Zirconium­cerium modified polyvinyl alcohol/NaCMC biocomposite film: Synthesis of films through high-speed shear assisted technique and removal fluoride from water.

A new zirconium and cerium-modified polyvinyl alcohol (PVA) sodium carboxymethyl cellulose (NaCMC) film (PVA/CMC-Zr-Ce) was synthesized thru a high-speed shear-assisted method and its adsorption for the removal of fluoride was studied, in which the NaCMC provided -COONa for ion exchange between Na and Zr-Ce, thus the loading amount of Zr-Ce on films was accordingly increased. The morphology and structure of PVA/CMC-Zr-Ce were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Besides, the mechanical properties, water contact angle, and swelling ratio of film were also evaluated. The addition of high-speed shear improved the dispersion of the emulsion system, and PVA/CMC-Zr-Ce film with good adsorption performance and film stability was prepared. While, it was found that the adsorption capacity could reach 67.25 mg/g and equilibrium time could reach 20 min. The adsorption mechanism of PVA/CMC-Zr-Ce revealed that ion exchange between hydroxide and fluoride, electrostatic interactions and complexation were the dominating influencing factors. Based on these findings, it can be concluded that PVA/CMC-Zr-Ce film- synthesized with high-speed shear assistance technique is a promising adsorbent for fluoride removal from water.

Alleviation of fluoride-induced colitis by tea polysaccharides: Insights into the role of Limosilactobacillus vaginalis and butyric acid.

Endemic fluorosis has gained increasing attention as a public health concern, and the escalating risk of colitis resulting from excessive fluoride intake calls for effective mitigation strategies. This study aimed to investigate the potential mechanisms underlying the alleviation of fluoride-induced colitis by Tea polysaccharides (TPS). Under conditions of excessive fluoride intake, significant changes were observed in the gut microbiota of rats, leading to aggravated colitis. However, the intervention of TPS exerted a notable alleviating effect on colitis symptoms. Antibiotic intervention and fecal microbiota transplantation (FMT) experiments provided evidence that TPS-mediated relief of fluoride-induced colitis is mediated through its effects on the gut microbiota. Furthermore, TPS supplementation was found to modulate the structure of gut microbiota, enhance the relative abundance of Limosilactobacillus vaginalis in the gut microbiota, and promote the expression of short-chain fatty acid (SCFAs) receptors in colonic tissue. Notably, L. vaginalis played a significant role in alleviating fluoride-induced colitis and facilitating the absorption of butyric acid in the rat colon. Subsequent butyric acid intervention experiments confirmed its remarkable alleviating effect on fluoride-induced colitis. Overall, these findings provide a potential preventive strategy for fluoride-induced colitis by TPS intervention, which is mediated by L. vaginalis and butyric acid.

Correction: Fang et al. Gandouling Mitigates CuSO4-Induced Heart Injury in Rats. Animals 2022, 12, 2703.

In the original publication [...].

Selenium foliar application contributes to decrease ratio of water-soluble fluoride and improve physio-biochemical components in tea leaves.

The tea plant accumulates elevated levels of fluoride (F) from environmental sources. Drinking tea containing high F levels poses a potential threat to human health. Selenium (Se) was applied by foliar spray to investigate its effects on F accumulation and physiology in tea plant. Foliar application of different forms of Se, i.e., Na2SeO3, Kappa-selenocarrageenan, Selenomethionine and Nanoselenium, reduced F content in tea leaves by 10.17 %-44.28 %, 16.12 %-35.41 %, 22.19 %-45.99 % and 22.24 %-43.82 %, respectively. Foliar spraying Se could increase F accumulation in pectin through increasing pectin content and pectin demethylesterification to bind more F in the cell wall, which decreased the proportion of water-soluble fluoride in tea leaves. Application of Se significantly decreased the contents of chromium (39.6 %-72.0 %), cadmium (48.3 %-84.4 %), lead (2.2 %-44.4 %) and copper (14.1 %-44.6 %) in tea leaves. Foliar spraying various forms of Se dramatically increased the Se content and was efficiently transformed into organic Se accounting for more than 80 % in tea leaves. All Se compounds increased peroxidase activity by 3.3 %-35.5 % and catalase activity by 2.6 %-99.4 %, reduced malondialdehyde content by 5.6 %-37.1 %, and increased the contents of chlorophyll by 0.65 %-31.8 %, carotenoids by 0.24 %-27.1 %, total catechins by 1.6 %-21.0 %, EGCG by 4.4 %-17.6 % and caffeine by 9.1 %-28.6 %. These results indicated that Se application could be served as a potential efficient and safe strategy diminishing the concentration of F in tea leaves.

