Geographical authentication of virgin olive oil by GC-MS sesquiterpene hydrocarbon fingerprint: Verifying EU and single country label-declaration.

According to the last report from the European Union (EU) Food Fraud Network, olive oil tops the list of the most notified products. Current EU regulation states geographical origin as mandatory for virgin olive oils, even though an official analytical method is still lacking. Verifying the compliance of label-declared EU oils should be addressed with the highest priority level. Hence, the present work tackles this issue by developing a classification model (PLS-DA) based on the sesquiterpene hydrocarbon fingerprint of 400 samples obtained by HS-SPME-GC-MS to discriminate between EU and non-EU olive oils, obtaining an 89.6% of correct classification for the external validation (three iterations), with a sensitivity of 0.81 and a specificity of 0.95. Subsequently, multi-class discrimination models for EU and non-EU countries were developed and externally validated (with three different validation sets) with successful results (average of 92.2% of correct classification for EU and 96.0% for non-EU countries).

Development and validation of a Fast gas chromatography/mass spectrometry method for the determination of cannabinoids in Cannabis sativa L.

A routine method for determining cannabinoids in Cannabis sativa L. inflorescence, based on Fast gas chromatography coupled to mass spectrometry (Fast GC/MS), was developed and validated. To avoid the decarboxylation of carboxyl group of cannabinoids, different derivatization approaches, i.e. silylation and esterification (diazomethane-mediated), reagents and solvents (pyridine or ethyl acetate), were tested. The methylation significantly increased the signal-to-noise ratio of all carboxylic cannabinoids, except for cannabigerolic acid (CBGA). Since diazomethane is not commercially available, is considered a hazardous reactive and requires 1-day synthesis by specialized chemical staff, silylation was used along the whole validation of a routine method. The method gave a fast (total analysis time < 7.0 min) and satisfactory resolution (R > 1.1), with a good repeatability (intraday < 8.38%; interday < 11.10%) and sensitivity (LOD < 11.20 ng/mL). The Fast GC/MS method suitability for detection of cannabinoids in hemp inflorescences, was tested; a good repeatability (intraday < 9.80%; interday < 8.63%), sensitivity (LOD < 58.89 ng/mg) and robustness (<9.52%) was also obtained. In the analyzed samples, the main cannabinoid was cannabidiolic acid (CBDA, 5.19 ± 0.58 g/100 g), followed by cannabidiol (CBD, 1.56 ± 0.03 g/100 g) and CBGA (0.83 g/100 g). Δ9-tetrahydrocannabivarine (THCV) was present at trace level. Therefore, the developed routine Fast GC/MS method could be a valid alternative for a fast, robust and high sensitive determination of main cannabinoids present in hemp inflorescences.

Detection of Fumonisins in Fresh and Dehydrated Commercial Garlic.

An epidemic fungal disease caused by Fusarium proliferatum, responsible for fumonisin production (FB1, FB2, and FB3), has been reported in the main garlic-producing countries in recent years. Fumonisins are a group of structurally related toxic metabolites produced by this pathogen. The aim of this work was to establish an enzyme-linked immunosorbent assay (ELISA) procedure, mostly applied to cereals, that is suitable for fumonisin detection in garlic and compare these results to those obtained by high-performance liquid chromatography (HPLC) and screening of fresh and dehydrated garlic for toxicological risk. The results show good correlation between the two analytical methods. In fresh symptomatic garlic, fumonisin levels were higher in the basal plates than those in the portions with necrotic spots. Among the 56 commercially dehydrated garlic samples screened, three were positive by ELISA test and only one was above the limit of quantitation. The same samples analyzed by HPLC showed the presence of FB1 in trace amounts that was below the limit of quantitation; FB2 and FB3 were absent. The results are reassuring, because no substantial contamination by fumonisins was found in commercial garlic.

How the Addition of Spices and Herbs to Virgin Olive Oil to Produce Flavored Oils Affects Consumer Acceptance.

