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1.
J Sci Food Agric ; 104(12): 7567-7579, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38779961

RESUMO

BACKGROUND: Green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) herbal tea is popular due to its health-promoting properties. Information on its characteristic sensory profile is scarce and sensory tools to define product variation are needed. The storage conditions and time during its shelf-life are hypothesized to affect the product quality. RESULTS: Production batches from two producers spanning 5 years (n = 57) were analyzed using descriptive sensory analysis. Primary attributes (>30 median intensity; 100% occurrence frequency) included 'hay/dried grass', 'cooked oats', 'tobacco', 'honey' and 'caramel' aromas, and astringent mouthfeel. 'Cooked vegetables', 'green grass', 'stewed fruit', 'rooibos-woody', 'marmalade' and 'cardboard' aromas, sweet taste and bitter taste were secondary attributes (10-20 median intensity; 100% occurrence frequency). The same flavor attributes were present, except for sweet-associated and fruity notes. A sensory lexicon and sensory wheels for aroma and palate attributes were constructed from the data. The shelf-life stability of green rooibos was evaluated in moisture-impermeable (pouches) and moisture-permeable (sachets) packaging at 25 and 40 °C at 60% relative humidity over 24 weeks. Green rooibos samples stored in pouches at 4 °C were also evaluated. Storage in sachets led to moisture uptake (~10 g (100 g)-1 dry basis) and an increase in water activity (>0.6), causing degradation of chlorophyll and dihydrochalcones. Changes in color and sensory profile (decreased vegetal, cereal and cardboard aromas and increased sweet-associated and fruity aromas) were evident and more pronounced at the higher storage temperature. CONCLUSIONS: Storage at ≤25 °C in moisture-impermeable packaging material is recommended for green rooibos herbal tea. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Aspalathus , Armazenamento de Alimentos , Odorantes , Paladar , Aspalathus/química , Humanos , Odorantes/análise , Chás de Ervas/análise
2.
J Sci Food Agric ; 103(12): 5697-5708, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37078979

RESUMO

BACKGROUND: The shelf-life of a functional herbal tea-based beverage is important not only for consumer acceptability, but also for the retention of bioactive compounds. The present study aimed to clarify the role of common iced tea beverage ingredients (citric and ascorbic acids) on the shelf-life stability of an herbal tea-based beverage. A hot water extract of green Cyclopia subternata, also used as honeybush tea, was selected as the main ingredient because it provides different types of phenolic compounds associated with bioactive properties (i.e. xanthones, benzophenones, flavanones, flavones and dihydrochalcones). RESULTS: The model solutions were stored for 180 and 90 days at 25 and 40 °C, respectively. Changes in their volatile profiles and color were also quantified as they contribute to product quality. 3',5'-Di-ß-d-glucopyranosyl-3-hydroxyphloretin (HPDG; dihydrochalcone) and, to a lesser extent, mangiferin (xanthone), were the most labile compounds. Both compounds were thus identified as critical quality indicators to determine shelf-life. The stability-enhancing activity of the acids depended on the compound; ascorbic acid and citric acid enhanced the stability of HPDG and mangiferin, respectively. However, when considering all the major phenolic compounds, the base solution without acids was the most stable. This was also observed for the color and major volatile aroma-active compounds [α-terpineol, (E)-ß-damascenone, 1-p-menthen-9-al and trans-ocimenol]. CONCLUSION: The addition of acids, added for stability and taste in ready-to-drink iced tea beverages, could thus have unwanted consequences in that they could accelerate compositional changes and shorten the shelf-life of polyphenol-rich herbal tea beverages. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Fabaceae , Chás de Ervas , Xantonas , Chás de Ervas/análise , Fabaceae/química , Bebidas/análise , Fenóis/química , Ácido Ascórbico/química , Chá , Extratos Vegetais/química
3.
Phytother Res ; 36(11): 4051-4062, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36197117

