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1.
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
2.
Food Chem ; 302: 125336, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419772

RESUMO

This study reports a stepwise optimization of switchable liquid-liquid microextraction (SLLME) for cobalt determination by flame atomic absorption spectrometry (FAAS) coupled with a slotted quartz tube (SQT). The main purpose of this study was to develop an accurate and sensitive analytical method for cobalt. Extraction method was used to separate and preconcentrate cobalt from sage tea and vitamin B12 samples after complexing with a Schiff base ligand. 107.7 folds enhancement in detection power under the optimum conditions was recorded with respect to direct FAAS. This enhancement correlated to 3.1 µg/L limit of detection and 10 µg/L limit of quantification. The SLLME-SQT-FAAS method was linear over a broad concentration range and low %RSD values established high precision for the method. Appreciable percent recovery results (94-108%) obtained from spiked sage sample and from cobalamin also validated the accuracy of the method.


Assuntos
Cobalto/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica/métodos , Chás de Ervas/análise , Vitamina B 12/análise , Limite de Detecção , Quartzo , Reprodutibilidade dos Testes , Salvia officinalis/química , Bases de Schiff/química , Espectrofotometria Atômica/instrumentação , Vitamina B 12/química
3.
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
4.
Food Funct ; 10(9): 5939-5951, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31469370

RESUMO

In order to characterize and study the bioactivities of individual plant species and to determine how these characteristics are modified when preparing blends, five different plant species were selected: Erica australis L., Genista tridentata L., Melissa officinalis L., Mentha spicata L., and Prunella vulgaris L. Infusions prepared from each plant species and from three selected mixtures were analyzed in terms of nutritional values, phenolic compositions, and bioactive properties (antioxidant, antimicrobial, cytotoxic, and anti-inflammatory activities). The major compound detected in M. officinalis, M. spicata, and P. vulgaris infusions was rosmarinic acid, whilst in E. australis and G. tridentata flavonoid derivatives such as quercetin and genistein were identified. P. vulgaris and M. officinalis presented the best results in TBARS and OxHLIA assays, respectively. M. spicata and all mixtures presented anti-inflammatory activity. M. spicata showed the best cytotoxic properties and antimicrobial activity, and none of the infusions showed hepatotoxicity for non-tumour cells.


Assuntos
Genista/química , Melissa/química , Mentha spicata/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Prunella/química , Chás de Ervas/análise , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Flavonoides/química , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Fenóis/química , Fenóis/farmacologia , Células RAW 264.7
5.
Plant Foods Hum Nutr ; 74(3): 266-276, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31243622

RESUMO

Herbal teas are used as therapeutic vehicles in many forms of traditional medicine and are a popular global beverage. The purpose of this scoping review was to examine the evidence relating to the clinical efficacy and safety of herbal teas, and to identify the main research themes and gaps in knowledge to inform further work. A scoping review methodology was followed that set out the research question and described the sourcing, selection and analysis of studies. Overall, a total of 145 research publications were retrieved from global bibliographic databases, and after applying exclusion criteria, 21 remained. These studies looked at herbal tea use in female health, diabetes, heart disease and weight loss, with plant species including lavender, chamomile, fenugreek, stinging nettle, spearmint, hibiscus, yerba maté, echinacea and combinations of herbs. Observational studies explored associations between herbal tea consumption and cancer risk, liver health, and the risks linked to the consumption of environmental contaminants in the plant material. Despite plant materials being the basis for drug discovery, and the popularity of herbal teas, the number of articles exploring clinical efficacy and safety is small. In this review we discuss how herbal teas may be beneficial in some areas of clinical and preventative health, and what further research is required to understand whether regular consumption can contribute to healthy living more generally.