Zirconium/lanthanum-modified chitosan/polyvinyl alcohol composite adsorbent for rapid removal of fluoride.

A novel and easily separable adsorbent in the shape of a membrane for the rapid removal of fluoride from water was prepared after testing Zr, La and LaZr to modify a chitosan/polyvinyl alcohol composite adsorbent (CS/PVA-Zr, CS/PVA-La, CS/PVA-LA-Zr). The CS/PVA-La-Zr composite adsorbent can remove a large amount of fluoride within 1 min of contact time, and the adsorption equilibrium can be reached within 15 min. The fluoride adsorption behavior of the CS/PVA-La-Zr composite can be described by pseudo-second-order kinetics and Langmuir isotherms models. The morphology and structure of the adsorbents were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adsorption mechanism was studied using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and which showed that ion exchange occurred mainly with hydroxide and fluoride ions. This study showed that an easily operable, low-cost and environmentally friendly CS/PVA-La-Zr has the potential to remove fluoride effectively from drinking water in a short time.

Simultaneous Analysis of 53 Pesticides in Safflower (Carthamus tinctorius L.) by Using LC-MS/MS Coupled with a Modified QuEChERS Technique.

OBJECTIVE: An optimized quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique was investigated and compared with the conventional QuEChERS technique for the simultaneous analysis of fifty-three pesticide residues in safflower using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). METHOD: Graphitic carbon nitride (g-C3N4) consisting of a major amount of carbon and nitrogen with a large surface area was used as a QuEChERS adsorbent instead of graphitized carbon black (GCB) for safflower extraction purification. Validation experiments were performed using spiked pesticide samples, and real samples were analyzed. RESULTS: The linearity of the modified QuEChERS technique was evaluated with high coefficients of determination (R-2) being higher than 0.99. The limits of detection were <10 µg/kg. The spiked recoveries ranged from 70.4% to 97.6% with a relative standard deviation of less than 10.0%. The fifty-three pesticides exhibited negligible matrix effects (<20%). Thiamethoxam, acetamiprid, metolachlor, and difenoconazole were detected in real samples using an established method. CONCLUSION: This work provides a new g-C3N4-based modified QuEChERS technique for multi-pesticide residue analysis in complex food matrices.

1H NMR-based metabolomics combined with chemometrics to detect edible oil adulteration in huajiao (Zanthoxylum bungeanum Maxim.).

Huajiao is a highly valued spice that is susceptible to fraudulent adulteration, particularly the addition of edible oils to increase weight and improve color. Nuclear magnetic resonance (1H NMR) and chemometrics were used to analyze 120 huajiao samples adulterated with different types and levels of edible oils. Using untargeted data and partial least squares-discriminant analysis (PLS-DA), the discrimination rate between types of adulteration reached 100% accuracy, and the R2 value of the prediction set for the level of adulteration using the targeted analysis dataset combined with PLS-regression methods reached 0.99. Triacylglycerols, major components of edible oils, were identified as a marker of adulteration through the variable importance in projection of the PLS-regression. A quantitative method based on the sn-3 triacylglycerol signal was developed that can achieve a detection limit of 0.11%. Testing of 28 market samples showed adulteration with various edible oils, with adulteration rates ranging from 0.96% to 4.41%.

