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The objective of this study was to analyze the chemical composition and antioxidant activity of a chickpea husk polyphenol extract (CPE) obtained from Argentinian Kabuli chickpea and to evaluate its antioxidant effect on the chemical quality of sunflower oil. The polyphenol composition of CPE was analyzed by HPLC–ESI‐MS/MS. Antioxidant activity was evaluated by DPPH•, FRAP, ABTS•+, and chelating activity in ferrous ion tests. An accelerated oxidation test in sunflower oil was carried out by applying 0.01, 0.02, and 0.05% p/p CPE and comparing it with BHT (0.02%). Peroxide value, conjugated dienes, and volatile compounds were determined on sunflower oil samples. Twelve polyphenols were identified in the chickpea extract. The CPE showed in vitro antioxidant activity. The lowest doses (0.01% and 0.02%) protected sunflower oil more efficiently against oxidative deterioration than the higher level (0.05%). Chickpea husk extract has a good antioxidant effect on sunflower oil, which helps to preserve the quality properties of this product. [ABSTRACT FROM AUTHOR]

The presence of ecgonine in urine has been proposed as an appropriate marker of cocaine use. Only a few methods have been published for their determination along with cocaine and the rest of its metabolites. Due to their high polarity and consequent solubility in water, these have low recoveries, which is why it is necessary to increase the sensitivity, by the formation of hydrochloric salts or multiderivatization of the analytes or by performing two solid‐phase extractions (SPEs), considerably increasing the time and cost of the analysis. This work describes a fast and fully validated procedure for the simultaneous detection and quantification of ecgonine, ecgonine‐methyl‐ester, benzoylecgonine, nor‐benzoylecgonine, m‐hydroxybenzoylecgonine, cocaethylene, cocaine, norcocaine, and norcocaethylene in human urine (500 μL) using one SPE and simple derivatization. Separation and quantification were achieved by gas chromatography–electron ionization–mass spectrometry (GC–EI–MS) in selected‐ion monitoring mode. Quantification was performed by the addition of deuterated analogs as internal standards. Calibration curves were linear in the adopted ranges, with determination coefficients higher than 0.99. The lower limits of quantification ranged from 2.5 to 10 ng/mL. The intra‐ and inter‐day precision, calculated in terms of relative standard deviation, were 1.2%–14.9% and 1.8%–17.9%, respectively. The accuracy, in terms of relative error, was within a ± 16.4% interval. Extraction efficiency ranged from 84% to 103%. Compared with existing methods, the procedure described herein is fast, since only one SPE is required, and cost‐effective. In addition, this method provides a high recovery for ecgonine, resulting in a better alternative to the previously published methods. Development, optimization, and validation of a one‐step solid‐phase‐extraction (SPE) method with a simple derivatization coupled to gas chromatography–mass spectrometry (GC–MS) to identify and quantify ecgonine, cocaine, and seven other metabolites in human urine samples. This is the first report on the use of one cartridge of SPE, with high recoveries and better limits for quantification of COC and metabolites. The procedure is considered a better alternative to the previously published methods. [ABSTRACT FROM AUTHOR]

Summary: Hake (Merluccius hubbsi) is the most important fish of Argentinean industry. The preservative effects of an oregano essential oil (EO) nanoemulsion (NE) on hake burgers (FB) during 15 days at 4 °C were studied. Fatty acids determined by gas chromatography coupled with mass spectrometry (CG‐MS), volatile compounds determined by solid phase microextraction (SPME) coupled with CG‐MS, total volatile basic nitrogen (TVBN), and microbial count was measured. ANOVA and DCG tests were performed. After 14 days, significant differences were detected among samples (P ≤ 0.05). FB with EO (EO‐FB) and FB with NE containing EO (NEEO‐FB) had the highest content of EPA (eicosapentaenoic acid) (191.82 and 198.42 g kg−1) and DHA (docosahexaenoic acid) (107.97 and 110.87 g kg−1, respectively). Also, NEEO‐FB had the lowest microbial count (7 log CFU g−1). The incorporation of the oregano essential oil into a nanoemulsion improves the preserving activity in hake fish burgers. The incorporation of Oregano EO into a stable NE protected its physical properties. A good interaction of oregano EO‐NE with hake burgers matrix was observed. As a consequence, the oregano EO‐NE preserved PUFAs and reduced the microbial growth of hake burgers. [ABSTRACT FROM AUTHOR]