Assuntos
Medicina Tradicional , Compostos Fitoquímicos/análise , Plantas Medicinais , Chás de Ervas/análise , Biodiversidade , Humanos , Medicina Preventiva
6.
Food Chem Toxicol ; 130: 142-153, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31112705

RESUMO

In this study five types of herbal teas were used to quantify the effect of comminution of the leaves on resulting PA exposure. Results show that PA levels extracted from intact leaves were consistently lower than from comminuted tea leaves. The Margin of Exposure (MOE) approach was applied to evaluate the consequences of this difference for the associated risks in the scenario of lifetime exposure. Furthermore, we considered medicinal use of these teas for shorter-than-lifetime exposure scenarios, and also analysed the risks of shorter-than-lifetime use of eight herbal medicines and 19 previously analysed plant food supplements. This analysis revealed that shorter-than-lifetime use resulted in MOE values < 10,000 upon use for 40-3450 weeks during a lifetime, with for only a limited number of herbal teas and medicines use of two weeks a year (150 weeks during a 75 year lifetime) would still raise a concern. It is concluded that taking more realistic conditions into account markedly reduces the concerns raised for these herbal preparations. These results also illustrate the need for development of a generally accepted method for taking short term exposure into account in risk assessment of compounds that are genotoxic and carcinogenic.


Assuntos
Preparações de Plantas/química , Preparações de Plantas/toxicidade , Alcaloides de Pirrolizidina/toxicidade , Chás de Ervas/análise , Chás de Ervas/toxicidade , Carcinógenos , Humanos , Modelos Biológicos , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Folhas de Planta/química , Plantas Medicinais/química , Alcaloides de Pirrolizidina/química , Fatores de Risco
7.
J Agric Food Chem ; 67(17): 4967-4975, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30955332

RESUMO

Rooibos tea ( Aspalathus linearis) is a well-known South African herbal tea enjoyed worldwide. Limited reports indicate the potential of rooibos tea to alter the activity of certain cytochrome P450 (CYP450) isozymes. In this study, the phytochemical investigation of MeOH extract of A. linearis (leaves and stems) resulted in the isolation and characterization of 11 phenolic compounds. The MeOH extract exhibited significant inhibition of the major human CYP450 isozymes (CYP3A4, CYP1A2, CYP2D6, CYP2C9, and CYP2C19). The strongest inhibition was observed by the extract for CYP3A4 (IC50 1.7 ± 0.1 µg/mL) followed by CYP2C19 (IC50 4.0 ± 0.3 µg/mL). Among the tested phytochemicals, the most potent inhibitors were isovitexin on CYP3A4 (IC50 3.4 ± 0.2 µM), vitexin on CYP2C9 (IC50 8.0 ± 0.2 µM), and thermopsoside on CYP2C19 (IC50 9.5 ± 0.2 µM). The two major, structurally related compounds aspalathin and nothofagin exhibited a moderate pregnane-X receptor (PXR) activation, which was associated with increased mRNA expression of CYP3A4 and CYP1A2, respectively. These results indicate that a high intake of nutraceuticals containing rooibos extracts may pose a risk of herb-drug interactions when consumed concomitantly with clinical drugs that are substrates of CYP enzymes.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Aspalathus/química , Sistema Enzimático do Citocromo P-450/química , Preparações de Plantas/química , Receptor de Pregnano X/química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Aspalathus/metabolismo , Linhagem Celular , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Inocuidade dos Alimentos , Humanos , Folhas de Planta/química , Preparações de Plantas/metabolismo , Receptor de Pregnano X/genética , Receptor de Pregnano X/metabolismo , Chás de Ervas/análise
8.
Food Funct ; 10(4): 2186-2197, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30942219

RESUMO

A new acidic polysaccharide (GPTP-3) with a molecular weight of 2.49 × 106 Da was extracted and purified from Gynostemma pentaphyllum tea. Monosaccharide analysis revealed that GPTP-3 mainly comprised mannose (20.4%), glucuronic acid (17.4%), glucose (33.4%), and galactose (21.4%) (parentheses indicate the molar percentages). Immunostimulating assays indicated that GPTP-3 could markedly promote the secretion of NO, TNF-α, IL-1ß, and IL-6 in murine macrophage RAW264.7. TLR4 was found to be a recognized target of GPTP-3. Moreover, TLR4-related mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt, including ERK, JNK, p38, and Akt, were rapidly activated by GPTP-3 in RAW264.7 cells. Furthermore, GPTP-3 was found to induce the nuclear translocation of NF-κB subunit p65. All these findings suggest that MAPK, PI3K/Akt, and NF-κB pathways are involved in GPTP-3-induced macrophage activations, and GPTP-3 has the potential to be developed as a functional food with immunomodulatory functions.