The types of brewing water affect tea infusion flavor by changing the tea mineral dissolution.

The effects of different brewing water samples, including natural drinking water (NDW), pure water (PW), mineral water (MW), distilled water (DW), and tap water (TW) on flavor and quality of green tea infusion were investigated. The results showed the dissolution rate of mineral substances varied greatly depend on the type of water used. Notably, the tea infusion brewed with MW showed the highest taste response and darker but higher brightness in color. Furthermore, the content of volatile compounds was highest in tea infusion brewed with NDW and lowest in tea infusion brewed with MW. The mineral substances content and pH were the main factors affecting volatile compounds in green tea infusion. Thereinto, Ca2+ and Fe3+ remarkably affected the content of alcohols and aldehydes in volatile compounds. These results suggested that water with a neutral pH value and lower mineral substance content is more conducive for brewing green tea.

Hierarchical camellia-like metal-organic frameworks via a bimetal competitive coordination combined with alkaline-assisted strategy for boosting selective fluoride removal from brick tea.

Developing an efficient and easy scale-up adsorbent with excellent fluoride adsorption and selectivity from brick tea is urgently desired. However, the separation of fluoride from tea is particularly challenging due to it contains abundant active compounds. Herein, we report ultrahigh fluoride adsorption from brick tea by a hierarchical camellia-like bimetallic metal-organic frameworks (MOFs). The hierarchical camellia-like Ca2Al1Fu is fabricated via a Ca/Al competitive coordination combined with alkaline-assisted strategy to tailor the morphology and porous structure. Subsequently, we systematically explore how the kinetic, thermodynamic, pH, and coexisting ions parameters employed during fluoride adsorption influence the resulting uptake behavior of Ca2Al1Fu. Further, sensory evaluation of the tea after adsorption is explored to determine the optimal dose that makes Ca2Al1Fu as a practical adsorbent for application. Importantly, the fluoride adsorption capacity of optical CaAlFu with mixed CaAl metals molar ratio of 2:1 is 3.15 and 2.11 times higher than that of pristine CaFu and AlFu, respectively. Theoretical results reveal that the boosting selective fluoride removal can be ascribed to the specific interactions between fluoride and CaAl coordinatively unsaturated bimetallic centers. These results present an effective design strategy for the construction of bimetallic MOFs with hierarchically porous structures for broad prospect in adsorption-based applications.

Aggregating-agent-assisted surface-enhanced Raman spectroscopy-based detection of acrylamide in fried foods: A case study with potato chips.

This study developed a simple, rapid, stable, and reliable technique for acrylamide (AAm) detection through surface-enhanced Raman scattering (SERS) on an AgNPs substrate with an aggregating agent. Specifically, the agglomeration effects of five types of salt solutions (NaCl, KCl, MgCl2, Na2SO4, and MgSO4) were investigated at different concentrations and optimized using an orthogonal experiment. The optimal amounts of the aggregating agent, analytes, and AgNPs were 4, 4, and 12 µL, respectively. A linear relationship (peak area I1449 = 7.4197x + 5984.8, R2 = 0.9971) between the characteristic peak area and AAm concentration was established in the range of 10 to 500 µg/L, and the LOD was 2.5 µg/L. The recoveries and relative standard deviations in the analysis of potato chips samples were 94.67 %-117.50 % and 8.43 %-12.29 %, respectively. The results of the proposed method were consistent with those obtained by LC-MS/MS method. This study demonstrated that SERS has excellent potential for application in the qualitative and quantitative analyses of AAm in fried foods.

Gandouling Mitigates CuSO4-Induced Heart Injury in Rats.

