co²⁺ and Zn²⁺ could activate the enzyme activity by 600% and 334%, respectively. CPM32 could cleave most amino acid residues except Pro from chain's C-terminus. N-benzyloxycarbonyl-l-phenylalanyl-l-tyrosine (Z-Phe-Tyr) was the optimal substrate, for which CPM32 exhibited Km 0.6 mmol/L and kcat/Km 82.2 L/mmol s. Debittering soybean isolates using CPM32 (supplemented with 4% alkaline protease, w/w) resulted in a reduction in bitterness value of 47.6% to a commercially acceptable level. Applied to the hydrolysis of soy isolate protein, the bitterness of the hydrolyzates is significantly reduced and the flavor of the soy protein isolate hydrolysates is effectively improved.
 
a PCA plot of honey samples. b Volatile compound loadings of the PCA analysis for PC1 and PC2. Compounds are shown with RI (retention index)
Article
Twenty four honey samples of eight distinct botanical origins obtained from different regions of Turkey were analyzed in this study. Various physicochemical (glucose and fructose content, color, diastase activity, electrical conductivity, optical rotation, moisture and proline content), biochemical (total phenolic content, total flavonoid content, FRAP antioxidant capacity and DPPH radical scavenging activity) and volatile analytical methods were used for floral authentication of the honeys. Identification of 103 volatile compounds from different chemical classes was carried out using SPME/GC/MS. The availability of physicochemical and volatile identification methods, instead of melissopalynology which is dependent on the researcher’s ability and judgment regarding honey classification, was investigated. The results were statistically processed, and principal component analysis (PCA) was applied. The first two principal components explained 98.10% of the total variance, and the PCA produced eight different groups rhododendron, chestnut, lavandula, astragalus, chaste tree, polyfloral, oak, and pine honeys, each corresponding to a distinct botanical origin. Polyfloral honeys formed a cluster, although those samples were rather widespread. The studied honeys exhibited specific volatile compounds and biochemical properties which may be capable of use as floral markers.
 
Structure of major anthocyanins
Typical chromatograms of double blank blood sample (A), LLOQ blood sample and internal standard (B), ULOQ blood sample (C) and plasma samples from SD rat after administration of blueberry anthocyanins extract (D) are shown. I–V represent D3G (I), M3G(II), M3A (III), P3A (IV), D3A (V) and prunin (IS) respectively
Mean plasma concentration–time profiles of anthocyanins after oral administration of 270 mg/kg ‘Lanmei 1’ blueberry anthocyanins extracts in healthy SD rats (n = 8; Mean ± SD)
Bile concentration–time profiles of anthocyanins after oral administration of 270 mg/kg ‘Lanmei 1’ blueberry anthocyanins extracts in healthy SD rat (n = 3; Mean ± SD)
Article
As a major class of phenolic compounds, anthocyanins are the functional components of blueberry. Vaccinium corymbosum ‘Lanmei 1’ is a novel blueberry variety and detailed study of their anthocyanins remains scarce. Therefore, a simultaneously quantitative method for five anthocyanins using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was established here. Good linear relationships were obtained ranging from 1 to 100 ng/mL (R² > 0.99). In addition, the specificity, recovery, stability, and matrix effect met requirements of analytical methodology. The method successfully monitored the concentrations of five anthocyanins in plasma and studied their pharmacokinetics after oral administration of 270 mg of anthocyanin extract in Sprague–Dawley rats. Pharmacokinetic parameters for delphinidin-3-O-glucoside (D3G), malvidin-3-O-glucoside (M3G), malvidin-3-O-arabinoside (M3A), delphinidin-3-O-arabinoside (D3A), and petunidin-3-O-arabinoside (P3A) showed the similar short Tmax 0.25–0.28 h and medium speed T1/2 3.24–3.52 h. It indicated anthocyanins were quickly absorbed and taken effectively, but eliminated in blood at an appropriate rate. Contents of D3G and M3G in anthocyanin extract are approximately equivalent, while the total amount and maximum concentration of M3G were twice those of D3G in plasma. This demonstrated that there were many differences between the substance contents of anthocyanin monomers in vitro and their absorption and distribution behaviors in vivo. Multiple peaks in both concentration–time profiles and bile excretions for five anthocyanins suggested the possibility of enterohepatic circulation in rats. The present study developed and validated a rapid and sensitive bioanalytical method based on UPLC–MS/MS for quantifying major anthocyanins from a novel blueberry extract in rat plasma to further understand their absorption, distribution, and metabolism.
 