RESUMO

Evidence for the anti-diabetic actions of camellia and herbal tea in diabetic patients has not been summarized. Several data sources were searched for randomized trials assessing the effect of different teas on cardiometabolic risk factors in T2D subjects. Two independent reviewers extracted relevant data and assessed the risk of bias. Results were summarized using mean differences (MDs) based on a random model. Sixteen studies (19 trials, N = 832) fulfilled the eligibility criteria. Mean differences were measured for body weight, body mass index, fasting blood glucose, glycosylated hemoglobin, a homeostatic model for insulin resistance, high and low-density lipoproteins, triglycerides, and systolic and diastolic blood pressure. No effects on total cholesterol and waist circumference were observed when either camellia or herbal tea was consumed. Tea produced moderate regulatory effects on adipose, glycemic control, lipid profiles, and blood pressure. In terms of efficacy, camellia and herbal teas yield different benefits in regulating metabolism. This discovery has some implications for clinical research and drug development. However, more high-quality trials are needed to improve the certainty of our estimates.


Assuntos
Camellia , Doenças Cardiovasculares , Diabetes Mellitus Tipo 2 , Chás de Ervas , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Chás de Ervas/análise , Ensaios Clínicos Controlados Aleatórios como Assunto , Chá , Doenças Cardiovasculares/prevenção & controle , Glicemia/análise
4.
Molecules ; 27(15)2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35956912

RESUMO

Agropyron repens (L.) P. Beauv. (couch grass) is a world-wide infesting rhizomatous plant with pharmacological applications. Chemical research is focused on its allelopathic and anti-inflammatory components, which are mainly present in the essential oil. Conversely, the aqueous extracts have been sparingly investigated, although the herbal tea is by far the most used formulation. To fill the gap, the metabolic profile of Agropyron repens rhizome herbal tea was investigated by electrospray ionization (ESI) tandem-mass spectrometry (MS/MS); the phenolic profile was investigated by HPLC-PDA-ESI-MS/MS. ESI-MS fingerprinting was provided, evidencing diagnostic ions for saccharides, organic acids and amino acids. The HPLC-PDA-ESI-MS/MS analysis evidenced at least 20 characteristic phenolic compounds, the most representative being caffeoyl and feruloyl quinic esters, followed by coumaric, caffeic and ferulic acids, and hesperidin among flavonoids. In addition, the essential amino acid tryptophan was identified for the first time. The results suggest new perspectives of applications for Agropyron repens rhizome.


Assuntos
Agropyron , Chás de Ervas , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/química , Metaboloma , Fenóis/análise , Extratos Vegetais/química , Rizoma/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Chás de Ervas/análise
5.
Environ Monit Assess ; 194(8): 534, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35764709

RESUMO

The concentrations of arsenic, cadmium, and lead in infusion tea bags of Camellia sinensis (tea), Pimpinella anisum (anise), Matricaria recutita (chamomile), Peumus boldus (boldo), and Cymbopogon citratus (lemongrass) were determined by graphite furnace atomic absorption spectroscopy (GFAAS) for four commercial brands sold in Tacna, Peru, to compare these concentrations with international standards. The moderate level of arsenic obtained for C. sinensis (0.294 mg kg-1) exceeded the Codex Alimentarius standard for three of the four analyzed brands, while the level of arsenic in P. boldus (0.220 mg kg-1) exceeded the same standard and the Mercado Común del Sur (MERCOSUR) parameters for only one brand. The moderate level of cadmium outlined in the Codex Alimentarius and by the World Health Organization (WHO) was exceeded by two infusion tea bag brands of M. recutita (0.210 mg kg-1) and one brand of C. citratus (0.134 mg kg-1). Finally, based on the MERCOSUR parameters, moderate levels of lead were exceeded by only one brand of C. citratus (0.535 mg kg-1). To evaluate possible health risks, we also calculated the hazard index (HI) of the heavy metals in the target herbal tea bags. The values obtained were less than 1, showing negligible noncarcinogenic health risks for consumers. Despite this information and because of the elevated concentrations of arsenic, cadmium, and lead obtained in some of our results, we suggest more detailed studies to obtain more information about the potential toxicity of these products to humans.