With the aim to expand the olive oil market to a larger number of consumers who are not familiar with the sensory characteristics of virgin olive oil, the use of novel products known as "flavored olive oils", obtained by adding different kind of spices and aromatic herbs, is spreading in many countries. In order to test consumer acceptability of this type of product, in a country (Tunisia) in which virgin olive oil is regularly consumed, flavored olive oils were prepared by adding aromatic extracts of thyme, oregano, a mix of herbs (used as pizza seasoning), rosemary, and basil to a monovarietal Chemlali virgin olive oil and a consumer test on 206 subjects was performed. Selected quality parameters (free acidity, peroxide number, oxidative stability, specific absorption at K232 nm and K270 nm) were also measured and no significant variations were detected. Slight differences were found concerning the content of minor compounds (chlorophylls, carotenoids and total phenols). On the other hand, notable differences were seen in the profiles of volatile compounds, which appeared to be responsible for the observed variability in consumer acceptance. Although the unflavored oil was more appreciated than the flavored ones, among the latter, thyme flavored olive oil was the most appreciated.

Agricultural by-products with bioactive effects: A multivariate approach to evaluate microbial and physicochemical changes in a fresh pork sausage enriched with phenolic compounds from olive vegetation water.

The use of phenolic compounds derived from agricultural by-products could be considered as an eco-friendly strategy for food preservation. In this study a purified phenol extract from olive vegetation water (PEOVW) was explored as a potential bioactive ingredient for meat products using Italian fresh sausage as food model. The research was developed in two steps: first, an in vitro delineation of the extract antimicrobial activities was performed, then, the PEOVW was tested in the food model to investigate the possible application in food manufacturing. The in vitro tests showed that PEOVW clearly inhibits the growth of food-borne pathogens such as Listeria monocytogenes and Staphylococcus aureus. The major part of Gram-positive strains was inhibited at the low concentrations (0.375-3mg/mL). In the production of raw sausages, two concentrates of PEOVW (L1: 0.075% and L2: 0.15%) were used taking into account both organoleptic traits and the bactericidal effects. A multivariate statistical approach allowed the definition of the microbial and physicochemical changes of sausages during the shelf life (14days). In general, the inclusion of the L2 concentration reduced the growth of several microbial targets, especially Staphylococcus spp. and LABs (2log10CFU/g reduction), while the increasing the growth of yeasts was observed. The reduction of microbial growth could be involved in the reduced lipolysis of raw sausages supplemented with PEOVW as highlighted by the lower amount of diacylglycerols. Moisture and aw had a significant effect on the variability of microbiological features, while food matrix (the sausages' environment) can mask the effects of PEOVW on other targets (e.g. Pseudomonas). Moreover, the molecular identification of the main representative taxa collected during the experimentation allowed the evaluation of the effects of phenols on the selection of bacteria. Genetic data suggested a possible strain selection based on storage time and the addition of phenol compounds especially on LABs and Staphylococcus spp. The modulation effects on lipolysis and the reduction of several microbial targets in a naturally contaminated product indicates that PEOVW may be useful as an ingredient in fresh sausages for improving food safety and quality.

Cardiac and Vascular Synergic Protective Effect of Olea europea L. Leaves and Hibiscus sabdariffa L. Flower Extracts.