Article
Determining the variety of wheat is important to know the physical and chemical properties which may be useful in grain processing. It also affects the price of wheat in the food industry. In this study, a Convolutional Neural Network (CNN)-based model was proposed to determine wheat varieties. Images of four different piles of wheat, two of which were the bread and the remaining durum wheat, were taken and image pre-processing techniques were applied. Small-sized images were cropped from high-resolution images, followed by data augmentation. Then, deep features were extracted from the obtained images using pre-trained seven different CNN models (AlexNet, ResNet18, ResNet50, ResNet101, Inceptionv3, DenseNet201, and Inceptionresnetv2). Support Vector Machines (SVM) classifier was used to classify deep features. The classification accuracies obtained by classification with various kernel functions such as Linear, Quadratic, Cubic and Gaussian were compared. The highest wheat classification accuracy was achieved with the deep features extracted with the Densenet201 model. In the classification made with the Cubic kernel function of SVM, the accuracy value was 98.1%.
 
Chromatogram profiles of beers: Heraclea (blanche with bergamot juice extract, blue), basal Blanche (green), Elais (Weiss with olive extract, red), and basal Weiss (black)
Pearson’s correlations (r) between phenols (a), flavonoids (b), and antioxidant activities. The boxed dots show the significant correlations between values, and the color shows the level of correlation (yellow-boxed dots p < 0.05, green-boxed dots p < 0.01). The red dots indicate negative correlation
Odor maps fingerprints of beers: Heraclea (blanche with bergamot juice extract), basal Blanche, Elais (Weiss with olive extract), and basal Weiss, with Heracles system equipped with two parallel non-polar column (MXT-5) and slightly polar column (MXT-1701): a E MXT-5-FID1 + E MXT-1701-FID2; b EC MXT-5-FID1 + EC MXT-1701-FID2; c H MXT-5-FID1; d H MXT-1701-FID2 + HC MXT-5-FID1 + HC MXT-1701-FID2
Article
Citrus bergamia and Olea europaea L. variety Carolea are accounted as niche functional food for their high content of bio active compounds. Their extracts were used as adjunct to produce two beers with different styles, Blanche and Weiss, rich in antioxidants for a pool of consumers interested in a healthy lifestyle. The nutraceutical properties of these two beers were compared to Blanche and Weiss without any addition to verify if the beers enriched with natural extracts changed their aromaticity, flavors, and functionality. The antioxidant activity changed in the order: blanche bergamot beer > Weiss olive beer > blanche basal beer > Weiss basal beer. The phenolic profile of bergamot beer was qualitatively and quantitatively the richest in bio-compounds. Pearson’s correlation evidenced that total phenols contained in bergamot and olive beers were positively and significantly correlated with the antioxidant activities and precisely, with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total antioxidant capacity (TAC). Correlation data evidenced that the bergamot was the beer with the greatest antioxidant activity and bioactive compound amount. This study highlighted as the addition of these natural extracts together with the right productive process improved sensorial beer properties, satisfying consumer taste while potentially increasing the beneficial effects on human health.
 
Effect of heating on peroxide value (a), carbonyl value (b), and acid value (c) in grass carp oil
a Kinetic products of oxygen addition to oleate and linoleate carbon radicals. b Kinetic products of oxygen addition to arachidonic acid carbon radicals. c Proposed chemical mechanisms of volatile species formation from oxidized metabolites of PUFAs
Multivariate data analysis by Metaboanalyst 5.0 software. a PCA score plot of volatile species acted on Table 3. b VIP scores of volatile species acted on Table 3. c Heat map of the volatile species acted on Table 3
Article
The mechanisms of volatile species formation for hydroperoxylated metabolites of unsaturated fatty acids in grass carp oil were investigated. All oil samples were heated at 110 °C for 8 various durations. The hydroperoxylated metabolites were evaluated by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry, solid-phase microextraction gas chromatography mass spectrometry and conventional chemical indicators. Compared to fresh fish oil, the content of monounsaturated fatty acids and saturated fatty acids with higher oxidation stability in the heating samples was significantly increased (P < 0.05), while the content of polyunsaturated fatty acids was significantly reduced (P < 0.05). A total of 35 triglycerides were determined, of these, the relative content of carbon numbers (CNs) 54, 56 and 58 was dramatically decreased, while CN50 and CN52 were gradually increased. Partial least-squares discriminant analysis indicated that continuous heating had different effects on volatile substances and twelve volatile species variables associated with lipid oxidation from the eight various heating periods were identified. In addition, sixteen oxidized metabolites were identified and their content was significantly increased (P < 0.05), except the 13-HODE, 9-HOTrE, 5-HETE and 12-HETE. The metabolic pathways of grass carp oil under continuous heating were clarified based on critical volatile components and oxidized metabolites, intending to reveal the oxidation paradigm of oil exposed to high temperatures.
 