Assuntos
Arsênio , Chás de Ervas , Arsênio/análise , Cádmio/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Chumbo , Peru , Chá/química , Chás de Ervas/análise
6.
Molecules ; 26(21)2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34770903

RESUMO

Tea (Camellia sinensis) and herbal tea have been recognized as rich sources of bioactive constituents with the ability to exert antioxidant actions. The aims of this study were to analyze phenolic, carotenoid and saccharide contents in a set of Vietnamese tea and herbal tea and compare the results with those of green and black teas marketed in the U.S. In total, 27 phenolics, six carotenoids and chlorophylls, and three saccharides were quantitatively identified. Catechins, quercetin glycosides and chlorogenic acid were the predominating phenolics in the teas, with the concentrations following the order: jasmine/green teas > oolong tea > black tea. Lutein was the dominant carotenoid in the teas and its concentrations were generally found to be higher in the jasmine and green teas than in the oolong and black teas. The study showed that the green teas originating in Vietnam had much higher levels of phenolics and carotenoids than their counterparts stemming from another country. The application of partial least squares discriminant analysis (PLS-DA) as a chemometric tool was able to differentiate phenolic profiles between methanolic extracts and tea infusions. Through principal component analysis (PCA), the similarities and dissimilarities among the jasmine, green, oolong, black teas and herbal teas were depicted.


Assuntos
Camellia sinensis/química , Carotenoides/análise , Fenóis/análise , Açúcares/análise , Chá/química , Chás de Ervas/análise , Flavonoides/análise , Compostos Fitoquímicos/análise , Extratos Vegetais/análise , Solventes , Vietnã
7.
Molecules ; 26(23)2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34885694

RESUMO

Volatile composition is an important feature that determines flavor, which actively affects the overall evaluation of chrysanthemum tea. In this study, HS-GC-IMS (headspace-gas chromatography-ion mobility spectrometry) was performed to characterize the volatile profiles of different chrysanthemum tea subtypes. Forty-seven volatiles of diverse chemical nature were identified and quantified. Partial least squares discriminant analysis (PLS-DA) revealed that four chrysanthemum teas were distinct from each other based on their volatile compounds. Furthermore, this work provides reference methods for detecting novel volatile organic compounds in chrysanthemum tea plants and products.


Assuntos
Chrysanthemum/química , Chá/química , Chás de Ervas/análise , Compostos Orgânicos Voláteis/química , Camellia sinensis/química , Aromatizantes/química , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Mobilidade Iônica , Análise de Componente Principal , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/isolamento & purificação
8.
Molecules ; 26(3)2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33499197

RESUMO

Teas and various herbal teas are well-known beverages and are commonly consumed around the world. In this study, we focused on kuromoji tea. Kuromoji is a deciduous shrub of the Lauraceae family, and the plucked leaves and branches have been drunk as a tea in production areas for a long time. However, no studies have investigated the subjective and physiological effects of kuromoji tea. In this study, the effects of kuromoji tea were examined on the basis of the measurements of heart rate variability and cerebral blood flow, core body temperature and subjective assessments. Moreover, the results of this study showed that a pleasant subjective feeling could be obtained by sniffing the aroma of kuromoji teas, especially tea leaves. It was also found that the aroma of kuromoji teas has the potential to stimulate saliva secretion and increase subjective and physiological excitements in the oral cavity. 1,8-Cineole, linalool, terpinen-4-ol, carvone and geraniol were determined in both kuromoji leaves and branches. In this study, the beneficial effects of kuromoji teas when drunk conventionally were investigated.


