348 research outputs found
Physico-chemical properties and chemical analysis of wildflower honey before and after the addition of Spirulina (Arthrospira platensis)
Full text linkIn this study, in order to verify the effects due to the addition of spirulina (Arthrospira
platensis) in a food product, a wildflower honey was analyzed in terms of chemical composition,
physicochemical properties and antioxidant activity before and after the addition of the spirulina. HSSPME/
GC–MS and HPLC/UV were applied to carry out the chemical analyses. The obtained results
demonstrated that the volatile profile and also the sugar content were significantly influenced by the
addition of spirulina, showing significant qualitative and quantitative differences compared to honey
without spirulina. The increase in HMF in honey added with spirulina was significant, demonstrating
that its presence could accelerate the Maillard reaction. Electrical conductivity measured by using a
conductometer was also increased while the moisture content was reduced in honey enriched with
spirulina. Instead, the pH value was similar between the two samples. On the other hand, honey
fortification with spirulina determined a significant increase of 12.5% in the total phenolic content
(TPC), and a 56.25% increase in protein content. Further, the total antioxidant capacity (TAC) was
also evaluated and a significant increase was determined as a result of the addition of spirulina. In
conclusion, honey enriched with A. platensis was found to be characterized by a high pool of bioactive
metabolites as well as significant changes in almost all the measurements performed
SPME-GC-MS and PTR-ToF-MS Techniques for the Profiling of the Metabolomic Pattern of VOCs and GC-MS for the Determination of the Cannabinoid Content of Three Cultivars of <i>Cannabis sativa</i> L. Pollen
No full textConsidering the large number of volatile molecules that characterize Cannabis sativa L., adequate investigation supported by the application of robust and effective analytical methods is essential to better understand the impact of these low- and medium-molecular-weight molecules on the entire phytocomplex. This work aimed to characterize the volatile fraction of the chemical profile of three different cultivars of Cannabis sativa L. pollen, grown in Italy, which were thoroughly investigated by the application of two complementary techniques: SPME-GC-MS and PTR-ToF-MS. Furthermore, in order to provide more information on the chemical profile of the matrices under study, the cannabinoid content of the hexane extracts was also measured by GC-MS. Until now, no similar study, in terms of survey techniques applied, has been performed on C. sativa pollen. The obtained results showed a high content of volatile molecules, which differentiated the three matrices. The data relating to the content of cannabinoids were also interesting as they showed that one of the three cultivars was richer than the others. Finally, an in-depth statistical survey was performed to better compare the investigated samples and identify the molecules that most contribute to differentiating them. The findings of this study may be useful for integrating the compositional information on C. sativa L
Does the Harvest Type Affect Olive Health? Influence of the Harvesting System and Storage Time on the Chemical, Volatile and Sensory Qualities of Extra Virgin Olive Oils
Full text linkWith the aim of investigating the effect of bruising and its development during the postharvest time, olive fruits (Frantoio and Moraiolo), manually and mechanically harvested, were stored in climatic chambers at two different temperatures (5 °C and 18 °C) for five days. Visual observations highlighted changes in the olive peel with discoloration in the damaged areas and tissue bruising. Olive fruit polyphenols, volatile organic compounds (VOCs) and other oil quality parameters (phenolic content, free acidity and peroxide index) and sensory assessment were evaluated. Analyses were carried out on fruits and experimental extra virgin oils at harvesting and after 5 days of fruit storage. The results highlight that low-temperature storage (5 °C for 5 days) may contribute to the maintenance of high olive oil quality, and the quality of olives stored at room temperature drastically decreases after 5 days of storage. Moreover, mechanical harvesting, compared to manual harvesting, does not seem to affect the final oil quality, at least at harvesting, but seems to determine differences in the long-term storage period. Finally, the samples stored at 18 °C showed a quality deterioration with the development of sensorial defects
Exploring the Metabolome and Antimicrobial Properties of Capsicum annuum L. (Baklouti and Paprika) Dried Powders from Tunisia
Full text linkIn this study, for the first time, the volatile fraction from two domesticated Capsicum annuum accessions (“Paprika” and “Baklouti”) collected in Tunisia was investigated by two complementary analytical techniques, such as Solid-Phase Microextraction–Gas Chromatography/Mass Spectrometry (SPME-GC/MS) and Proton Transfer Reaction–Time-of-Flight–Mass Spectrometry (PTR-ToF-MS). The obtained results highlighted the presence of a high number of Volatile Organic Compounds (VOCs), including monoterpene and sesquiterpene compounds with α-curcumene, I-zingiberene, β-bisabolene and β-sesquiphellandrene as the major components. In addition, GC/MS was used to investigate the non-volatile chemical composition of the dried powders and their extracts, which were found to be rich in sulfur compounds, fatty acids and sugars. Eleven bacterial strains were chosen to assess the antimicrobial effectiveness of the extracts. The results showed that the extracts exhibited strain-dependent behavior, and the type strains displayed a greater susceptibility to the treatments, if compared to the wild strains, and, in particular, showed the best antimicrobial activity against Gram-positive bacteria, such as Listeria monocytogenes and Staphylococcus aureus