Assuntos
Gynostemma/química , Fatores Imunológicos/farmacologia , Macrófagos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Animais , Fatores Imunológicos/química , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Extratos Vegetais/química , Polissacarídeos/química , Células RAW 264.7 , Chás de Ervas/análise , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
9.
Food Addit Contam Part B Surveill ; 12(3): 199-208, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30961455

RESUMO

The occurrence of 12 mycotoxins has been analysed by liquid chromatography - time of flight mass spectrometry in the batch of 60 herbal teas purchased from drugstores in Latvia. Among the dry tea samples, 90% were positive for one to eight mycotoxins. Enniatin B and deoxynivalenol (DON) were the most frequently detected mycotoxins in 55% and 45% of the samples, respectively. DON reached the highest level, from 129 µg kg-1 in herbal blend to 5,463 µg kg-1 in wormwood tea. Ochratoxin A (OTA) and aflatoxin B1 (AFB1) were found in 10% and 20% of the samples at the concentrations ranged between 2.99-30.3 µg kg-1 and 3.40-23.7 µg kg-1. Studies of the tea infusion process indicated that 32-100% of DON and zearalenone present in dry teas were extracted into the infusions. Dietary exposure assessment was performed, using the determined mycotoxin levels and the available consumption data.


Assuntos
Contaminação de Alimentos , Micotoxinas/química , Chás de Ervas/análise , Cromatografia Líquida de Alta Pressão , Exposição Dietética , Análise de Alimentos , Humanos , Letônia , Reprodutibilidade dos Testes , Medição de Risco , Espectrometria de Massas em Tandem
10.
J Environ Sci Health B ; 54(1): 14-19, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30821203

RESUMO

Salvia officinalis L. is a popular herb widely used in culinary, cosmetic, and medicinal preparations, and also as an ornamental plant. Sage crops are threatened by many diseases, such as gray mold, powdery mildew, and leaf spot, by weeds, and by pests, such as aphids. Use of crop protection products may lead to presence of pesticide residues in this herb. The aim of this work was to study presence of pesticide residues in the herb, S. officinalis L., available on the retail market in Poland, to verify their compliance with the maximum residue levels (MRLs) and to assess the chronic and acute risks associated with consumption of this herb and infusions prepared from contaminated sage plants. Ninety active substances of pesticides were analyzed, including all active substances registered in Poland for protection of the sage. Five active substances were found, one fungicide - boscalid and four insecticides: chlorpyrifos, pp'-DDT, dimethoate (residue levels above MRL) and indoxacarb. The chronic and acute exposure to pesticide residues consumed with sage did not exceed 0.02% of the acceptable daily intake (ADI) and 0.1% of the acute reference dose (ARfD), respectively.


Assuntos
Exposição Dietética/efeitos adversos , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Salvia officinalis/química , Produtos Agrícolas/química , Humanos , Nível de Efeito Adverso não Observado , Polônia , Medição de Risco , Chás de Ervas/análise
11.
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
12.
Food Chem ; 287: 258-264, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30857697

RESUMO

In order to value J. glutinosa DC (rock tea), we characterised its phenolic profile and antioxidant activity. The study was performed in aqueous extracts before and after a simulated in vitro digestion to obtain data regarding phenolics bioavailability. Methanolic extracts were also analysed for comparison purposes. Phytochemical profiles were determined by high-performance liquid chromatography with mass spectrometric detection, whereas total phenolic content (TPC) and antioxidant assays were performed by conventional spectrophotometric methods. The most abundant compounds were dicaffeoylquinic acids, representing more than 90% of phenolics in tea infusions. Statistically significant differences were observed for all parameters except for TPC in methanol and aqueous extracts. Both phenolics amount and antioxidant activities were lower after the in vitro digestion of the infusions. However, although phenolics were lost during the simulated digestion, rock tea is still a good source of bioactive compounds with potential applications in the pharmaceutical or nutraceutical industries.