Assuntos
Lindera/química , Odorantes/análise , Chás de Ervas/análise , Temperatura Corporal , Estudos Cross-Over , Cromatografia Gasosa-Espectrometria de Massas , Frequência Cardíaca , Humanos , Inalação , Japão , Masculino , Percepção Olfatória/fisiologia , Oxiemoglobinas/metabolismo , Microextração em Fase Sólida , Escala Visual Analógica , Adulto Jovem
9.
Molecules ; 26(23)2021 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-34885955

RESUMO

Rosemary (Rosmarinus officinalis) and basil (Ocimum sanctum Linn) are mostly used as herbal teas, made by steeping whole or ground herbs in boiling water. Hence, it is important to know the effect of boiling time on the bioactivity of these herbs. The effect of different boiling times (5, 10, and 15 min) on the antioxidant and antimicrobial properties, and some selected phenolic compounds of these herbs was examined in this study. Experimental results revealed that basil displayed the highest total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity when it was boiled for 5 min, and the lowest TPC was obtained when it was boiled for 15 min. On the other hand, rosemary had the highest TPC, TFC, and antioxidant potential after being boiled for 15 min, while it had the lowest after being boiled for 5 min. There was no growth inhibition of rosemary extracts against gram-negative bacteria, whereas higher growth inhibition was observed against gram-positive bacteria. The MIC and MBC of rosemary ethanolic extract against Listeria monocytogenes were 5 and 5 mg/mL and against B. subtilis were 10 and 10 mg/mL, respectively. While MIC and MBC of methanolic extract against L. monocytogenes were 5 and 5 mg/mL and against Bacillus subtilis were and 5 and 5 mg/mL, respectively. Salicylic acid was the most abundant (324.7 mg/100 g dry weight (dw)) phenolic compound in the rosemary sample boiled for 5 min, and acetyl salicylic acid was the most abundant (122.61 mg/10 g dw) phenolic compound in the basil sample boiled for 15 min.


Assuntos
Anti-Infecciosos/química , Ocimum basilicum/química , Rosmarinus/química , Chás de Ervas , Anti-Infecciosos/farmacologia , Flavonoides/química , Flavonoides/farmacologia , Manipulação de Alimentos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Temperatura Alta , Plantas Medicinais/química , Polifenóis/química , Polifenóis/farmacologia , Chás de Ervas/análise
10.
Anal Bioanal Chem ; 412(24): 6341-6349, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32173791

RESUMO

A lab-made stirring extraction unit based on a selective monolithic solid was developed. The monolith was formed by interconnected carbon nanotubes which were covered by a thin polymeric layer, where specific cavities were generated to provide selective recognition sites in the material. To reach this goal, a water-in-oil (W/O) medium internal phase emulsion (40/60 w/w%), was prepared and photopolymerized. The polymerization reaction took place in the organic or external phase containing the carbon nanotubes, polymeric monomers (cross-linker and functional monomer) and a molecule template. Therefore, it was possible to coat the nanotubes with a layer of molecularly imprinted polymer (MIP) with the target analyte while forming a monolithic and macroscopic structure. The developed selective monolithic stirring extraction units were applied for the determination of secbumeton and structurally related compounds (triazine herbicides) in peppermint mint and tea samples. Their adsorption capacity and selectivity were also compared with a non-imprinted polymer (NIP). Finally, the performance of the method was evaluated for quantitative analysis, achieving limits of detection (LODs) between 0.4 and 2.5 µg·L-1. The intra- and inter-day precision of the method was also evaluated as relative standard deviation, observing values which ranged from 3% to 9% and 9% to 15%, respectively. Graphical Abstract.