Article
For peanuts, roasted at 170 °C, the formation of selected glycerol-bound oxidized fatty acids (GOFAs), namely 9-oxononanoic acid (9-ONA), azelaic acid (AZA) and octanoic acid, was observed by GC-MS (EI). The content of octanoic acid as well as AZA increased with continuous roasting time (from 59 mg/kg peanut oil to 101 mg/kg peanut oil and from not detectable to 8 mg/kg peanut oil, respectively), whereas the content of 9-ONA initially decreased from 25 mg/kg peanut oil to 8 mg/kg peanut oil (20 min) and increased again up to 37 mg/kg peanut oil following roasting for 40 min. Due to its aldehyde function, 9-ONA could contribute to amino acid side chain modifications as a result of lipation, which could directly influence the functional properties of peanut proteins. Both 9-ONA and octanoic acid are potential markers of thermal processes. Furthermore, in model experiments using methyl linoleate and methyl oleate, up to 18 oxidized fatty acids could be identified as methyl esters, 9-ONA as well as octanoic acid as major components and a faster formation of GOFAs under roasting conditions (170 °C, 20 min). In addition, 9-ONA contributes to the formation of AZA and octanoic acid in both free and bound form as a result of oxidative subsequent reactions in presence of iron (III).
 
Article
Peptides with xanthine oxidase (XOD)-inhibitory activities are potential dietary interventions for the treatment of hyperurice-mia and gout. In this study, Macadamia integrifolia antimicrobial protein 2 (MiAMP2) was chosen for in silico proteolysis with pepsin, trypsin and chymotrypsin through ExPASy PeptideCutter, and the obtained peptides were further screened by water solubility, ADMET prediction and molecular docking. Four novel peptides, namely RPLY, PGPR, HGGR and GPY, were supposed to be non-toxic and have XOD-inhibitory potential. Molecular docking analysis showed that these peptides were able to bind to the active sites (such as Leu873, Phe914 and Thr1010) of XOD through interactions mainly including conventional hydrogen bond, alkyl and pi-interaction. These peptides were further synthesized to verify their in vitro XOD-inhibitory activities, and the IC 50 values of PGPR, GPY and HGGR were shown to be 24.84 ± 0.02, 30.44 ± 0.33 and 24.89 ± 0.19 mM, respectively. Kinetic experiments demonstrated that PGPR and HGGR are mixed-type inhibitors, and GPY is a competitive inhibitor toward XOD with the inhibitory constant (K i) values ranging from 1.09 to 8.98. Our results suggested that MiAMP2 is an important source of bioactive peptides for the management of hyperuricemia.
 
Principal component analysis (a: loading plot, b: score plot) of bioactive properties of coffee brews. TFC total flavonoid content, TPC total phenolic content, TC tannin content, CC caffeine content, Ga, gallic acid, Dihyd 3,4-dihydroxybenzoic acid, Ca catechin, Caf caffeic acid, Syr syringic acid, Ru rutin, Coup-coumaric acid, Fe ferulic acid, Quer quercetin, Cin cinnamic acid, Kaemp kaempferol, C- Colombia, P- Peru, B- Brazil, C control, D decoction, I Infusion, 1 1 min, 3 3 min, 5 5 min
Article
This study was performed to compare the effects of brewing method (decoction and infusion), time (1–5 min), and also origin of coffee beans on antioxidant activity using DPPH, ABTS, FRAP methods, caffeine content and phenolic compounds by HPLC. Principal component analysis was used to determine the effective treatments on bioactive properties. Coffee brews prepared with decoction method contained higher contents of total phenolic, total flavonoid, and total tannin as compared to the infusion method. On the other hand, antioxidant activity of coffee brews by DPPH and ABTS radical methods showed an opposite trend. Similar to antioxidant activity, infusion method was better to obtain higher amounts of catechin, caffeic acid and quercetin in coffee brews. The brewing method did not cause a significant difference in caffeine and rutin contents. Brewing time had major effects on several bioactive compounds, and their amounts showed an increase after extending the time of brewing.
 
Major phenolic compounds present in cereals and millets
Article
Whole grain consumption has been linked to enhanced health benefits, in which phenolic compounds play a vital role. Apart from this, phenolic compounds in cereal grains also make a significant contribution in browning and off-flavor generation of cereal products during storage. This review discusses the nutritional role of phenolic compounds present in major grains, along with their storage stability and how these compounds affect the lipid oxidation of cereal flour during its period of storage. This study also highlights how different processing treatments, i.e., thermal, mechanical, bioprocessing, etc. in the grain/flour affect the phenolic composition and antioxidant properties of the stored products, together with the influence of various treatments on the prevention of browning of flour products. This study will aid the industries and researchers working in the field of nutritional improvement, to select and optimize the treatments with enhanced health benefits, along with an emphasis on consumer's sensory satisfaction.
 
