Preliminary Phytochemical Screening and Antioxidant Activity of Commercial Moringa oleifera Food Supplements.

Moringa oleifera has been reported to possess a high number of bioactive compounds; hence, several food supplements are commercially available based on it. This work aimed to analyze the phytochemical composition and antioxidant activity of commercial food supplements. The phenolic composition of methanolic extracts was determined by using high-performance liquid chromatography with diode-array and electrospray ionization mass spectrometric detection (HPLC-DAD-ESI-MSn), and the antioxidant activity was assessed by ABTS·+ and DPPH assays. Thirty-three compounds were identified, and all the main compounds were quantified, observing that the main contribution to the phenolic profile was due to kaempferol and quercetin glucosides. The antioxidant activity in both assays agreed with the phenolic content: the higher the phenolic levels, the higher the antioxidant activity. The obtained results were compared with those previously published regarding Moringa oleifera leaves to establish the potential benefits of food supplement consumption in the diet.

Phenolic Analysis and In Vitro Biological Activity of Red Wine, Pomace and Grape Seeds Oil Derived from Vitis vinifera L. cv. Montepulciano d'Abruzzo.

Grape pomace is commonly considered a waste product of monovarietal red wine production. Methods: HPLC-DAD analysis was performed to determine the polyphenol and flavonoid contents of all the extracts obtained from Montepulciano d'Abruzzo red wine and grape skins whereas, GC-MS was applied to the determination of fatty acid composition in grape seeds oil. Biological characterization involves antioxidant and antimicrobial assays for all the extracts and seeds oil; Their ability to inhibit α-glucosidase, α-amylase, α-tyrosinase, and ChE enzymes was also detected, together with anti-inflammatory activity on wine, grape skin extracts, and seeds oil by lipoxygenase (5-LOX) and LPS-stimulated macrophage release assays. Data indicate significative polyphenols content (199.31 ± 7.21 mgGAE/g), antioxidant (CUPRAC assay (1036.98 mgTE/g)), enzymatic inhibition (α-tyrosinase: 151.30 ± 1.20 mgKAE/g) and anti-inflammatory activities for wine-organic extract 2, while the antimicrobial activity of grape skin decoction is higher than those reported by wine extracts on three bacterial strains. Interestingly only dealcoholized wine and wine-aqueous extract exerts inhibitory effects on α-glucosidase (20.62 ± 0.23 mmolACAE/g and 19.81 ± 0.03 mmolACAE/g, respectively), while seeds oil is rich in oleic and linoleic acids. These results confirm the strong antioxidant properties of Montepulciano d'Abruzzo grape pomace, suggesting the potential use of this waste product as functional food supplements in the human diet and in cosmeceutics.

Integration of in vitro and in silico perspectives to explain chemical characterization, biological potential and anticancer effects of Hypericum salsugineum: A pharmacologically active source for functional drug formulations.

The genus Hypericum is one of the most popular genera in both traditional medicine and scientific platform. This study is designed to provide conceptual insights on the biological potential and chemical characterization of H. salsugineum, which is endemic to Turkey. The qualitative and quantitative phenolic content of the extracts was characterized by HPLC-ESI-MSn. Biological efficiency was investigated by enzyme inhibitory assays (cholinesterases, tyrosinase, amylase, and glucosidase) and anti-cancer efficacy tests (anti-proliferative activities with the iCELLigence technology, colony formation and wound healing scratch assays). Phenolic acids (3-O-caffeoylquinic, 5-O-caffeoylquinic, and 4-O-caffeoylquinic acids) were the predominant group in the studied extracts, although several flavonoids were also detected and quantified. The extracts exhibited good inhibitory effects on tyrosinase and glucosidase, while they had weak ability against cholinesterases and amylase. Computational studies were also performed to explain the interactions between the major phenolics and these enzymes. The extracts displayed significant anti-cancer effects on breast carcinoma cell lines. Our findings suggest that Hypericum salsugineum could be valued as a potential source of biologically-active compounds for designing novel products.

Polyphenolic profile and antioxidant activities of Madeiran elderberry (Sambucus lanceolata) as affected by simulated in vitro digestion.

