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Histogram comparison of mineral and metal concentration in tea leaves and infusions of black tea (BT), blue tea (BT), green tea (GT).
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Chemical compounds within tea (Camellia sinensis) are characterized by an extensive heterogeneity; some of them are crucial for their protective and defensive role in plants, and are closely connected to the benefits that the consumption of tea can provide. This paper is mainly focused on the characterization of polyphenols (secondary metabolites g...
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... analyses were performed in triplicate and the average values of metals with concentration were expressed in µg/L and µg/g. Our results clearly indicate that potassium is the most representative element in both tea leaves and infusions and its concentration increased probably due to infusion process occurring at the timetemperature couples reported in the Material and Method section (Table 2, Figure 4). Other ions e.g., phosphorus, magnesium, calcium, and manganese were similarly abundant with decreasing concentration along the infusion process excluded for phosphorus in black tea (Figure 4). ...
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... results clearly indicate that potassium is the most representative element in both tea leaves and infusions and its concentration increased probably due to infusion process occurring at the timetemperature couples reported in the Material and Method section (Table 2, Figure 4). Other ions e.g., phosphorus, magnesium, calcium, and manganese were similarly abundant with decreasing concentration along the infusion process excluded for phosphorus in black tea (Figure 4). Actually, the chemical elements, namely potassium, sodium, calcium, magnesium, manganese, and phosphorus, were the most abundant ones and their presence in food is considered as healthy and safe for the organism due to their involvement in the main cellular processes. ...
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... is considered an important source on minerals such as manganese, an important element for human health, essential for development, metabolism, and the antioxidant system [38,39]. It seemed to increase as a result of the more intense fermentation process of leaves due to the highest content in black leaves (Figure 4). Manganese is an essential in detoxification of superoxide free radicals because it is contained in the enzyme superoxide dismutase (SOD), catalyzing the dismutation of superoxide radicals into either ordinary molecule oxygen (O2) and hydrogen peroxide (H2O2) [40]. ...
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... manganese can act as a neurotoxin in high quantity and its overexposure by an excessive ingestion or inhalation is associated neurological disorders [41]. Even the concentration of other metals was higher in black tea as a consequence of composition changes induced by fermentation with the exclusion of P, Mg, Ca, Na, Zn, Ba, Sr, Ni, Pb, Co, and Cd whose content was predominant in green tea (Figure 4 and Figure S2). Contrarily, these cited minerals were significantly affected by treatment of leaves. ...
Citations
... Thousands of polyphenols have been identified in higher plants, and several hundred are found in edible plants [3]. Polyphenols are secondary metabolites in plants and are generally involved in defense against UV light or pathogen attacks [4]. In sweet potato, the main polyphenols are caffeoylquinic acids. ...
The storage roots of purple-fleshed sweet potato contain a variety of anthocyanins and polyphenols. Little is known about changes in the total content and composition of anthocyanins and polyphenols in the early growth stages of the root system. In this study, we investigated the changes in anthocyanins and polyphenols in the root system of purple-fleshed sweet potato cultivars at 15, 30, 45, and 60 days after transplant (DAT). Unexpectedly, the highest percentage of acylated anthocyanins in three purple-fleshed cultivars among all growth stages was at 15 DAT. On the other hand, the total polyphenol content in the early growth stages of the root system increased rapidly toward 45 DAT, just before the beginning of storage root enlargement, and then decreased rapidly as the storage roots began to enlarge. These data indicate that the early growth stage of the root system is a critical time. This timing may present a strategy to maximize the accumulation of polyphenols with high antioxidant activity, as well as acylated anthocyanins, to protect against abiotic and biotic stresses.
... For quantitative analysis, triple quadrupole analyzer mass spectrometers, QqQ, operating in multiple reactions monitoring ion mode (MRM), are widely used. MRM-based method that enabled quantifying a wide panel of polyphenols on two different food matrices, tea and chocolate products, with high sensitivity and selectivity (Pinto et al., 2021d(Pinto et al., , 2020b. ...