Article
The aim of the present work was to verify in winemaking the anti-stress efficacy due to the integration of the grape must with two protectants: pomegranate albedo and pomegranate arils; these substances had displayed in vitro anti-stress effects. The effect of pomegranate supplementation on stress tolerance of five strains of Saccharomyces cerevisiae , one wild type and four descendants, against fermentation in grape must with high sugar content (30°brix) and high acidity (pH 3.00) was studied. So, micro-winemaking trials were carried out using grape must, as it is or supplemented at 2% with pomegranate albedo or with pomegranate arils, inoculated in duplicate with the yeast strains. At the end of winemaking, ethanol and acetic acid content, colour intensity, total phenolic content, and total antioxidant activity by DPPH and ABTS assays were analysed. The results shown the possibility to use pomegranate as protective agent in winemaking with high sugar content and high acidity giving wines in which the fermentable sugars will be fermented with acceptable acetic acid content, very high colour intensity values, very high total phenolic content, and very high antioxidant activity, expressed as DPPH and ABTS values.
 
Article
Coffee is one of the mostly consumed beverages worldwide. Roasting of coffee is an important process causing many changes in the quality and sensory characteristics of coffee beans. The objective of this study was the determination of the effect of roasting on the physicochemical and sensory properties and comparison of six coffee varieties, namely Brazil Santos, Brazil Rio Minas, Mexico Finca Muxbal, Guatemala Shb Ep, Ethiopia Djimmah, and India Robusta. Coffee beans were subjected to heat treatment at air temperatures up to 270 °C for up to 20–27 min, depending on the coffee variety and the desirable roasting degree. During the whole process, various physicochemical properties (mass, volume, density, color) and sorption isotherms of coffee beans were measured. For sensory evaluation, arabian and espresso beverages were prepared. Color of coffee beans darkened with increasing time and temperature during roasting, while volume increased. Total mass loss was also observed. Sorption isotherms followed type III, except for the variety India Robusta and the raw samples that followed type II. Sensory characteristics were distinctly different for each of the studied varieties. In arabian coffee drinks the color of cream was darker compared to espresso drinks and presented less acid and sour taste. Concerning texture, the body was positively evaluated both in arabian and espresso drinks. Graphical abstract
 
Article
The constant increase in the demand for safe and high-quality food has generated the need to develop efficient methods to evaluate food composition, vitamin C being one of the main quality indicators. However, its heterogeneity and susceptibility to degradation makes the analysis of vitamin C difficult by conventional techniques, but as a result of technological advances, vibrational spectroscopy techniques have been developed that are more efficient, economical, fast, and non-destructive. This review focuses on main findings on the evaluation of vitamin C in foods by using vibrational spectroscopic techniques. First, the fundamentals of ultraviolet–visible, infrared and Raman spectroscopy are detailed. Also, chemometric methods, whose use is essential for a correct processing and evaluation of the spectral information, are described. The use and importance of vibrational spectroscopy in the evaluation of vitamin C through qualitative characterization and quantitative analysis is reported. Finally, some limitations of the techniques and potential solutions are described, as well as future trends related to the utilization of vibrational spectroscopic techniques.
 
Article
This review provides an overview on the production and analysis techniques of antioxidative peptides from food proteins. Regarding the production of antioxidative peptides, interlinked factors must be considered. Depending on the protein substrate, different peptidases or peptidase systems containing multiple enzymes as well as a specific production process must be chosen. The antioxidative peptides might be produced in a batch process including multiple pre- and post-treatments, besides the hydrolyses with peptidases itself. As an alternative, the potential of continuous production systems is discussed in this review. Furthermore, robust analyses tools are needed to gain control of the process and final product properties. With no standardized methodology available for antioxidative peptide evaluation, pros and cons of various strategies for peptide separation and antioxidative measurement are discussed in this review. Therefore, this review provides a roadmap for antioxidative peptide generation from various sources for research and development as well as for potential industrial use.
 
Top-cited authors
Antonio Piga
  • Università degli Studi di Sassari
Alessandra Del Caro
  • Università degli Studi di Sassari
Koen Dewettinck
  • Ghent University
Marco Poiana
  • Mediterranean University of Reggio Calabria
Marek Siwulski
  • Poznań University of Life Sciences