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"Chinese tea"
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Determination of Pb (Lead), Cd (Cadmium), Cr (Chromium), Cu (Copper), and Ni (Nickel) in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry
The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu'er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5%) and recoveries (98.91–101.32%). The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China's Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.
Journal Article
Culture and Sustainability: Evidence from Tea Culture and Corporate Social Responsibility in China
We aim to explore the prerequisites for corporate sustainability from the perspective of non-formal institutions such as culture. Specifically, we seek to investigate whether and how Chinese tea culture influences corporate social responsibility (CSR). We have developed an OLS regression model to examine the relationship between tea culture and CSR, and our findings indicate that local tea culture yields positive effects. To address endogeneity concerns related to this correlation, we employed the local geographic slope as an instrumental variable for tea culture. Subsequent research highlights that the female executive, serving as a mediator variable, represents the primary mechanism influenced by tea culture. Furthermore, our study demonstrates that tea culture exerts a more significant impact on small and medium-sized enterprises as well as state-owned enterprises. Overall, this research contributes to the literature on the determinants of CSR from the vantage point of informal institutions, offering a fresh perspective for exploring the economic ramifications of tea culture for both academia and practitioners. Moreover, it furnishes valuable insights for advancing the sustainable development of enterprises.
Journal Article
Chinese green tea consumption reduces oxidative stress, inflammation and tissues damage in smoke exposed rats
One cause of cigarette smoking is oxidative stress that may alter the cellular antioxidant defense system, induce apoptosis in lung tissue, inflammation and damage in liver, lung, and kidney. It has been shown that Chinese green tea (CGT) (Lung Chen Tea) has higher antioxidant property than black tea. In this paper, we will explore the preventive effect of CGT on cigarette smoke-induced oxidative damage, apoptosis and tissues inflammation in albino rat model.
Albino rats were randomly divided into four groups, i.e. sham air (SA), cigarette smoke (CS), CGT 2% plus SA or plus CS. The exposure to smoking was carried out as a single daily dose (1 cigarette/rat) for a period of 90 days using an electronically controlled smoking machine. Sham control albino rats were exposed to air instead of cigarette smoke. Tissues were collected 24 hr after last CS exposure for histology and all enzyme assays. Apoptosis was evidenced by the fragmentation of DNA using TUNEL assay.
Long-term administration of cigarette smoke altered the cellular antioxidant defense system, induced apoptosis in lung tissue, inflammation and damage in liver, lung, and kidney. All these pathophysiological and biochemical events were significantly improved when the cigarette smoke-exposed albino rats were given CGT infusion as a drink instead of water.
Exposure of albino rat model to cigarette smoke caused oxidative stress, altered the cellular antioxidant defense system, induced apoptosis in lung tissue, inflammation and tissues damage, which could be prevented by supplementation of CGT.
Journal Article
Design of College English Culture Teaching Network Platform under the Background of the Differences between Chinese and Western Tea Culture
Chinese tea culture spread from the east to the west through the Western caravan in the early sixteenth century, and improved by the westerners for countless generations, forming a Western tea culture which is completely different from traditional Chinese tea culture today. Although there are great differences between the two cultures, each has its own irresistible charm. Based on the differences between Chinese and Western tea cultures, this article aims to study the design of a network platform for college English culture teaching under the background of the differences between Chinese and Western tea cultures. It aims to integrate the two into daily teaching so as to truly help students better understand the charm of English. On this basis, students can truly learn college English courses well. At the same time, they can appreciate the charm brought by the impact of the differences between Chinese and Western cultures and form their own positive cognition.
Journal Article
Quantification of Polyphenols and Metals in Chinese Tea Infusions by Mass Spectrometry
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 generally involved in defense against ultraviolet radiation and aggression by pathogens) and metals, extracted from nine Chinese tea samples, by integrating different mass spectrometry methodologies, LC-MS/MS in multiple reaction monitoring (MRM) and inductively coupled plasma mass spectrometry (ICP-MS). Our approach allowed to identify and compare forty polyphenols differently distributed in tea infusions at various fermentation levels. The exploration of polyphenols with nutraceutical potential in tea infusions can widely benefit especially tea-oriented populations. The worldwide consumption of tea requires at the same time a careful monitoring of metals released during the infusion of tea leaves. Metal analysis can provide the identification of many healthy minerals such as potassium, sodium, calcium, magnesium, differently affected by the fermentation of leaves. Our results allowed us: (i) to draw up a polyphenols profile of tea leaves subjected to different fermentation processes; (ii) to identify and quantify metals released from tea leaves during infusion. In this way, we obtained a molecular fingerprint useful for both nutraceutical applications and food control/typization, as well as for frauds detection and counterfeiting.