The aims of this study were twofold: a) to provide a detailed report on the phenolic composition and antioxidant activity of fresh berries and leaves of Sambucus lanceolata (Madeiran elderberry); b) to study the effects caused by a simulated in vitro digestion on the composition and antioxidant activity of the berries and leaves. Seventy-seven phytochemicals, mainly polyphenols, were identified in the methanol extracts of fresh berries and leaves, with the content of polyphenols higher in berries (27.2mg·g-1 dry extract, DE) than in leaves (25.9mg·g-1 DE). Anthocyanins were dominant in berries, while hydroxycinnamic acids (HCAs) and flavonols were abundant in leaves. Higher antioxidant activities were found in leaves than in berries, using several in vitro assays. After the simulated in vitro digestion, the levels of polyphenols were significantly reduced, in particular those of berries (81.8% decrease). Anthocyanins were the most affected compounds during the simulated digestion. However, despite the significant loss of phenolic compounds during digestion, methanol extracts of digested berries and leaves were still able to scavenge free-radicals. Hence, the consumption of leaves and/or berries of S. lanceolata may help prevent oxidative stress.

Analysis of Bisphenol A in milk by using a multicommuted fluorimetric sensor.

Bisphenol A (BPA) is a polyphenol widely used in industry as an intermediate in the production of polycarbonate plastics and epoxy resins, which are applied to produce plastic food containers, inner surface coating of food and beverage cans. Hence, BPA can migrate from these containers and cans with epoxy coating into foods. It is dangerous taking into account that BPA is considered as a potential endocrine disruptor, which mimics the action of the hormone estrogen. The method here proposed for the determination of BPA involves the implementation of solid-phase spectroscopy (SPS) in an automatic flow system. With this purpose, the measurement of the native fluorescence of BPA, retained on C(18) silica gel together with the implementation of multicommutation have been employed for its determination in different types of milk. The analytical measurements were made at 271/305nm (λ(ex)/λ(em)) obtaining a detection limit (LOD) of 0.06ngmL(-1). The pre-cleaning procedure and the posterior extraction with C(18) applied to the samples allowed the removal of proteins and the extraction of BPA from the matrix, respectively. The method showed an RSD lower than 6.0% (n=10). BPA was determined in powdered milk, infant formula and pure liquid milk samples, being found in five samples at levels lower than the maximum residue limit (MRL) established by the European Union. In addition, a recovery study has been carried out where values close to 100% were observed in all cases, so demonstrating that the proposed analytical method fulfills the requirements for its application in quality control analyses.

Indirect determination of aflatoxin B1 in beer via a multi-commuted optical sensor.

This paper reports the determination of aflatoxin B1 (AFB1), one of the most carcinogenic substances known. A multi-commuted flow injection-solid phase spectroscopy (FI-SPS) system combined with photochemically induced fluorescence (PIF) was developed, for the first time, for its quantitative determination. A strongly fluorescent degradation product was obtained on-line by irradiation with ultraviolet light. The determination was carried out by measuring the fluorescence intensity of the photo-product at 353/424 (λ (ex)/λ (em)), once retained on C18 silica-gel filling the flow-cell. A linear dynamic range of 0.09-12 µg l⁻¹, detection limit as sensitive as 29 ng l⁻¹ and a relative standard deviation (RSD) of 1.4% were obtained. The method proposed was satisfactorily applied to the determination of AFB1 in different types of beer (normal and non-alcoholic). Hydrophobic compounds were eliminated from beer samples and AFB1 was extracted with acetonitrile by solid-phase extraction on C18 sorbent. Recoveries of the target compound from spiked beers were between 94 and 106%. The results obtained in the analysis of real samples are in good agreement with those provided by a reference chromatographic method.

A novel multicommuted fluorimetric optosensor for determination of resveratrol in beer.

Resveratrol (3,5,4'-trihydroxystilbene) is a phytoalexin that plays a central role in the human diet because of its antioxidant, anticarcinogenic and antimutagenic properties. This paper shows the development of a multicommuted optosensing device for the determination of resveratrol in beer. The method is based on the measurement of the fluorescence (277/382 nm, λ(ex)/λ(em)) of the photoproduct on-line generated by UV-irradiation of resveratrol. The fluorescent photoproduct is monitored once it is retained on a solid support (Sephadex QAE A-25) in the detection area, which improves both sensitivity and selectivity. The sample was delipidated with toluene and cyclohexane and resveratrol was extracted by solid-phase extraction (SPE) on C(18) cartridges, using methanol as eluent. This pre-treatment allowed recovering about an 82% resveratrol and removing its 3-O-ß-d-glycoside (piceid) and other interfering substances present in beer. The method provides a detection limit (DL) of 1.0 ng mL(-1) and a linear dynamic range (LDR) of 3.3-100 ng mL(-1). It was satisfactorily applied to the determination of resveratrol in top- and bottom-fermented beers by standard addition calibration. Resveratrol concentrations in the analysed samples varied from 4.1 to 14.1 ng mL(-1). This is the first proposed spectroscopic method for determination of resveratrol in beer.