Assuntos
Antioxidantes/análise , Asteraceae/química , Fenóis/análise , Chás de Ervas/análise , Antioxidantes/metabolismo , Cromatografia Líquida de Alta Pressão , Digestão , Suco Gástrico , Humanos , Espectrometria de Massas , Metanol , Compostos Fitoquímicos/análise , Componentes Aéreos da Planta/química
13.
Food Chem Toxicol ; 125: 467-478, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30721739

RESUMO

The presence and accompanying risks of methyleugenol and eugenol in herbal beverages available on the Indonesian market were evaluated. Methyleugenol was detected in 49 out of 114 samples, at levels amounting to 2.6-443.7 µg/g, while 4 samples contained eugenol at 21.4-101.2 µg/g. The EDI resulting from drinking these preparations amounted to 0.1-51.2 µg/kg bw/day and 1.1-3.3 µg/kg bw/day, respectively for samples targeted at adults and children. A BMDL10 value of 22.2 mg/kg bw/day for methyleugenol was defined using literature data and model averaging. MOE values were below 10,000 for 46 samples (40.4%), indicating a priority for risk management when assuming daily lifelong consumption, while the EDI for 4 samples containing eugenol did not exceed the ADI of 2.5 mg/kg bw thus did not raise a concern for human health. Using Haber's rule to correct for less than lifetime exposure, consumption of methyleugenol via these beverages would be of low concern when consumed for less than 2 weeks/year during a lifetime. This conclusion holds for herbal beverages collected by targeted sampling, not for all herbal beverages on the Indonesian market. The study provides data that can support establishment of a maximum permitted level (MPL) for methyleugenol in herbal beverages in Indonesia.


Assuntos
Eugenol/análogos & derivados , Eugenol/análise , Chás de Ervas/análise , Eugenol/toxicidade , Humanos , Indonésia , Magnoliopsida/química , Medição de Risco , Chás de Ervas/toxicidade
14.
J Trace Elem Med Biol ; 52: 111-117, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30732870

RESUMO

In this study twelve trace elements were investigated in herbal tea commercialized in Brazil. Boldo, Chamomile, Mate and Peppermint tea samples were acquired in Brazil local markets and both herbs and their infusions were evaluated. Trace elements were classified in two groups: poorly (Al, As, Ba, Cd, Cr, Fe, Pb and Se) and moderately (Cu, Mn, Ni and Zn) extractable. This patterned showed that even levels above threshold established by Brazilian and MERCOSUR regulations were observed in herbal tea (Cd and Pb in 89% and 78% of mate and peppermint tea samples, respectively), their infusions did not presented toxic levels. The estimative of exposure and dietary intake revealed important values for a daily consumption of a single cup of herbal infusion and an unique composition was also verified for herbal tea samples: although age and origin was unavailable, multivariate analysis classified the samples in four distinct groups.


Assuntos
Comércio , Chás de Ervas/análise , Chás de Ervas/economia , Oligoelementos/análise , Brasil , Espectrometria de Massas , Controle de Qualidade
15.
J Agric Food Chem ; 67(9): 2607-2616, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30758196