Assuntos
Herbicidas/isolamento & purificação , Polímeros Molecularmente Impressos/química , Nanotubos de Carbono/química , Microextração em Fase Sólida/métodos , Triazinas/isolamento & purificação , Reagentes de Ligações Cruzadas/química , Herbicidas/análise , Limite de Detecção , Mentha piperita/química , Metacrilatos/química , Impressão Molecular/métodos , Polimerização , Chá , Chás de Ervas/análise , Triazinas/análise
11.
Ecotoxicol Environ Saf ; 187: 109859, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677573

RESUMO

Chrysanthemum (Dendranthema grandiflora) flowers are consumed as a popular, traditional herbal tea worldwide. During tea infusion with hot water pesticide residues in chrysanthemum flowers can be transferred into tea solution, posing potential health risks to consumers. Using greenhouse chrysanthemum this study systematically investigated the transfer of metalaxyl-M, fludioxonil, cyantraniliprole, thiamethoxam, and clothianidin (a major metabolite of thiamethoxam) from dry chrysanthemum flowers to tea solution at a range of infusion repetitions, duration and water temperature. The tested pesticides were released into tea solution at varying degrees, and the maximum transfer percentage was 59.9%, 9.8%, 29.4%, 88.2% and 68.4% for metalaxyl-M, fludioxonil, cyantraniliprole, thiamethoxam, and clothianidin, respectively. The transfer of pesticides into tea solution generally increased with increasing pesticide water solubility, water temperature, infusion duration, and pesticide concentrations in dry chrysanthemum flowers, but decreased with increasing octanol-water partition coefficient and the number of infusion repetitions. Risk quotient for pesticide intake via consuming tea solution of chrysanthemum flowers (one and two times of recommended pesticide dosages) ranged from <0.00003 to 0.0924, indicating a low health risk. This study provides useful information for risk assessment of pesticide residues in greenhouse chrysanthemum flowers and may help establish realistic maximum residue limit of pesticides in chrysanthemum flowers and tea solution.


Assuntos
Chrysanthemum/química , Flores/química , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Chás de Ervas/análise , Medição de Risco , Solubilidade
12.
Mikrochim Acta ; 187(8): 446, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32676763

RESUMO

Accurate-controlled sized graphene quantum dots (GQDs) have been used as an analytical nanoprobe for detecting curcumin as a function of the photoluminescent quenching upon increasing concentrations of the analyte. Regarding the importance of curcumin nanoparticles in nutraceutical food, the analytical method described herein was also proven for the discrimination of curcumin remaining in free solution from that encapsulated into water-soluble nanomicelles of ca. 11 nm. This recognition is based on the displacement of GQD emission when interacting with both curcumin species. Maximum emission wavelength of GQDs suffers a gradual quenching as well as a red-shifting upon increasing concentrations of free curcumin (from 458 to 490 nm, exciting at 356 nm). On the other hand, in the presence of nanocurcumin, GQD photoluminescent response only displays a quenching effect (458/356 nm). The sensitivity of the described method in terms of detection limits was 0.3 and 0.1 µg mL-1 for curcumin and nanocurcumin, respectively. The applicability of the photoluminescent probe for the quantification and discrimination between both curcumin environments was demonstrated in nutraceutical formulations namely functional food capsules and fortified beverages such as ginger tea. Graphical abstract.


Assuntos
Curcumina/análise , Corantes Fluorescentes/química , Grafite/química , Nanopartículas/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Curcumina/química , Suplementos Nutricionais/análise , Zingiber officinale/química , Limite de Detecção , Chás de Ervas/análise
13.
Molecules ; 25(16)2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32824271