Volatile organic compounds in truffle (Tuber magnatum Pico): Comparison of samples from different regions of Italy and from different seasons
No full textIn this paper volatile organic compounds (VOCs) from Tuber magnatum fruiting bodies were analyzed using a PTR-TOF-MS instrument. The aim was to characterize the VOC's profile of the fruiting bodies and identify if any VOCs were specific to a season and geographical areas. Multiple factorial analysis (MFA) was carried out on the signals obtained by MS. Experiments using ITS region sequencing proved that the T. magnatum life cycle includes the formation of fruiting bodies at two different times of the year. The VOCs profiles diverge when different seasonal and geographical productions are considered. Using PTR-TOF-MS, compounds present at levels as low pptv were detected. This made it possible to determine both the origin of fruiting bodies (Alba and San Miniato) and the two biological phases of fruiting bodies formation in San Miniato truffles
Identification of volatile molecules and bioactivity of Gruyt craft beer enriched with citrus aurantium var. dulcis l. essential oil
No full textIn this work, for the first time, a gruyt beer and the same one after the addition of
Citrus aurantium essential oil (AEO), were investigated to determine the composition of the volatile
fraction. The applied analytical techniques, such as Head Space/Solid Phase Microextraction-Gas
Chromatography-Mass Spectrometry (HS/SPME-GC-MS) and Proton Transfer Reaction-Time of
Flight-Mass Spectrometer (PTR-ToF-MS), allowed us to identify the content of volatile organic
compounds (VOCs). From the comparison between the two beer samples, it showed that the one after
the addition of AEO was particularly richened in limonene and a series of minor terpene compounds.
AEO was also characterized by GC/MS analysis and the results showed that limonene reached 95%.
Confocal microscopy was used to look at riboflavin autofluorescence in yeast cells. It was found
that beer with AEO had twice as much fluorescence intensity as the control. A spectrophotometric
analysis of total polyphenols, tannins, and flavonoids, and a bioactivity screening, including 2,2-
diphenyl-1-picrylhydrazyl (DPPH) and 2,2′
-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid) (ABTS)
radical scavenger, chelating, reducing, antiglycative ones, were also carried out. Moreover, the
tolerability of the tested samples in human H69 cholangiocytes and the cytoprotection towards the tertbutyl hydroperoxide (tBOOH)-induced oxidative damage were evaluated. Under our experimental
conditions, the beers were found to be able to scavenge DPPH and ABTS radicals and chelate iron
ions, despite weak antiglycative and reducing properties. The tested samples did not affect the
viability of H69 cholangiocytes up to the highest concentrations; moreover, no signs of cytoprotection
against the damage induced by tBOOH were highlighted. Adding AEO to beer resulted in a moderate
enhancement of its DPPH scavenging and chelating abilities, without improvements in the other
assays. Conversely, AEO and its major compound limonene were ineffective when assessed at the
concentrations added to beer. This evidence suggests that the addition of AEO may enhance the
organoleptic features of the beer and slightly potentiate some of its bioactivities
Examination of Volatile Signatures of Fusarium Bulb Rot in Garlic Using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry and Solid-Phase Microextraction Gas Chromatography/Mass Spectrometry
No full textFusarium bulb rot, caused by Fusarium proliferatum, is a worldwide disease of garlic, both in the open field and during storage. Early diagnosis of the disease during storage is difficult due to the morphology of the bulbs and cloves. Volatile organic compounds (VOCs) are secondary metabolites produced by several microorganisms, including phytopathogenic fungi and bacteria. In recent years, the development of several techniques for the detection and characterization of VOCs has prompted their use, among others, as a diagnostic tool for the early and non-destructive analysis of many diseases of species of agricultural interest. In this paper, proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and solid-phase microextraction gas chromatography/mass spectrometry (SPME-GC/MS) were successfully utilized to characterize the volatolome of commercial garlic cloves, artificially and naturally infected with F. proliferatum, for the early discrimination between diseased and healthy ones. A partial least squares discriminant analysis (PLSDA) and a principal component analysis (PCA) allowed for the separation of infected and healthy cloves and the identification of specific VOCs produced by the fungus during the infection. The results obtained in this work could be utilized for the development of simpler, more economical, and more portable devices for the early detection of infected garlic bulbs during storage
Metabolomic Approach Based on Analytical Techniques for the Detection of Secondary Metabolites from Humulus lupulus L. Dried Leaves
No full textCurrently, the leaves of the hop plant (Humulus lupulus L.) are an unexploited and still
little-investigated agricultural by-product. In our study, with the aim of exploring the metabolome of
dried hop leaves (Chinook cultivar), a metabolomic approach was applied using multiple analytical
tools such as SPME/GC–MS, GC–MS, PTR-ToF-MS, and NMR to identify the secondary metabolites.