RESUMO

Infusion-induced changes in the aroma and key odorants and their odor activity values of Iranian endemic herbal (Gol-Gavzaban) tea obtained from shade-dried violet-blue petals of borage ( Echium amoenum) were studied for the first time. Two hot teas and one cold tea were investigated and coded as 4MN (4 min/98 °C), 16MN (16 min/98 °C), and 24HR (24 h/ambient temperature), respectively. Aromatic extracts of the tea samples were isolated by the liquid-liquid extraction method and analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) for the first time. According to the results of the aroma profiling, a total of 35 common aroma compounds comprising alcohols, acids, volatile phenols, lactones, aldehydes, ketone, pyrroles, and furans were identified and quantified in the tea samples. Indeed, it is worth noting that the aroma profiles of the borage teas were similar. However, the effects of the infusion techniques were clearly different as observed on the content of each individual and total compounds in the samples. The highest mean total concentration was detected in 24HR (266.0 mg/kg), followed by 16MN (247.1 mg/kg) and 4MN (216.1 mg/kg). 1-Penten-3-ol was the principal volatile component in all borage teas. On the basis of the result of the flavor dilution (FD) factors, a combined total of 22 different key odorants was detected. The potential key odorants with regard to FD factors in all samples were prevailingly alcohols, acids, and terpenes. The highest FD factors were observed in 2-hexanol (2048 in 4MN and 24HR; 1024 in 16MN) and 1-penten-3-ol (2048 in 24HR; 1024 in 4MN and 16MN) in samples providing herbal and green notes. Principal component analysis (PCA) showed that the tea samples could clearly be discriminated in terms of their aroma profiles and key odorants. The findings of the current study demonstrate that the tea preparation conditions have a significant impact on the organoleptic quality of borage tea.


Assuntos
Echium/química , Flores/química , Odorantes/análise , Extratos Vegetais/química , Chás de Ervas/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Irã (Geográfico) , Olfatometria/métodos , Temperatura Ambiente , Compostos Orgânicos Voláteis/análise , Água
16.
J Chromatogr A ; 1594: 173-180, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-30770143

RESUMO

A correct botanical identification and analytical quality control of volatile key-markers responsible for aroma and biological activities is necessary to monitor volatile compounds transferred from a plant to the related herbal tea and human intake to guarantee their safe use. This is mainly true for markers limited by regulations or by a recommended maximum amount of consumption per day. GC-MS is the elective technique to analyze volatiles, provided that for aqueous samples (herbal teas) an appropriate sample preparation procedure, and/or a water-compatible GC stationary phases are applied. Solid Phase Micro Extraction (SPME) on-line coupled to GC-MS in a fully automatic approach is here applied to sample and quantify key markers in plant material (headspace) and in the corresponding herbal tea (direct immersion). In parallel, a new generation of GC columns coated with ionic liquid based stationary phases compatible with aqueous samples (Watercol™) was applied to test direct injection of aqueous samples (DAI-GC-FID). The latter approach fully bypasses sample preparation thus speeding up quality control. This study deals with the quantitation of menthol, α- and ß-thujone, estragole, and anethole contained in several plant species commonly used for herbal teas (i.e. peppermint, sage, wormwood, fennel, aniseed) and regulated by International Organizations. The two methods gave comparable results and are characterized by high repeatability, linearity and accuracy, although, as expected, their sensitivity was different because DAI-GC-FID implies injection of the sample as such without analyte concentration as for DI-SPME-GC-MS. For instance, LOD and LOQ of estragole were 0.03 and 0.1 mg L-1 with DI-SPME-GC-MS and 0.1 and 0.8 mg L-1 with DAI-GC-FID. The two methods are fully complementary and their adoption depends on the amount of marker(s) to be quantified.


Assuntos
Análise de Alimentos/métodos , Plantas Medicinais/química , Chás de Ervas/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo
17.
J Sci Food Agric ; 99(7): 3653-3661, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30637751

RESUMO

BACKGROUND: Rooibos represents 10% of the global herbal tea market. Shrinking production areas as a result of climate change necessitate the maximum conversion of plant biomass to product. The present study aimed to determine the potential of rooibos tea processing waste (i.e. fine dust and coarse stems) as potential flavour and herbal tea ingredients, respectively. RESULTS: Hot water extraction of soluble solids (SS) from rooibos dust was optimised and extracts from different production batches (n = 20) were prepared. Their sensory profiles were similar, although less intense than that of infusions of commercial rooibos (n = 20) when diluted to the same SS content. The turbidity and flavonoid content of the diluted extracts was mostly lower (P < 0.05) than that of commercial rooibos. An atypical and negative aroma attribute, 'planky/pencil shavings', was predominant in the stem infusions (n = 20), which contained less SS (P < 0.05) than commercial rooibos. Blends of stem infusion and extract could not effectively mask this negative aroma note (P > 0.05). CONCLUSION: Rooibos dust could be used to produce a rooibos flavour extract, whereas the prominent atypical, negative 'planky/pencil shavings' aroma note of the stems would limit their inclusion in commercial rooibos blends. © 2019 Society of Chemical Industry.