The high volumes of agri-food waste along the supply chain cause problems, especially by-product-mediated environmental impacts. There is a growing demand for recycling operations to valorize the industrial wastes, especially given that a large proportion of agri-food by-products is organic material further exploitable as a source of energy and bioactive compounds. Our research group has been addressing the characterization of polyphenols from food matrices. Polyphenols are a class of plant secondary metabolites involved in the defense mechanisms against ultraviolet radiation, drastic environmental conditions, insects, and pathogens and contribute to the organoleptic properties of fruits and leaves. Polyphenols are efficient antioxidants and radical scavengers with significant health benefits, such as lowering blood pressure and plasma cholesterol levels thanks to their phenolic structural features. Here, we provide an overview of green strategies and the analytical techniques to extract and detect polyphenols from agri-food by-products. We discuss the applications of untargeted and targeted mass spectrometry approaches to characterize the polyphenol component of chestnut and apple-based wastes. The final goal is to highlight the possibility of recycling such products by extracting bioactive compounds as a source of polyphenols for food, nutraceutical, leather, and cosmeceutical applications.
... Thus, the quality of polyphenols is retained which makes green tea much healthier than black tea in which polyphenol oxidase enzyme converts the polyphenols to other compounds (theaflavin and thearubigin, responsible for black tea color and flavor) resulting in a reduction of polyphenols [3]. Green tea demonstrates several health benefits that are summarized in Figure 2 [20][21][22][23]. The significance of EGCG against cancer has been studied for more than 30 years [16]. ...
... Nowadays, lung cancer accounts for the second highest death globally [23]. The risk factors responsible for this type of disease are (a) tobacco smoking, (b) taking regular dietary supplements, and (c) previous radiation therapy of lung, etc. ...
Cancer is exerting an immense strain on the population and health systems all over the world. Green tea because of its higher simple catechin content (up to 30% on dry weight basis) is greatly popular as an anti-cancer agent which is found to reduce the risks of cancer as well as a range of other diseases. In addition, several in vitro and in vivo studies have shown that green tea possesses copious health benefits like anti-diabetic, anti-obese, anti-inflammatory, neuro-protective, cardio-protective, etc. This review highlights the anti-carcinogenic effects of green tea catechins integrating the recent information to gain a clear concept. Special emphasis was given to the effectiveness of green tea polyphenols (GTP) in the prevention of cancer. Overall, green tea has been found to be effective to reduce the risks of breast cancer, ovarian cancer, liver cancer, colorectal cancer, skin cancer, prostate cancer, oral cancer, etc. However, sufficient information was not found to support that green tea consumption reduces the risk of lung cancer, esophageal cancer, or stomach cancer. The exciting data integrated into this article will increase interest in future researchers to garner more fruitful information on the relevant topics.
... Tea is one of the most popular beverages consumed around the globe and prepared from the leaves of Camellia sinensis. The beneficial effect of tea on human health is primarily due to its high antioxidant activity, which results mainly from the presence of tannins and catechins (epicatechin, epigallocatechin), as well as their derivatives (epicatechin gallate and epigallocatechin gallate) [37][38][39]. Seeds are another product in addition to the leaves of the tea plant; they are the source of vegetable oil, an important plant oil due to its high content of unsaturated fatty acids, especially essential linoleic acid. However, crude camellia seed oil contains some free fatty acids, which must be removed to obtain an oil of acceptable quality. ...
Different plant extracts have the potential to be important sources of phenolic compounds. Their antibacterial, antifungal and antioxidant properties are of interest to researchers due to various possibilities for use in the pharmacy, cosmetic and food industries. Unfortunately, the direct application of phenolics in food is limited because of their hydrophilic nature and low solubility. The review is devoted to the recent advances in the methods of lipophilization of phenolic extracts along with the use of enzymes. The concept of extract modification instead of single compound modification is based on the expected synergistic effect of many phenolic compounds. The main focus is on the phenolic compounds found in fruits, flowers and leaves of different common and underutilized as well as medicinal, folk-medicinal or endemic plants. The compiled papers point to the great interest in the modification of anthocyanins, highly active but often unstable phenolics. Some examples of other flavonoids are also outlined. The possible applications of the lipophilized plant extracts are presented for improving the stability of edible oils, decreasing the content of acrylamide, exhibiting higher color stability in thermal processing and increasing the nutritional value.
... The mineralization program comprised three steps: (1) 5 min from 100 W power to 500 W; (2) 15 min at 800 W; (3) 10 min at 0 W for sample cooling. Measurements were performed as reported in [36], using an Agilent 7700 ICP-MS (Agilent Technologies Santa Clara, CA, USA) equipped with a frequencymatching radio frequency (RF) generator and 3 rd generation Octapole Reaction System (ORS3) operating with helium gas in ORF. ...