The obtained results showed the presence of a high number of components belonging to different
chemical classes. In fact, thanks to the multi-methodological approach, volatile organic compounds
(VOCs) with low molecular weight, terpenic compounds, fatty acids, sugars, amino acids, organic
acids, and alcohols have been detected and identified. Among the revealed terpenes in the untreated
matrix, the sesquiterpenes -humulene, b-caryophyllene, and a-copaene were the most abundant.
Among the saturated and unsaturated fatty acids, palmitic and linolenic acids, respectively, were
those with the highest relative percentages. Particularly relevant was the sugar content, where sucrose
was the main exponent while glutamate and asparagine were the principal detected amino acids.
Conversely, alcohols and organic acids were the least abundant compound classes, and xanthohumol
was also identified in the methanolic extract
Sensory, spectrometric (PTR–ToF–MS) and chemometric analyses to distinguish extra virgin from virgin olive oils
No full textOlive oil samples were obtained from six cultivars grown in different environments, and graded by chemical analyses as extra virgin (EVOOs). These were evaluated for flavors and off-flavors, and relative VOCs spectrum as determined by PTR–ToF–MS. A hierarchical clustering of Panel test data separated olive oil in three groups, one including the samples with perceived off-flavor (VOOs), regardless of cultivar and environment. The Pearson’s correlation coefficients between the mass data from PTR–ToF–MS and the sensory characteristics perceived by the Panel test were determined. A mass-to-sensory attributes correlation index was calculated. A colorcoded card was built up based on the intensities (ncps) of five selected protonated mass data that was able to distinguish EVOOs from VOOs olive oil samples
Nashi or Williams pear fruits? Use of volatile organic compounds, physicochemical parameters, and sensory evaluation to understand the consumer’s preference
No full textRipen “ready-to-eat” fruits of “Williams” and of two Nashi cultivars (“Hosui” and “Ya Li”), present contemporarily on the stores, were evaluated by physicochemical parameters (shape, skin color, firmness, total soluble solids, titratable acidity), volatile organic compounds (VOCs) emission, measured with a proton transfer reaction-time of flight-mass spectrometer (PTR–ToF–MS), either on whole and cube fruits, and sensory evaluation (panel test and consumer’s liking). The data were analyzed by ANOVA, LSD test, hierarchical clustering, PLS-DA, and CCOA. The highest differences for the physicochemical parameters were observed between Williams and Nashi, as Williams differentiated for sugar content and Hosui for firmness. By VOCs spectral analyses, it was observed that whole and cube “Williams” fruits had the highest number and amount of compounds, followed by “Ya Li;” “Hosui” was characterized by a few signals with low intensities. Fruits of each cultivar showed specific VOCs that could be used as markers for discrimination purposes. In “Williams” pears, the presence and amount of defined masses resulted linked to fruitiness and aroma perceived by the consumer. The higher sugar content and the typical pear aroma perceived by the panelists, emitted by “Williams,” could have influenced the consumer’s liking. The tasters appreciated “Hosui” for firmness, and “Ya Li” for visual, even if they resulted lower in sugar and flavor intensity. In the opinion of the respondents to the consumer test, “Williams” resulted the most appreciated both for the average scores of the acceptability and as percentage of responses at a level >5 of a nine-point hedonic scale
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