Chemical composition, antioxidant activity and
in vitro antimicrobial activity of twelve propolis ethanolic extracts (PEE) from mainland Greece, Greek islands, and east Cyprus were determined. The ...PEE studied contained significant amounts of terpenes and/or flavonoids, anthraquinones – mainly emodin and chrysophanol – and low amounts of phenolic acids and their esters, presenting differences from typical European propolis, and similarities to East Mediterranean propolis. Simple polyphenols and terpenic acids content ranged between 11.9–373.5 and 7.23–286.5
mg/g of PEE, respectively, with anthraquinones representing the 1.3–28.9% of simple polyphenols. Despite differences in composition, the PEE samples exhibited significant antioxidant, antibacterial, and antifungal activities, affecting a wider spectrum of microorganisms than the food grade antibacterial nisin, and presenting lower or no activity against several
Lactobacillus strains. The presence of significant amounts of terpenoids seemed to enhance the antimicrobial activity of PEE. The conclusion, given the non-toxic and natural origin of PEE, is that, besides their potential pharmaceutical and nutraceutical value, propolis balsams from Greece and Cyprus are attractive candidates for use as natural antioxidant and microbicidal additives in food systems, especially those containing lactic acid bacteria.
In the present study we report the crude composition and several bioactive microconstituents content in cooked dry legumes, usually consumed in Mediterranean countries. The legumes studied were broad ...beans, chickpeas, two split peas varieties, two lentils varieties, pinto beans, black-eyed beans, five white beans varieties and white lupines.
Crude protein, crude fibre and energy content ranged from 6.1% to 11.5%, 3.6% to 11.7%, and 103 to 155
kcal/100
g, respectively. Phytosterols concentrations ranged from 13.5 to 53.6
mg/100
g. Tocopherols and squalene were present at 0.26–1.78 and 0.12–1.74
mg/100
g, respectively. Legumes’ lipids were rich in alpha-linolenic acid which comprised 2.5–41.7% of fatty acids. Total phenolic content of the cooked legumes ranged from 11.8 to 25.9
mg gallic acid equivalents/100
g, simple polyphenols ranged between 0.32 and 2.4
mg/100
g and triterpenic acids between 0.34 and 8.5
mg/100
g, with lentils exhibiting the higher values in all cases. Among the simple polyphenols determined, flavonoids – mainly catechins-predominated in lentils and chickpeas, and phenolic acids in the rest of legumes.
Nutritional evaluation concerning the daily intake of macro and micronutrients in relation to the consumption of cooked legumes is discussed.
•PFCs were measured for first time in 10 species of Mediterranean fish/shellfish.•Almost all samples contained detectable levels of PFCs.•The most prominent PFC was PFOS, found in levels up to ...22ngg−1.•PFC concentrations were generally higher after frying or grilling of fish samples.•Human exposure by consumption of these fish species is below limit proposed by EFSA.
Perfluorinated compounds (PFCs) were analyzed in several species of small Mediterranean fish and shellfish, all of which are popular in Greek diet. Analysis was conducted in raw samples and in samples cooked by the two ways preferred in Greek cuisine, i.e. fried in olive oil and grilled. PFCs above the detection limit were found in all raw samples except sardine, mussel and squid. The predominant PFC was PFOS (perfluorooctane sulfonate), the highest concentration of which was measured in picarel (20.4ngg−1 fresh weight). The PFOS values for the rest of the samples were between <LOD and 5.66ngg−1 fw. The concentrations of the detected PFCs were in most cases higher after frying or grilling, this increase being statistically significant. Based on these results, the Tolerable Daily Intake for PFOS and PFOA (perfluorooctanoic acid) through consumption of fish and seafood was well below the values proposed by EFSA.