This study was aimed at investigating the cardiovascular effects of an Olea europea L. leaf extract (OEE), of a Hibiscus sabdariffa L. flower extract (HSE), and of their 13 : 2 w/w mixture in order to assess their cardiac and vascular activity. Both extracts were fully characterized in their bioactive compounds by HPLC-MS/MS analysis. The study was performed using primary vascular endothelial cells (HUVECs) to investigate the antioxidant and cytoprotective effect of the extracts and their mixture and isolated guinea-pig left and right atria and aorta to evaluate the inotropic and chronotropic activities and vasorelaxant properties. In cultured HUVECs, OEE and HSE reduced intracellular reactive oxygen species formation and improved cell viability, following oxidative stress in dose-dependent manner. OEE and HSE exerted negative inotropic and vasorelaxant effects without any chronotropic property. Interestingly, the mixture exerted higher cytoprotective effects and antioxidant activities. Moreover, the mixture exerted an inotropic effect similar to each single extract, while it revealed an intrinsic negative chronotropic activity different from the single extract; its relaxant activity was higher than that of each single extract. In conclusion OEE and HSE mixture has a good potential for pharmaceutical and nutraceutical application, thanks to the synergistic effects of the single phytochemicals.

Olive oil enriched in lycopene from tomato by-product through a co-milling process.

The aim of this investigation was to produce an olive oil (OO) naturally enriched with antioxidants, recovering carotenoids, in particular lycopene, using an industrial by-product of tomato seeds and skin. For this purpose, a technological process in a low-scale industrial plant to co-mill olives and tomato by-product in de-frosted or freeze-dried forms was applied and studied with respect to control samples. Preliminary results obtained from two different experiments were carried out by 40 kg of cultivar Correggiolo olives and 60 kg of olive blends from different cultivars. In both the experiments, the co-milling showed significant enrichment in carotenoids, especially in lycopene (mean values of 5.4 and 7.2 mg/kg oil from defrosted and freeze-dried by-products, respectively). The experimental results demonstrated the possibility to obtain a new functional food naturally enriched in antioxidant compounds, which might be marketed as "OO dressing enriched in lycopene" or "condiment produced using olives and tomato by-product".

Coffee silverskin: characterization, possible uses, and safety aspects.

The reuse of coffee silverskin (CS), the main waste product of the coffee-roasting industry, could be an alternative to its environmental disposal. However, CS could also contain undesirable compounds, such as ochratoxin A (OTA) and phytosterol oxidation products (POPs). A study on the composition of CS (caffeine, moisture, dietary fibers, carbohydrates, and polyphenol contents) was carried out, with emphasis on OTA and POPs for safety reasons. The lipid fraction showed significant amounts of linoleic acid and phytosterols (7.0 and 12.1% of lipid fraction). Noticeable levels of POPs (114.11 mg/100 g CS) were found, and the phytosterol oxidation rate varied from 27.6 to 48.1%. The OTA content was 18.7-34.4 µg/kg CS, which is about 3 times higher than the European Commission limits for coffee products. The results suggest that CS could be used as a source of cellulose and/or bioactive compounds; however, the contents of POPs and OTA might represent a risk for human safety if intended for human or livestock use.

Tannin analysis of chestnut bark samples (Castanea sativa Mill.) by HPLC-DAD-MS.

In the present investigation, an HPLC-DAD/ESI-MS method for the complete analysis of tannins and other phenolic compounds of different commercial chestnut bark samples was developed. A total of seven compounds (vescalin, castalin, gallic acid, vescalagin, 1-O-galloyl castalagin, castalagin and ellagic acid) were separated and quantified, being 1-O-galloyl castalagin tentatively identified and found for the first time in chestnut bark samples. Thus, this method provided information regarding the composition and quality of chestnut bark samples, which is required since these samples are commercialised due to their biochemical properties as ingredients of food supplements.

Rapid screening of fatty acid alkyl esters in olive oils by time domain reflectometry.

The main aim of the present research is to assess the possibility of quickly screening fatty acid alkyl esters (FAAE) in olive oils using time domain reflectometry (TDR) and partial least-squares (PLS) multivariate statistical analysis. Eighteen virgin olive oil samples with fatty acid alkyl ester contents and fatty acid ethyl ester/methyl ester ratios (FAEE/FAME) ranging from 3 to 100 mg kg(-1) and from 0.3 to 2.6, respectively, were submitted to tests with time domain resolution of 1 ps. The results obtained in test set validation demonstrated that this new and fast analytical approach is able to predict FAME, FAEE, and FAME + FAEE contents with R(2) values of 0.905, 0.923, and 0.927, respectively. Further measurements on mixtures between olive oil and FAAE standards confirmed that the prediction is based on a direct influence of fatty acid alkyl esters on the TDR signal. The suggested technique appeared potentially suitable for monitoring one of the most important quality attribute of the olive oil in the extraction process.