RESUMO

Gynostemma pentaphyllum (thumb.) Makino is a functional herbal tea commonly used in Asian countries and regions to reduce blood lipid levels. G. pentaphyllum saponin is the main component, but there are still a large number of components with lipid-lowering activity that have not been found. In this study, 10 novel dammarane-type saponins, (1-10) and a known one (11) were isolated from G. pentaphyllum. Ten new compounds were identified and named as yunnangypenosides A-J (1-10), and another known one (11) was also obtained. Their chemical structures were determined by MS, NMR spectroscopic analyses. Moreover, the cytotoxicities on human HepG-2 hepatocellular carcinoma cells of these isolates were evaluated, and the results showed that compounds 1-11 had no obvious cytotoxicity. Finally, all these compounds were evaluated for their lipid-lowering effect by means of the oil red O staining method. Ten compounds could significantly reduce lipid levels except of 2, especially 8 exhibite the strongest hypolipidemia activity.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Gynostemma/química , Hipolipemiantes/farmacologia , Extratos Vegetais/farmacologia , Saponinas/farmacologia , Triterpenos/química , Carcinoma Hepatocelular/patologia , Proliferação de Células , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Estrutura Molecular , Saponinas/química , Chás de Ervas/análise , Damaranos
14.
Molecules ; 25(9)2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32384789

RESUMO

Genus Stachys, the largest genera of the family Lamiaceae, and its species are frequently used as herbal teas due to their essential oils. Tubers of some Stachys species are also consumed as important nutrients for humans and animals due to their carbohydrate contents. Three new neo-clerodane diterpene peroxides, named stachaegyptin F-H (1, 2, and 4), together with two known compounds, stachysperoxide (3) and stachaegyptin A (5), were isolated from Stachys aegyptiaca aerial parts. Their structures were determined using a combination of spectroscopic techniques, including HR-FAB-MS and extensive 1D and 2D NMR (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOESY) analyses. Additionally, a biosynthetic pathway for the isolated compounds (1-5) was discussed. The chemotaxonomic significance of the isolated diterpenoids of S. aegyptiaca in comparison to the previous reported ones from other Stachys species was also studied.


Assuntos
Diterpenos Clerodânicos/análise , Compostos Fitoquímicos/análise , Componentes Aéreos da Planta/química , Extratos Vegetais/análise , Stachys/química , Vias Biossintéticas , Classificação , Diterpenos/análise , Diterpenos/isolamento & purificação , Diterpenos Clerodânicos/química , Diterpenos Clerodânicos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Peróxidos/análise , Peróxidos/isolamento & purificação , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Chás de Ervas/análise
15.
J Sci Food Agric ; 100(11): 4226-4236, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32378210

RESUMO

BACKGROUND: The elemental composition of herbal infusions and teas has not been sufficiently investigated. It could potentially be used for defining fingerprints for individual herbal / tea infusions, differentiation of botanical families, detecting the influence of packaging, and other purposes. The objective of this study was to determine the elemental composition, including the trace element content, of various herbal infusions and teas by means of total reflection X-ray fluorescence analysis (TXRF), with a chemometrics approach using principal component analysis (PCA). RESULTS: This study determined the elemental composition of various herbal infusions and teas, including trace elements, using total reflection X-ray fluorescence (TXRF). The methodology for the sample preparation was established, including the multiple-steepings procedure for the two tea samples (Oolong and Pu-erh). Data from 29 samples were collected. We hypothesized that the elemental content of infusions could reflect certain features, such as the influence of processing and the type of tea. CONCLUSION: A chemometric approach (PCA) was applied, and differences between teas and herbal infusions were found. This was further corroborated by explicit differentiation of one botanical family, Theaceae. The influence of packaging (tea bags) on herbal material was identified. The three types of tea (Camellia sinensis) appeared to be separated with PCA, and elemental concentrations in Pu-erh changed with multiple steepings.


Assuntos
Espectrometria por Raios X/métodos , Chás de Ervas/análise , Oligoelementos/análise , Fluorescência , Análise de Componente Principal
16.
J Sci Food Agric ; 100(5): 1904-1912, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31825526