Rationale: Several opioid analgesics have been related to the prolongation of cardiac repolarization, a condition which can be fatal. In order to establish a correct estimation of the risk/benefit balance of therapeutic doses of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene, it was necessary to develop an analytical method to determinate plasma concentrations of these opioids. Methods: Here we describe a method which incorporates strong alkaline treatment to obtain norpropoxyphene amide followed by a one‐elution step solid‐phase extraction, and without further derivatization. Separation and quantification were achieved by gas chromatography/electron ionization mass spectrometry (GC/EI‐MS) in selected‐ion monitoring mode. Quantification was performed with 500 μL of plasma by the addition of deuterated analogues as internal standards. Results: The proposed method has been validated in the linearity range of 25–1000 ng/mL for all the analytes, with correlation coefficients higher than 0.990. The lower limit of quantification was 25 ng/mL. The intra‐ and inter‐day precision, calculated in terms of relative standard deviation, were 2.0–12.0% and 6.0–15.0%, respectively. The accuracy, in terms of relative error, was within a ± 10% interval. The absolute recovery and extraction efficiency ranged from 81.0 to 111.0% and 81.0 to 105.0%, respectively. Conclusions: A GC/MS method for the rapid and simultaneous determination of meperidine, normeperidine, tramadol, propoxyphene and norpropoxyphene in human plasma was developed, optimized and validated. This procedure was shown to be sensitive and specific using small specimen amounts, suitable for application in routine analysis for forensic purposes and therapeutic monitoring. To our knowledge, this is the first full validation of the simultaneous determination of these opioids and their metabolites in plasma samples. [ABSTRACT FROM AUTHOR]

BACKGROUND:Oxidation products and rancid flavors decrease the sensory quality of food products, making themunacceptable to consumers. Synthetic antioxidants are used in many foods to prevent rancidity, though their safety is questioned. Monoterpenes are obtained from essential oils and many of them have shown antioxidant activity. The objective of this study was to evaluate the stability of sensory and chemical parameters in roasted sunflower seeds supplementedwith carvacrol, thymol and sabinene hydratemonoterpenes. RESULTS: Five samples were prepared: control roasted sunflower seeds (RS-C) and sunflower seeds treated with carvacrol (RS-Car), sabinene hydrate (RS-S), thymol (RS-T) and butylated hydroxytoluene (RS-BHT). The three monoterpenes (carvacrol, sabinene hydrate and thymol) provided protection to this food product, inhibiting the formation of oxidative deterioration compounds such as peroxides and hexanal and undesirable off-flavors such as oxidized and cardboard flavors. Sabinene hydrate had greater effect preventing peroxide formation during storage than the other monoterpenes. CONCLUSION: Carvacrol, sabinene hydrate and thymol could be used as an alternative to synthetic antioxidants for preserving the quality of roasted sunflower seeds. [ABSTRACT FROM AUTHOR]

Phytochemicals have been presumed to possess prophylactic and curative properties in several pathologies, such as arsenic -(As-) induced immunosuppression. Our aim was to discover a lymphoprotective extract from Lantana grisebachii Stuck. (Verbenaceae) (LG). We assessed its bioactivity and chemical composition using cell-based assays. Fractions produced from a hexane extract acutely induced nitrite formation in T-activated cell cultures (P < 0.0001). Water extraction released a fraction lacking nitrite inducing activity in both lymphocyte types. Aqueous LG was found to be safe in proliferated and proliferating cells. The infusion-derived extract presented better antioxidant capacity in proportion to phenolic amount in lymphocytes (infusive LG-1i at 100 μg/mL), which protected them against in vitro As-induced lymphotoxicity (P < 0.0001). This infusive LG phytoextract contained 10.23 ± 0.43 mg/g of phenolics, with 58.46% being flavonoids. Among the phenolics, the only predominant compound was 0.723mg of chlorogenic acid per gram of dry plant, in addition to 10 unknown minor compounds. A fatty acid profile was assessed. It contained one-third of saturated fatty acids, one-third of 9, followed by 6 (~24%) and 3 (~4%), and scarce 7. Summing up, L. grisebachii was a source of bioactive and lymphoprotective compounds, which could counteract As-toxicity. This supports its phytomedical use and research in order to reduce As-related dysfunctions. [ABSTRACT FROM AUTHOR]