We assessed the protective effects of Gandouling (GDL) on copper sulfate (CuSO4)-induced heart injuries in Sprague−Dawley rats, which were randomly divided into the control, CuSO4, GDL + CuSO4 and penicillamine + CuSO4 groups. The rats received intragastric GDL (400 mg/kg body weight) once per day for 42 consecutive days after 56 days of CuSO4 exposure, and penicillamine was used as a positive control. The levels of plasma inflammatory cytokines (IMA, hFABP, cTn-I and BNP) were determined using the enzyme-linked immunosorbent assay. The histopathological symptoms were evaluated using hematoxylin and eosin staining and transmission electron microscopy. To determine the underlying mechanism, Western blotting was conducted for the detection of the heme oxygenase 1 (HO-1) expression. The results revealed that GDL supplementation alleviated the histopathological symptoms of the rat heart tissue, promoted Cu excretion to attenuate impairment, and significantly decreased inflammatory cytokine levels in the plasma (p < 0.01). In addition, GDL increased the HO-1 expression in the rat hepatic tissue. The protective effect of GDL on the heart was superior to that of penicillamine. Overall, these findings indicate that GDL alleviates hepatic heart injury after a Cu overaccumulation challenge, and GDL supplements can be beneficial for patients with Wilson's disease.

A Rapid Fluorescence Sensor for the Direct Quantification of Rongalite in Foodstuffs.

Rongalite was reported illegally used as a food additive for bleaching purposes and improving the tenderness of foodstuffs, which may endanger public health. At present, rongalite was mostly detected by indirect methods via derivatization or determining its decomposition products. In this study, we developed a new fluorescence sensor for the direct quantification of rongalite based on the principles: (1) dopamine reacts with resorcinol and generates strong fluorophore (azamonardine); (2) rongalite could inhibit the production of fluorophores and then result in lower fluorescence intensity. Hence, the rongalite concentration was inversely proportional to fluorescence intensity of fluorophore. Several crucial reaction conditions of fluorescence sensor were further optimized, such as dopamine and resorcinol concentration, pH values, and reaction time. Under the optimal conditions, the limit of detection of fluorescence sensor was 0.28-0.38 µg/g in vermicelli, wheat and rice powder samples, exhibiting almost 3.5-fold improvement compared to that of lateral flow immunoassay. Moreover, the detection time was substantially decreased to 20 min. The recoveries in spiked samples were 80.7-102.1% with a coefficient of variation of less than 12.6%. In summary, we developed a direct, high throughput, selective and accurate fluorescence sensor that poses a promising application for the rapid detection of rongalite in foodstuffs.

Geographical origin of American ginseng (Panax quinquefolius L.) based on chemical composition combined with chemometric.

American ginseng (Panax quinquefolius L.) is protected by Geographical Indications as harvested roots have different regional characteristics. The aim of this study was to distinguish 95 American ginseng samples from four origins (including America, Canada, Shandong province and the Northeast provinces in China), and to further discriminate samples harvested within the protected designation of origin (PDO) from those harvested in non-PDO regions. Two metabolomic methods were used to acquire qualitative data on the metabolites of American ginseng samples from different origins, namely high-performance liquid chromatography (HPLC) and headspace-gas chromatography-mass spectrometry (HS-GC-MS). There were significant differences in numerous metabolites, including volatile compounds and ginsenosides. American ginsengs from four different regions were discriminated based on 25 volatile compounds and 8 ginsenosides using linear discriminant analysis (LDA), which had a 96.8% accuracy and a 74.7% cross validation rate, and random forest (RF) modeling, which reached 100% accuracy using the training set and 92.9% accuracy using the testing set. The same 33 analytes combined with LDA and RF were compared for discrimination of PDO and non-PDO samples. The 100% accuracy was again obtained using the RF model, but only when using data from both HS-GC-MS and HPLC. The result showed that chemical composition combined with chemometric is effectively and accurately to study the origins of American ginseng.

A comparative UHPLC-Q/TOF-MS-based metabolomics approach coupled with machine learning algorithms to differentiate Keemun black teas from narrow-geographic origins.