In recent years, mushrooms have drawn the attention of agro-industries and food-industries as they were considered to be valuable natural sources of health promoting compounds such as β-glucans, ...ergothioneine, and lovastatin. The detection and quantification of such compounds by implementing reliable analytical approaches is of the utmost importance in order to adjust mushrooms' cultivation conditions and maximize the production in different species. Toward this direction, the current study focuses on the comparison of ultraviolet-visible (UV-Vis) spectrometry and liquid chromatography-mass spectrometry (LC-MS) methods (a) by evaluating the content of ergothioneine and lovastatin in mushrooms and (b) by highlighting any possible substrate-based interferences that hinder the accurate determination of these two compounds in order to propose the technique-of-choice for a standardized bioactive compounds monitoring. For this purpose, mushrooms produced by three species (i.e.,
,
, and
) on various cultivation substrates, namely wheat straw (WS), winery (grape marc (GM)), and olive oil (OL) by-products, were examined. Among the two applied techniques, the developed and validated LC-MS methods, exhibiting relatively short analysis time and higher resolution, emerge as the methods-of-choice for detecting ergothioneine and lovastatin in mushrooms. On the contrary, UV-Vis methods were hindered due to co-absorbance of different constituents, resulting in invalid results. Among the studied mushrooms,
contained the highest amount of ergothioneine (822.1 ± 20.6 mg kg
dry sample), whereas
contained the highest amounts of lovastatin (1.39 ± 0.014 mg kg
dry sample). Regarding the effect of different cultivation substrates, mushrooms produced on OL and WS contained the highest amount of ergothioneine, while mushrooms deriving from GM-based substrates contained the highest amount of lovastatin.
Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to monitor the infrared absorption spectra of 79 mushroom samples from 29
,
and
strains cultivated on wheat ...straw, grape marc and/or by-products of the olive industry. The spectroscopic analysis provided a chemical insight into the mushrooms examined, while qualitative and quantitative differences in regions related to proteins, phenolic compounds and polysaccharides were revealed among the species and substrates studied. Moreover, by using advanced chemometrics, correlations of the recorded mushrooms' spectra versus their content in glucans and ergosterol, commonly determined through traditional analytical techniques, allowed the development of models predicting such contents with a good predictive power (
: 0.80-0.84) and accuracy (low root mean square error, low relative error and representative to the predicted compounds spectral regions used for the calibrations). Findings indicate that FTIR spectroscopy could be exploited as a potential process analytical technology tool in the mushroom industry to characterize mushrooms and to assess their content in bioactive compounds.
Previous studies have demonstrated the feasibility of employing by-products of the olive and wine sectors for the production of
mushrooms with enhanced functionalities. In this work we investigated ...the influence of endogenous and exogenous factors on free amino acids (FAAs) profile of
,
and
mushrooms produced on wheat straw (WS), alone or mixed with grape marc (GM), and on by-products of the olive industry (OL). Overall, 22 FAAs were determined in substrates and mushrooms, including all the essential amino acids, the neurotransmitter γ-aminobutyric acid (GABA) and ornithine. On a dry weight (dw) basis, total FAAs ranged from 17.37 mg/g in
to 130.12 mg/g in
samples, with alanine, leucine, glutamine, valine and serine predominating. Similar distribution patterns were followed by the monosodium glutamate (MSG)-like, sweet and bitter FAAs. Significant differences in FAAs level were observed among the species examined and among the cultivation substrates used. Principal Component Analysis (PCA) performed on the entire FAAs profile of six
strains, clearly separated
from
and
, in accordance to their phylogenetic affinity. This is the first report of FAAs in
Greece is ranked third after Spain and Italy in virgin olive oil production. The number of Greek olive cultivars-excluding clonal selections-is greater than 40; however, more than 90% of the acreage ...is cultivated with 20 cultivars, adapted to a wide range of environmental conditions. Greek virgin olive oils, produced mainly with traditional, non-intensive cultivation practices, are mostly of exceptional quality. The benefits of consuming virgin olive oil, originally attributed to its high oleic acid content, are now considered to be the combined result of several nutrient and non-nutrient phytochemicals. The present work summarizes available data regarding natural antioxidants in Greek virgin olive oils (VOO) namely, polar phenolic compounds, tocopherols, squalene, and triterpenic acids. The literature survey indicated gaps in information, which should be filled in the near future so that the intrinsic properties of this major agricultural product of Greece will be substantiated on a solid scientific basis.