Peanut products are susceptible to develop rancid and off-flavours through lipid oxidation. Preservation of these products is one of the problems in the peanut industry. The purpose of this work was to determine the sensory and chemical stability of roasted peanuts ( RP) coated with different edible coatings: carboxymethyl cellulose ( RP- CMC), methyl cellulose ( RP- MC) or whey protein ( RP- WPI) during storage. Sensory attributes and chemical indicators (peroxide and p-anisidine values, and conjugated dienes) of lipid oxidation were measured during storage. Chemical indicator values and intensity ratings of oxidised and cardboard flavours had lower increase in RP- CMC, RP- MC and RP- WPI during storage than in RP, whereas roasted peanutty flavour showed a lower decrease. The stability of RP- CMC is about a double longer with respect to RP. These results indicate that edible coatings preserve the sensory properties of roasted peanuts. Carboxymethyl cellulose exhibited the best protecting effect on this product. [ABSTRACT FROM AUTHOR]

This study reported the chemical composition, phenolic content, antioxidant and anti-lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ-terpinene (32.10%), α-terpinene (15.10%), p-cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α-limonene (76.80%) and 1,8-cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL−1) and DPPH scavenging activity (IC50 0.357 μg mL−1) than Lippia essential oil (7.94 mg gallic acid mL−1 and IC50 0.400 μg mL−1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti-lipase activity (IC50 5.09 and 7.26 μg mL−1). Higher phenolic content in the essential oils was related with higher scavenging and anti-lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products. [ABSTRACT FROM AUTHOR]

Summary The purpose of this work was to determine chemical composition and antioxidant activity of essential oil of different oregano species from Argentina: 'Cordobes', 'Criollo', 'Mendocino' and 'Compacto'. The essential oil composition was determined by gas-liquid chromatography and mass spectrometry. Scavenging activity was analysed by DPPH test. The antioxidant activity of the essential oils was determined by an accelerated oxidation test in canola oil. Thirty-nine compounds were identified in the oregano essential oils. The oregano species showed differences in their chemical composition, radical scavenging activity and antioxidant activity. The main compounds in the studied oregano species were thymol and trans-sabinene hydrate followed by γ-terpinene, terpinen-4-ol and α-terpinene. The oregano, 'Criollo', was rich in γ-terpinene and had lower thymol and trans-sabinene hydrate and higher α-terpinene and carvacrol contents than the other oregano species. 'Mendocino' had higher trans-sabinene hydrate and limonene than the other oregano species. 'Cordobes' and 'Compacto' had higher thymol content, radical scavenging activity and antioxidant activity in canola oil. [ABSTRACT FROM AUTHOR]

The purpose of this work was to determine the oxidative stability of roasted peanuts coated with prickly pear and algarrobo pod syrups. General composition, total phenolic compounds and radical scavenging activity were determined on prickly pear and algarrobo pod syrups. Chemical (peroxide value) and descriptive analyses were performed on samples of roasted peanuts, roasted peanuts with prickly pear syrup and roasted peanuts with algarrobo pod syrup stored at 23C for 112 days to determine protective effect of the syrup coating on the product stability. Prickly pear syrup showed higher moisture, protein, ash, lipid, phenolic compound content and lower carbohydrate content than algarrobo pod syrup. Prickly pear syrup also showed higher antioxidant activity (diphenyl picryl hydrazyl inhibition). Peroxide value, oxidized and cardboard intensity flavors increased and roasted peanutty intensity attribute decreased across the storage time for all studied products. Therefore, the addition of syrup coating provided protection against lipid oxidation. Peroxide value reached 10 meqO2/kg after 8.5 days in roasted peanuts, 20.7 days in roasted peanuts coated with prickly pear syrup and 29.5 days in roasted peanuts coated with algarrobo pod syrup at 23C. In consequence, algarrobo pod syrup had the highest protective effect in the roasted peanut product stored at room temperature. PRACTICAL APPLICATIONS The results of this work show advantages for using coatings that improve the stability of peanut products by making it more resistant to lipid oxidation and the development of rancid flavor. In this case, the edible coatings are elaborated using prickly pear and algarrobo pod syrups. These syrups could be applied on other similar food products with high lipid content to increase their shelf life and improve their stability, thus preventing loss of their sensory and nutritional quality. [ABSTRACT FROM AUTHOR]