Journal Article
Comparison of Volatiles in Different Jasmine Tea Grade Samples Using Electronic Nose and Automatic Thermal Desorption-Gas Chromatography-Mass Spectrometry Followed by Multivariate Statistical Analysis
Chinese jasmine tea is a type of flower-scented tea, which is produced by mixing green tea with the Jasminum sambac flower repeatedly. Both the total amount and composition of volatiles absorbed from the Jasminum sambac flower are mostly responsible for its sensory quality grade. This study aims to compare volatile organic compound (VOC) differences in authoritative jasmine tea grade samples. Automatic thermal desorption-gas-chromatography-mass spectrometry (ATD-GC-MS) and electronic nose (E-nose), followed by multivariate data analysis is conducted. Consequently, specific VOCs with a positive or negative correlation to the grades are screened out. Partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) show a satisfactory discriminant effect on rank. It is intriguing to find that the E-nose is good at distinguishing the grade difference caused by VOC concentrations but is deficient in identifying essential aromas that attribute to the unique characteristics of excellent grade jasmine tea.
Journal Article
Determination of 9,10-anthraquinone in tea consumed in Shandong Province of China
In this study, 170 tea samples were investigated for the occurrence of 9,10-anthraquinone (AQ), which was collected from Shandong Province of China in 2018. The contamination levels of AQ were detected by a combination of QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) procedure with gas chromatography tandem mass spectrometry. Under the optimal conditions, the linear range for AQ was from 10 to 200 ng/mL. The recoveries ranged from 95.6% to 101%, with the coefficient of variation less than 3.99%. The limits of detection and quantification for AQ were 0.001 and 0.003 mg/kg, respectively. Owing to the good accuracy, precision, and high sensitivity, the proposed method is suitable for the determination of trace AQ in tea. The results demonstrated that AQ was detected in 67.1% of tea samples, with the average concentration of 0.0160 mg/kg. The contamination levels varied from tea types and sale locations. The individual average values of AQ in green tea, black tea, oolong tea, and pu-erh tea products were 0.0161 mg/kg, 0.0140 mg/kg, < 0.003 mg/kg and 0.0337 mg/kg, respectively. The level of AQ contamination in a descending order was wholesale markets, supermarkets, specialty stores, and production bases. In addition, the influence of different tea-producing areas on AQ contamination level in Shandong Province was investigated. Contamination levels of AQ did not show significant correlation with the producing areas in Shandong. Although a high incidence of AQ contamination was detected in tea samples, the total average value meets the maximum limit of the European Union (0.02 mg/kg).
Journal Article
Brewer’s Spent Grain Biochar: Grinding Method Matters
The present work is based on the principle of biomass waste valorization. Brewer’s spent grains (BSG) come from breweries as by-products. Their huge amount of production on an industrial scale should focus our attention on their valorization, which creates challenges as well as opportunities. One way to valorize BSG by-products is to convert them into biochar, a functional material with multiple potential applications. With an emphasis on sustainable development and the circular economy, in this work, we focused on a comparative study of the different mechanical processes of BSG grinding and their effect on the resulting biochar formed after pyrolysis. Home appliances such as blenders, coffee mills, and mortar and pestles were used for this purpose. FESEM images confirmed the successful creation of five different morphologies from the same BSG under the same pyrolysis conditions. Interestingly, a novel Chinese tea leaf egg-like biochar was also formed. It was found that a series of physical pretreatments of the biomass resulted in the reduced roughness of the biochar surface, i.e., they became smoother, thus negatively affecting the quality of the biochar. XRD revealed that the biomass physical treatments were also reflected in the crystallinity of some biochar. Via a Raman study, we witnessed the effect of mechanical pressure on the biomass for affecting the biochar features through pressure-induced modifications of the biomass’s internal structure. This induced enhanced biochar graphitization. This is a good example of the role of mechanochemistry. DSC revealed the thermochemical transformation of the five samples to be exothermic reactions. This study opens up an interesting possibility for the synthesis of biochar with controlled morphology, crystallinity, degree of graphitization, and heat capacity.
Journal Article