RESUMO

BACKGROUND: A new solvent, deep eutectic solvent, in which there is growing interest, has been prepared and used as an extraction solvent in the dispersive liquid-liquid method of microextraction. To prepare the solvent, dichloroacetic acid, l-menthol, and n-butanol are mixed at a molar ratio of 4:1:1 and the deep eutectic solvent is formed after heating. Then a dispersive liquid-liquid microextraction method using the prepared solvent is used for the extraction and preconcentration of some pesticides from an aqueous sample. To carry out the procedure, the deep eutectic solvent is mixed with methanol and rapidly injected by a syringe into the aqueous sample containing the analytes. After centrifuging, an aliquot of the sedimented phase is injected into the gas chromatograph. The influence of several variables on the extraction efficiency was investigated and optimized. RESULTS: Extraction recoveries and enrichment factors were obtained in the ranges of 53-86% and 1760-2853, respectively. The intra- (n = 6) and inter-day (n = 5) precision of the method was satisfactory, with relative standard deviations ≤ 7% obtained at two concentrations of 10 and 50 µg L-1 of each analyte. Moreover, detection and quantification limits for the target analytes were obtained in the ranges of 0.11-0.23 and 0.38-0.74 µg L-1 , respectively. CONCLUSION: Different samples, including green tea, rose water, lemon balm, mint, and pussy willow distillates were analyzed successfully using the method that was developed, and chlorpyrifos was found in rose water at a concentration of 17 ± 1 µg L-1 (n = 3). © 2019 Society of Chemical Industry.


Assuntos
Microextração em Fase Líquida/métodos , Resíduos de Praguicidas/isolamento & purificação , Chá/química , Chás de Ervas/análise , Cromatografia Gasosa , Contaminação de Alimentos/análise , Limite de Detecção , Microextração em Fase Líquida/instrumentação , Resíduos de Praguicidas/análise , Solventes/química
17.
Environ Geochem Health ; 42(9): 2853-2863, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32166521

RESUMO

The total mean ∑[Formula: see text] in samples were from 75.3 to 387.0 ng/g dry weight (d.w) and showed high value in black dry tea, followed by herbal, oolong, and green tea. The mean ∑[Formula: see text] (a combination of benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene) values were 54.3 ng/g, 16.4 ng/g, 14.2 ng/g, and 6.6 ng/g for black, herbal, green, and oolong teas, respectively. Concentration for benzo[a]pyrene (BaP) was from 0.4 to 35.8 ng/g, and the BaP equivalent concentration values ranged from 0.3 to 48.1 ng/g. There was only 1 black tea sample that BaP concentration exceeded the maximum level according to European Union (EU) standards. Tea samples marketed in Vietnam showed insignificant difference with the samples from other origins by same analytical method. Black teas showed high PAHs contents in dry tea samples but the released percentage of sum of PAHs from tea-to-tea infusion was lower than that in other tea type samples. The released percentages of PAH4 from tea-to-tea infusion were 40.7, 15.4, and 1.9 for green, herbal, and black tea. High temperature in black tea manufacturing processes might reduce essential oil content in tea that might effect on the PAHs partially release into the infusion. Indeed, based on EU regulations, we may conclude that tea consumers are safe in risk of exposure to PAHs obtained from teas.


Assuntos
Exposição Dietética/análise , Contaminação de Alimentos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Chá/química , Benzo(a)pireno/análise , Camellia sinensis/química , Crisenos/análise , Exposição Dietética/efeitos adversos , Fluorenos/análise , Humanos , Folhas de Planta/química , Medição de Risco/métodos , Chás de Ervas/análise , Vietnã
18.
Anal Bioanal Chem ; 411(27): 7233-7249, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31511948