Geographic-label is a remarkable feature for Chinese tea products. In this study, the UHPLC-Q/TOF-MS-based metabolomics approach coupled with chemometrics was used to determine the five narrow-geographic origins of Keemun black tea. Thirty-nine differentiated compounds (VIP > 1) were identified, of which eight were quantified. Chemometric analysis revealed that the linear discriminant analysis (LDA) classification accuracy model is 91.7%, with 84.7% cross-validation accuracy. Three machine learning algorithms, namely feedforward neural network (FNN), random forest (RF) and support vector machine (SVM), were introduced to improve the recognition of narrow-geographic origins, the performances of the model were evaluated by confusion matrix, receiver operating characteristic curve (ROC) and area under the curve (AUC). The recognition of RF, SVM and FNN for Keemun black tea from five narrow-geographic origins were 87.5%, 94.44%, and 100%, respectively. Importantly, FNN exhibited an excellent classification effect with 100% accuracy. The results indicate that metabolomics fingerprints coupled with chemometrics can be used to authenticate the narrow-geographic origins of Keemun black teas.

Recent techniques for the authentication of the geographical origin of tea leaves from camellia sinensis: A review.

Tea is one of the most important beverages worldwide, is produced in several distinct geographical regions, and is traded on the global market. The ability to determine the geographical origin of tea products helps to ensure authenticity and traceability. This paper reviews the recent research on authentication of tea using a combination of instrumental and chemometric methods. To determine the production region of a tea sample, instrumental methods based on analyzing isotope and mineral element contents are suitable because they are less affected by tea variety and processing methods. Chemometric analysis has proven to be a valuable method to identify tea. Principal component analysis (PCA) and linear discriminant analysis (LDA) are the most preferred methods for processing large amounts of data obtained through instrumental component analysis.

Efficient isolation and purification of tissue-specific protoplasts from tea plants (Camellia sinensis (L.) O. Kuntze).

BACKGROUND: Plant protoplasts constitute unique single-cell systems that can be subjected to genomic, proteomic, and metabolomic analysis. An effective and sustainable method for preparing protoplasts from tea plants has yet to be established. The protoplasts were osmotically isolated, and the isolation and purification procedures were optimized. Various potential factors affecting protoplast preparation, including enzymatic composition and type, enzymatic hydrolysis duration, mannitol concentration in the enzyme solution, and iodixanol concentration, were evaluated. RESULTS: The optimal conditions were 1.5% (w/v) cellulase and 0.4-0.6% (w/v) macerozyme in a solution containing 0.4 M mannitol, enzymatic hydrolysis over 10 h, and an iodixanol concentration of 65%. The highest protoplast yield was 3.27 × 106 protoplasts g-1 fresh weight. As determined through fluorescein diacetate staining, maximal cell viability was 92.94%. The isolated protoplasts were round and regularly shaped without agglomeration, and they were less than 20 µm in diameter. Differences in preparation, with regard to yield and viability in the tissues (roots, branches, and leaves), cultivars, and cultivation method, were also observed. CONCLUSIONS: In summary, we reported on a simple, efficient method for preparing protoplasts of whole-organ tissue from tea plant. The findings are expected to contribute to the rapid development of tea plant biology.

Use of headspace GC/MS combined with chemometric analysis to identify the geographic origins of black tea.

Some black teas demand high market prices. Black tea samples (306) collected from 10 geographic origins, including China (Guxi, Likou, Jinzipai, Guichi, Dongzhi, Changning, Wuyishan, Shaowu), India (Darjeeling), and Sri Lanka (Kandy), were analyzed using headspace volatilization followed by GC/MS (HS-GC/MS). Forty-eight volatile compounds were identified. The aroma compounds were mainly identified as alcohols, aldehydes, ketones, and esters. Analysis of either full-spectrum data or 22 tea compounds shared among the samples with k-Nearest Neighbor (k-NN) and Random Forest (RF) models discriminated all origins at 100% using KNN and 95% with RF using either data set. The discrimination rates using 2 key aroma compounds (linalool and geraniol) by k-NN were 100% for nine origins, with the rate for Guxi area at 89%, because 3 samples were classified to Jinzipai. The findings support the use of HS-GC/MS combined with chemometrics as a tool to identify the origin of black tea.