Cadmium (Cd) contamination is a severe problem in the environment and produces detrimental effects on crop productivity and quality. Characterization of crop performance at different Cd concentrations is crucial to identify pollution-safe cultivars with low translocation efficiency to aboveground organs to be used for food safety. Here, we estimated germination, survival, growth, photosynthetic pigments, Cd bioaccumulation, among-organs translocation, and ionic balance in six Solanum melongena L. (eggplant) cultivars from the central Mediterranean basin. On two cultivars, we also analyzed expression of genes involved in Cd uptake, i.e., heavy metal ATPases (HMAs) and metal tolerance proteins (MTPs). We found that Cd has a negative effect on all the investigated parameters but with relevant among-cultivar differences. Cd-treated plants showed a decrease in germination rate and survival. Photosynthetic pigments showed opposite trends, i.e., with increasing Cd contents, we observed a decrease in chlorophylls and an increase in carotenoids. The investigated cultivars showed high ability of sequestrating Cd in roots but a low translocation efficiency to the aboveground organs, suggesting a good potential for food safety. The response of plants to Cd was mediated by a different expression of the MTP and HMA gene families. Our study represents the first comprehensive investigation of Cd tolerance in eggplant varieties from the Mediterranean basin and highlights the importance of comparative studies to identify Cd-tolerant cultivars.
... The proposed methodology provides the two or three best transitions for each molecule ensuring greater specificity and selectivity. The transitions were selected, for each analyte, thanks to an in-depth study of the literature and the analysis of fragmentation spectra obtained in our previous studies (26,28,41). ...
This work focused on the extraction, quantification, and characterization of bioactive compounds of Arbutus unedo L. fruits, comparing the results obtained from the different ripening states. Extractions were performed by different methods (such as maceration extraction and ultrasonic extraction) and food grade solvents (aqueous and hydroalcoholic solvents) in each of the all ripening states (four states considered, associated with four different colors, i.e., green, yellow, orange, and red). The presence of (poly)phenols was quantified and characterized, and scavenging activity was determined by the Folin–Ciocâlteu reagent and the DPPH method, respectively. The content of bioactive compounds was characterized by LC-MS/MS, such as multiple reaction monitoring (MRM) mass spectrometry. The results showed that ultrasound-assisted extraction (UAE) performed better than maceration extraction; ethanol–water mixture extracts showed a more positive effect than the use of aqueous extracts regarding the content of total phenolic compounds. Overall, the total phenolic compounds in the EtOH:H2O mixture at a ratio of 7:3 (v:v) were higher than that of the other solvents for both extraction methods. Some bioactive molecules were characterized for the first time in the extracts of A. unedo. The chemical profile of the strawberry tree extracts depended on the degree of fruit ripeness. The results suggest that A. unedo fruits may be of great interest for food and nutraceutical applications.
... The high polyphenolic content in red tea infusions was confirmed by Garbowska et al. [16], who concluded that they contain phenolic compounds at levels up to 199.8 mg/100 mL (which confirms the values determined by the author of the current study for pu-erh tea infusions prepared for longer than 20 min). Many authors argue that the best source of polyphenols are unfermented green teas [5,[44][45][46], although depending on their origin and type of leaves, some contain lower levels of these compounds [9,16,47]. Figure 2 shows the classification of plant phenolics with the indication of their types that are most important in the case of tea leaves and which changes occurring during their processing determine the properties of tea infusions to the greatest extent. ...
... The phenolic compound content in black tea decreased steadily with duration of infusion. Many authors reported changes in phenolics content under the influence of different methods of making infusions [1,12,24,26,46]. Almeida et al. [32] linked this to the change in the temperature of water used for phenolic compound extraction and reported that for green tea leaves, the largest increase in these components occurred when the water temperature dropped from 100 • C to 90 • C. ...
Phenolic compounds are components with proven beneficial effects on the human body, primarily due to their antioxidant activity. In view of the high consumption of tea and the numerous factors that affect the nutritional value of its infusions, the aim of this study was to identify the effects of tea type and duration of leaf extraction with water on the levels of phenolic compounds and other components that determine biological activity (oxalates, Ca, Na, Cu, and Mn). Based on assays, infusions of red tea prepared for 20 min were found to be the best source of phenolics (202.9 mg/100 mL), whereas the lowest level of these compounds was determined in infusions of black tea extracted from leaves for 30 min (46.9 mg/100 mL). The highest degree of increase in polyphenol content (by approx. 50%) was noted in red and green tea infused for between 10 and 20 min, whereas for black tea, polyphenol levels decreased with time. The biological activity of tea infusions appears to be determined to the greatest extent by the interactions between phenolic compounds and oxalates (r = 0.6209), calcium (r = 0.8516), and sodium (0.8045). A daily intake of three to four mugs (1 L) of tea infusions provides the human body the entire amount of phenolics recommended for health reasons (as regards red tea, this is possible at 1/3 of the volume) and covers the daily requirement for manganese, as well as (partially) copper.