RESUMO

Pyrrolizidine alkaloids (PA) and PA-N-oxides (PANO) are a large group of secondary plant metabolites comprising more than 660 compounds. Exhibiting geno- and hepatotoxic properties, they are responsible for multiple cases of food and feed poisoning over the last 100 years. For food and feed safety reasons, relevant PA/PANO should be monitored extensively in the main sources of PA/PANO intake. In this study, a sensitive analytical method was developed for detecting a broad range of 44 commercially available PA/PANO compounds, and in-house validation procedures were performed for several (herbal) teas. Various extraction solvents and procedures, as well as solid phase extraction materials for sample clean-up and analyte concentration, were tested to establish the methods' efficiency and effectiveness. Chromatographic conditions were optimised to obtain the best possible separation of isomers for the 44 PA/PANO analytes. The final method was proven very sensitive and accurate, with detection limits ranging from 0.1 to 7.0 µg/kg and precisions between 0.7 and 16.1%. For 40 of the analytes, the recovery rates ranged from 60.7 to 128.8%. The applicability and trueness of the method were examined by analysing tea samples from a local supermarket and comparing them to a reference material. At least one PA/PANO analyte was detected in 17 of the 18 samples under investigation, and the sum contents of the samples ranged from 0.1 to 47.9 µg/kg. Knowledge of the PA/PANO composition in a sample can be used to indicate the botanical origin of the impurity and, thus, the geographical region of cultivation.


Assuntos
Cromatografia Líquida/métodos , Alcaloides de Pirrolizidina/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Chá/química , Chás de Ervas/análise , Contaminação de Alimentos/análise , Limite de Detecção , Reprodutibilidade dos Testes
19.
J Nat Prod ; 82(2): 403-406, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30688071

RESUMO

The aim of the present work was to study the occurrence of mycotoxins [aflatoxins (1-4), 3-acetyldeoxyniavlenol (5), 15-acetyldeoxynivalenol (6), nivalenol (7), HT-2 (8), T-2 (9), ochratoxin A (10), zearalenone (11), enniatin A (12), enniatin A1 (13), enniatin B (14), enniatin B1 (15), and beauvericin (16)] present in potable products derived from herbal teas. Analysis was carried out by liquid chromatography coupled to ion-trap tandem mass spectrometry (LC-MS/MS-IT) after a dispersive liquid-liquid microextraction procedure (DLLME) was conducted. The DLLME method was applied to 52 commercial samples of chamomile, chamomile with anise, chamomile with honey, linden, pennyroyal mint, thyme, valerian, and horsetail beverages. The results obtained showed that the following mycotoxins were detected in the samples: 2 (19.1 to 134.7 µg/L), 3 (below the limit of quantification), and 4 (2.2 to 13.5 µg/L). Also, 6 was detected in one sample at 112.5 µg/L, and 14 was detected only in two samples, although at very low concentration levels. Pennyroyal mint and thyme showed the highest concentration levels of mycotoxins. A risk assessment, however, showed negative results regarding the consumption of herbal tea beverages and the presence of mycotoxins.


Assuntos
Micotoxinas/análise , Chás de Ervas/análise , Bebidas/análise , Cromatografia Líquida , Suplementos Nutricionais , Microextração em Fase Líquida , Micotoxinas/toxicidade , Medição de Risco , Espectrometria de Massas em Tandem
20.
Molecules ; 24(6)2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875921

RESUMO

A method for detecting the organophosphorus pesticides residue and aflatoxins in China herbal tea has been developed by UPLC-MS/MS coupled with vortex-assisted dispersive liquid-liquid microextraction (DLLME). The extraction conditions for vortex-assisted DLLME extraction were optimized using single-factor experiments and response surface design. The optimum conditions for the experiment were the pH 5.1, 347 µL of chloroform (extraction solvent) and 1614 µL of acetonitrile (dispersive solvent). Under the optimum conditions, the targets were good linearity in the range of 0.1 µg/L⁻25 µg/L and the correlation coefficient above 0.9998. The mean recoveries of all analytes were in the ranged from 70.06%⁻115.65% with RSDs below 8.54%. The detection limits were in the range of 0.001 µg/L⁻0.01µg/L. The proposed method is a fast and effective sample preparation with good enrichment and extraction efficiency, which can simultaneously detect pesticides and aflatoxins in China herbal tea.


Assuntos
Aflatoxinas/análise , Praguicidas/análise , Chás de Ervas/análise , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Microextração em Fase Líquida , Solventes/química , Espectrometria de Massas em Tandem
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