The beneficial or detrimental fluoride to gut microbiota depends on its dosages.

Fluoride, widely presented in drinking water and tea, may be detrimental or beneficial to the human health, depending on its dosages ingested. However, the relationship of different dosages of fluoride and gut microbiota is still unclear. In this work, the fermentation model using fecal samples provided by four volunteers was used to evaluate the effects of different dosages of fluoride (1, 2, 10 and 15 mg/L) on the gut microbiota in vitro. The result showed low dosages of fluoride (1 and 2 mg/L) had limited effect on the structure and functional Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of gut microbiota. Furthermore, the low dosage of fluoride could promote the growth of beneficial gut microbiota, including Faecalibacterium and Lactobacillus. Whereas, the high dosage of fluoride (10 and 15 mg/L) significantly changed the composition and functional KEGG pathway of gut microbiota. Moreover, the high dosage of fluoride could also reduce the beneficial gut microbiota, including Faecalibacterium and Phascolarctobacterium, and increase the harmful bacterium including Proteobacteria and Enterobacteriaceae. Both low and high dosages of fluoride showed limited effect on the productions of short-chain fatty acids (SCFAs). Thus, the beneficial or detrimental fluoride to gut microbiota depends on its dosages. The fluoride is expected to serve as a food additive in suitable dosage to improve human health through modulation of the gut microbiota. Moreover, more attention should be paid to toxicity of fluoride with high dosage to gut microbiota.

Metabolics and ionomics responses of tea leaves (Camellia sinensis (L.) O. Kuntze) to fluoride stress.

Tea plant (Camellia sinensis (L.) O. Kuntze) is known to accumulate high concentrations of fluoride (F) in its leaves; however, the underlying mechanism of F accumulation remains unclear. The main objective of this study was to investigate the homeostatic self-defense mechanisms of tea leaves to F supplementation (0, 5, 20, and 50 mgL-1) by metabolomics and ionomics. We identified a total of 96 up-regulated and 40 down-regulated metabolites in tea leaves treated with F. Of these different compounds, minor polypeptides, carbohydrates and amino acids played valuable roles in the F-tolerating mechanism of tea plant. After F treatments, the concentrations of sodium (Na), ferrum (Fe), manganese (Mn), and molybdenum (Mo) were significantly increased in tea leaves, whereas the aluminum (Al) was decreased. These findings suggest that the ionic balance and metabolites are attributable to the development of F tolerance, providing new insight into tea plant adaptation to F stress.

Comparation study on the metabolism destination of neonicotinoid and organophosphate insecticides in tea plant (Camellia sinensis L.).

The absorption, distribution, metabolism and primary risk evaluation data of four neonicotinoids and two organophosphate insecticides in tea plant (Camellia sinensis L.) were compared. 22 neonicotinoid metabolites and 2 organophosphate metabolites were identified. The amount ratio of each neonicotinoid metabolite to its corresponding parent (M/P) was lower than 0.076 in the treated time. The organophosphates (omethoate and methamidophos) increased sharply, with M/Ps as high as 1.111 and 0.612. The risks evaluation of insecticides and their metabolites in treated leaves on day seven showed that the chronic risk was from the lowest 0.0759 (clothianidin) to highest 43.6409% (dimethoate), and the acute risk was highest 0.0370 for all targets. The calculated combined toxicity of leaves treated with acephate reached 1.5 folds in mature, 1.5 folds in tender leaves than no metabolites, and which of dimethoate were 2.1 folds in mature and 3.7 folds in tender leaves.