... In all teas, except for H. sabdariffa (3.60/600 mL), the iron content was below the LOD. Still, the H. sabdariffa tea iron amount was below than in black tea samples with 7.749 μg/g (equivalent to 4.65 mg/600 mL) and superior to Oolong tea samples (< 0.001 μg/g) and green tea (< 0.001 μg/g) [75]. ...
According to the World Health Organization (WHO), about 80% of people rely on medicinal plants for their primary health needs. Traditional medicine’s principal benefits are their vast population knowledge, low severe adverse effects rate, low cost, and the lack of a medical prescription to use them. While obesity has become a global health issue, an increase in finding cheap and fast ways to lose weight escalates medicinal herbs’ use for this purpose, both in dietary supplements or in teas. At the same time that Brazil aims to expand traditional medicine, reports regarding toxicology and poisoning put natural products’ safety in check. Plants can accumulate heavy metals and metalloids leading to health risks; however, there is a lack of information on that matter, possibly due to a lack of international standardization regarding elemental contamination — this study aimed to determine metal and metalloid concentrations in slimming medicinal plants and their respective teas and evaluate their safety consumption. Metal and metalloid content were determined by inductively coupled plasma optical emission spectrometry (ICP OES). All plants and teas were within the set limits for tolerable upper intake level (UL), provisional tolerable daily maximum intake (PTDMI), and provisional tolerable weekly intake (PTWI). The hazard quotient index (HQ) was above 1 for almost all plants, and the Hibiscus sabdariffa tea regarding aluminum content. The arsenic level was above the Brazilian Pharmacopeia limit in natura plants demonstrating risk in their consumption. Some herbs also presented detection for elements with no safety limits set, such as lead, cadmium, and arsenic, which could mark as a red flag for consumption once their security intake is not precise yet.
... These studies have similarly shown that the order for catechin levels in tea samples is as follows: jasmine/green teas > oolong tea > black tea. This has also been demonstrated by a recent investigation into Chinese tea infusions by Pinto et al. (2020) [23]. Procyanidin B2, which is one of the important dimeric catechins in tea, was detected in all the samples, except for the artichoke tea, while procyanidin A2 was found in only GT3. ...
... These studies have similarly shown that the order for catechin levels in tea samples is as follows: jasmine/green teas > oolong tea > black tea. This has also been demonstrated by a recent investigation into Chinese tea infusions by Pinto et al. (2020) [23]. Procyanidin B2, which is one of the important dimeric catechins in tea, was detected in all the samples, except for the artichoke tea, while procyanidin A2 was found in only GT3. ...
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.
... 36,37 In addition, the developed voltammetric method application has several advantages such as simplicity in sample preparations and analysis, short time of analysis, and the low price of instrumentations compared with other analytical methods. [38][39][40] ...
While platinum electrode shows high reactivity towards adsorption processes, iodine-coated platinum electrode shows remarkable inertness toward these processes. Therefore, iodine-coated platinum electrodes introduce itself to interesting voltammetric applications. This study reports the use of the modified iodine-coated polycrystalline platinum electrode as a voltammetric sensor for gallic acid determination in tea samples. The optimized experimental parameters for the determination of gallic acid were using 0.5M H2SO4 as a supporting electrolyte with a scan rate of 50mV/s. The anodic peak related to gallic acid oxidation was centered at nearly 0.60V. The extended detected linear range for the developed method was between 0.025 and 2.0mM. The anodic current showed excellent linearity with R2=0.9975. The limit of detection; LOD and limit of quantitation; LOQ were 0.022mM and 0.0669mM, respectively, which confirmed the sensitivity of the method. The investigation for the effect of potential interferences from tea components indicated a specific selectivity toward gallic acid with only low interference due to the presence of ascorbic acid, as well as the absence of any electrochemical response toward these components. The proposed method was successfully applied to the analysis of gallic acid in tea samples and the recovery values (90.0-103.25%) support the applying application of the developed method for analysis of gallic acid in tea samples.