Automatic optosensing device based on photo-induced fluorescence for determination of piceid in cocoa-containing products.

Piceid (3,4',5-trihydroxystilbene-3-ß-D: -glucoside) is a stilbene which occurs naturally in various families of plants and has been shown to protect lipoproteins from oxidative damage and to have cancer chemopreventive activity. This paper deals with the determination of piceid in cocoa-containing products by using photo-induced fluorescence and the aid of a multicommutated continuous-flow assembly which was provided with an on-line photoreactor. A strongly fluorescent photoproduct is generated from piceid when it is irradiated under UV light for 30 s, which is retained on Sephadex QAE A-25 and directly monitored on this active solid support at 257/382 nm (λ (exc)/λ (em), respectively). The pre-concentration of the photoproduct of piceid on the solid support greatly improves both sensitivity and selectivity. The influence of different experimental parameters, both chemical (pH, ionic strength) and hydrodynamic (irradiation time, flow rate, photoreactor length, sampling time), was tested. The sample pre-treatment included delipidation with toluene and cyclohexane, stilbene extraction with ethanol/water (80:20, v/v) and clean-up by solid-phase extraction on C(18) cartridges and methanol/water (40:20, v/v) as eluting solution. This procedure allowed the elimination of the aglycon of piceid, resveratrol and other potential interfering species and a recovery of about a 90% piceid. The method was applied to the analysis of piceid in cocoa powder, dark chocolate and milk chocolate. The quantification limits were 1.4, 1.1 and 0.09 mg kg(-1), respectively. Relative standard deviations ranged from 1.8% to 3.1%. This is the first reported non-chromatographic method for determination of piceid in these foods.

Determination of pesticides in washing waters of olive processing by gas chromatography-tandem mass spectrometry.

A simple and rapid SPE-GC method for the determination of 30 organochlorine, organophosphorus, and organonitrogen pesticides at ng/L levels in washing water of olive processing has been developed. Twenty-nine samples of water were collected directly in the inlet and outlet of the washing machines of three olive mills at various locations in Spain. Preconcentration and clean-up were performed by elution of the pesticides from a C18 SPE cartridge using dichloromethane. The target compounds were determined in the final extract by GC-MS/MS. The most frequently encountered pesticide residues were terbuthylazine, simazine, and diuron. In some of the water samples, coming from the inlet of the washing machines, terbuthylazine and diuron concentrations were above the maximum residue limit.

Simplified pesticide multiresidue analysis in virgin olive oil by gas chromatography with thermoionic specific, electron-capture and mass spectrometric detection.

In the present work, an analytical multiresidue method has been developed for the analysis of 32 organochlorine, organophosphorus and organonitrogen pesticides at microg kg(-1) levels in virgin olive oil. The method consists of the extraction of the pesticides with acetonitrile saturated in n-hexane followed by a clean-up process based on gel permeation chromatography (GPC) with ethyl acetate-ciclohexane (1:1) as mobile phase to separate the low-molecular mass pesticides from the high-molecular mass fat constituents of the oil. The target compounds were determined in the final extract by gas chromatography (GC) using thermoionic specific (TSD) and electron-capture (ECD) detection. In the case of positive samples, the amounts found were confirmed by GC-MS/MS, being the results in good agreement. Recoveries and RSDs (n = 10) values were 91-124% and 1-8% (GC-ECD), 82-100% and 9-20% (GC-TSD), and 89-105% and 4-14% (GC-MS/MS), respectively. The three proposed methods were applied to samples collected directly in two olive mills located in the Jaén province (Spain). Specifically, 24 samples of virgin olive oil were collected. The most frequently pesticide residues found were the herbicides terbuthylazine and diuron and endosulfan sulfate, a degradation product of the insecticide endosulfan. The herbicide concentration was higher in those oil samples obtained from olives which were collected from the ground after they had fallen down than in those oil samples from olives harvested directly from the tree. The GC-MS/MS developed method was also applied to the analysis of an olive oil sample from a proficiency test spiked with organochlorine pesticides and all the values obtained were within the specified "satisfactory" range.