Qualitative and semiquantitative analysis of phenolic compounds in extra virgin olive oils as a function of the ripening degree of olive fruits by different analytical techniques.

Capillary electrophoresis (CE) can be effectively used as a fast screening tool to obtain qualitative and semiquantitative information about simple and complex phenolic compounds of extra virgin olive oil. Three simple phenols (tyrosol, hydroxytyrosol, and vanillic acid), a secoiridoid derivative (deacetoxy oleuropein aglycon), and two lignans (pinoresinol and acetoxypinoresinol) were detected as the main compounds in extra virgin olive oils by high-performance liquid chromatography (HPLC) and capillary zone electrophoresis (CZE). Spectrophotometric indices, radical scavenging activity, and oxidative stability of extra virgin olive oil samples obtained from olives hand-picked at different ripening degrees were statistically correlated with the CZE and HPLC quantification. The concentration of phenols in extra virgin olive oil decreased with ripeness of olive fruits. The high correlations found between CZE and the other analytical results indicate that CE can be applied as a rapid and reliable tool to routinely determine phenolic compounds in extra virgin olive oils.

Effect of olive ripening degree on the oxidative stability and organoleptic properties of cv. Nostrana di Brisighella extra virgin olive oil.

The evaluation of the influence of olive ripening degree on the stability of extra virgin olive oils by the determination of the oxidative stability index, the DPPH(*) radical test, and the quali-quantitative analysis of phenolic compounds, as well as the study of the variation of their sensory profiles, plays a key role in the assessment of the overall olive oil quality. Olives of the cv. Nostrana di Brisighella grown in the north-central Italian region of Emilia-Romagna were picked at four different stages of ripeness and immediately processed in an experimental mill. The polar extracts of oil samples were submitted to spectrophotometric analysis of total phenols and o-diphenols and to liquid chromatographic determination of their quali-quantitative profile (HPLC-DAD/MSD). To attain a complete description of oil samples, fatty acid composition, ultraviolet indices (K(232), K(270), and deltaK), free acidity degree, and peroxide value were also determined according to the European Union methods stated in Regulation 2568/91 (1, Off. J. Eur. Communities 1991, L248, 1-82). Sensory quantitative descriptive analysis (QDA) and triangular tests were performed to establish the influence of olive ripening degree on the resulting oil's organoleptic properties. The evolution of the analytical parameters studied shows that the ripeness stage of Nostrana di Brisighella olives that yields the best oil corresponds to a Jaén index value between 2.5 and 3.5. Oils produced from olives harvested within this time frame present a superior sensory profile accompanied by the highest possible chemical and nutritional properties.

Liquid-liquid and solid-phase extractions of phenols from virgin olive oil and their separation by chromatographic and electrophoretic methods.

The high oxidative stability of virgin olive oil is related to its high monounsaturated/polyunsaturated ratio and to the presence of antioxidant compounds, such as tocopherols and phenols. In this paper, the isolation of phenolic compounds from virgin olive oil, by different methods, was tested and discussed. Particularly liquid-liquid and solid-phase extraction methods were compared, assaying, for the latter, three stationary phases (C8, C18 and Diol) and several elution mixtures. Quantification of phenolic and o-diphenolic substances in the extracts was performed by the traditional Folin-Ciocalteau method and the sodium molybdate reaction, respectively. Furthermore, the quantification of phenolic compounds in the extracts and in a standard mixture was carried out both with diode array and mass spectrometric detection and capillary zone electrophoresis.