Blood lipids and inflammatory markers levels have been associated with the development and progression of atherosclerosis. As the association of inflammatory markers with plasma fatty acids has not ...been extensively evaluated and understood, we sought to investigate the associations between dietary and plasma fatty acids with various inflammation and coagulation markers.
High sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), fibrinogen, and homocysteine were measured in serum of 374 free-living, healthy men and women, randomly selected from the ATTICA's study database. Total plasma fatty acids were determined by gas chromatography. Dietary fatty acids were assessed through a semi-quantitative FFQ.
Multi-adjusted regression analyses revealed that plasma n-3 fatty acids were inversely associated with CRP, IL-6 and TNF-α; plasma n-6 fatty acids were inversely associated with CRP, IL-6 and fibrinogen; monounsaturated fatty acids were inversely associated with CRP and IL-6 (all p-values
<
0.05). Interestingly, the
n-6/
n-3 ratios exhibited the strongest positive correlations with all the markers studied. No associations were observed between dietary fatty acids and the investigated markers.
Measurements of total plasma fatty acids could provide insights into the relationships between diet and atherosclerotic disease. Moreover, the
n-6/
n-3 ratio may constitute a predictor of low-grade inflammation and coagulation.
Accelerated oxidation of vanillin was studied by isothermal and non-isothermal differential scanning calorimetry (DSC) in model solutions. Exothermic peaks of DSC thermograms, due to the oxidation of ...vanillin, were observed. Vanillin oxidation to vanillic acid was confirmed by the detection of vanillic acid in heated vanillin samples using GC–MS. The effect of temperature on vanillin oxidation was studied by conducting DSC experiments with pure vanillin at several different final temperatures and by subsequent determination of vanillin and vanillic acid by GC–MS.
Furthermore, the DPPH
free radical assay was done on DSC-treated samples as well as on mixtures of vanillin–vanillic acid. The radical-scavenging activity of the samples was increased along with the vanillic acid content. Additionally, the antimicrobial activities and the minimum inhibitory concentrations (MIC) of solutions containing vanillin and vanillic acid against
Staphylococcus aureus,
Staphylococcus epidermidis,
Bacillus cereus,
Enterobacter aerogenes,
Escherichia coli and
Yersinia enterocolitica were determined by the agar well-diffusion method. All tested samples exhibited inhibitory activity against all of the bacteria. Yet, the higher the vanillic acid concentration, the lower was the MIC of the samples. It is concluded that the thermal treatment of vanillin-containing food may lead to products with improved antioxidant and antimicrobial properties.
Complex formation is among the mechanisms affecting metal bioaccessibility. Hence, the quantification of organic metal complexation in food items is of interest. Organic ligands in solutions of ...environmental and/or food origin function as buffering agents against small changes in dissolved metal concentrations, being able to maintain free metal ion concentrations below the toxicity threshold. Organic matter in vinegars consists of bioactive compounds, such as polyphenols, Maillard reaction endproducts, etc., capable of complexing metal ions. Furthermore, transition metal ions are considered as micronutrients essential for living organisms exerting a crucial role in metabolic processes. In this study, differential pulse anodic stripping voltammetry (DPASV), a sensitive electrochemical technique considered to be a powerful tool for the study of metal speciation, was applied for the first time in vinegar samples. The concentrations of Cu complexing ligands (
) in 43 vinegars retailed in Greece varied between 0.05 and 52 μM, with the highest median concentration determined in balsamic vinegars (14 μM), compared to that of common vinegars (0.86 μM). In 21% of the vinegar samples examined,
values were exceeded by the corresponding total Cu concentrations, indicating the presence of free Cu ion and/or bound within labile inorganic/organic complexes. Red grape balsamic vinegars exhibited the highest density of Cu ligands per mass unit of organic matter compared to other foodstuffs such as herbal infusions, coffee brews, and beers. Among the 16 metals determined in vinegars, Pb is of particular importance from a toxicological point of view, whereas further investigation is required regarding potential Rb biomagnification.
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