Assuntos
Aspalathus/química , Flavonoides/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Caules de Planta/química , Chás de Ervas/análise , Resíduos/análise , Cor , Poeira/análise , Flavonoides/análise , Humanos , Extratos Vegetais/análise , Paladar
18.
J Sci Food Agric ; 99(3): 1334-1341, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30094845

RESUMO

BACKGROUND: Steam treatment of shredded, fresh C. maculata (honeybush) plant material improves the aroma of this green herbal tea with a slight impact on color and phenolic content, but the effect on storage stability is not known. RESULTS: Steam-treated (60 s before drying) and untreated (control) dried plant material was stored under normal storage conditions in semi-permeable sachets at 25 °C and 60% relative humidity. Reference samples of treated (steamed) and untreated (control) material were stored at 0 °C in impermeable pouches for maximum retention of quality. The stability of the herbal tea was assessed in terms of sensory profile, phenolic composition and color over a storage period of 6 months. Normal storage conditions resulted in a significant (P < 0.05) decrease in green color, especially in steamed samples. Intensities of fruity and sweet-associated aroma attributes increased progressively during storage, while the opposite was observed for vegetal and cereal-like attributes. These changes in the aroma profile were more pronounced in untreated (control) samples. Individual phenolic content remained stable during storage. CONCLUSIONS: Storage of 3 to 6 months may result in a more appealing aroma profile and enhanced product quality, despite loss of green color. © 2018 Society of Chemical Industry.


Assuntos
Cyclopia (Planta)/química , Conservação de Alimentos/métodos , Chás de Ervas/análise , Xantonas/química , Conservação de Alimentos/instrumentação , Armazenamento de Alimentos , Fenóis/química , Controle de Qualidade , Vapor/análise
19.
Food Chem ; 276: 626-635, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30409641

RESUMO

The bitter taste of Cyclopia genistoides infusions is unacceptable to consumers, who are used to the slightly sweet taste of the herbal teas produced from other Cyclopia species. Bitter taste intensities of crude phenolic fractions of a bitter hot water extract of C. genistoides were determined by a trained panel to identify the fraction contributing most to the bitter taste. Fractions, enriched in benzophenones (B), xanthones (X) and flavanones (F), and each tested at their infusion equivalent concentration (IEC) scored 5, 31 and 13 (on a 100-point scale), respectively. Fraction B, containing mostly iriflophenone glucosides, was perceived as not bitter. The major xanthone in fraction X, mangiferin, was significantly (p < 0.05) more bitter than its regio-isomer, isomangiferin, at equal concentration. A mixture of isomangiferin and mangiferin at their IECs was significantly (p < 0.05) less bitter than the mangiferin solution alone, indicating bitter suppression by isomangiferin.


Assuntos
Fabaceae/química , Fenóis/análise , Paladar , Chás de Ervas/análise , Fenóis/química , Estereoisomerismo
20.
Nat Prod Res ; 33(10): 1472-1476, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29262735

RESUMO

Quercetin, luteolin and chrysoeriol were identified from rooibos tea as degranulation inhibitors in rat basophilic leukaemia cells. The degranulation inhibitory activity of chrysoeriol was first discovered in the present study. When quercetin, luteolin and chrysoeriol were mixed in the ratio that occurs in rooibos tea extract, the mixture inhibited antigen- and calcium ionophore-stimulated degranulation to the same degree as that by the whole rooibos tea extract. These findings indicate that these three flavonoids are the key factors underlying the degranulation inhibitory activity of rooibos tea.


Assuntos
Aspalathus/química , Degranulação Celular/efeitos dos fármacos , Chás de Ervas , Animais , Antialérgicos/farmacologia , Basófilos/patologia , Ionóforos de Cálcio/farmacologia , Linhagem Celular Tumoral , Flavonas/farmacologia , Leucemia/patologia , Luteolina/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Quercetina/farmacologia , Ratos , Chás de Ervas/análise
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