Investigation of the effects of white tea on liver fibrosis: An experimental animal model

Liver fibrosis is a common, progressive disease that affects millions of patients worldwide. In this study, it was aimed at investigating the effect of white tea on liver fibrosis in an in-vivo environment by creating an experimental liver fibrosis model on rats. In this study, an experimental liver fibrosis model was created with carbon tetrachloride (CCl4) in Sprague-Dawley rats to investigate the effect of white tea on liver fibrosis. Rats are treated with CCl4 (1 mL/kg) to constitute the liver fibrosis model. White tea was given ad libitum with drinking water. As a result of the study, liver tissue hydroxyproline levels were found to be significantly lower (p = .001) in the white tea group. Histopathologically, it was found that the liver tissue histopathological damage score (LHDS) and fibrosis scoring were significantly lower (p < .001) in the white tea group. However, although it was not statistically significant in the group given white tea, compared with the fibrosis group, it was found that the malondialdehyde (MDA) level in the liver tissues was lower, the glutathione (GSH) level was higher, and the serum alanine aminotransferase (ALT) levels were lower. The study explained the effect of white tea on liver fibrosis and suggested that white tea might be beneficial in reducing the progression of liver fibrosis.

Unlocking the Antioxidant Potential of White Tea and Osmanthus Flower: A Novel Polyphenol Liquid Preparation and Its Impact on KM Mice and Their Offspring

White tea, known for its high polyphenol content, boasts impressive antioxidant properties, but its practical applications remain promising. In this study, we successfully developed a liquid polyphenolic preparation (wtofLPP) using white tea and osmanthus flowers, characterized by its rich antioxidant content and favorable rheological properties. This formulation offers a strong foundation for the creation and utilization of innovative antioxidant-rich food products. Notably, wtofLPP significantly enhanced the activity of certain antioxidant enzymes in both KM mice and their offspring, leading to a reduction in malondialdehyde (MDA) levels, prolonged swimming endurance, and a marked increase in levels of active antioxidant compounds. Furthermore, our study highlights that fatigue stress can impact offspring mice, suggesting that oxidative damage in parents may influence their offspring, potentially affecting their genetic function.

The characteristic of the key aroma-active components in white tea using GC-TOF-MS and GC-olfactometry combined with sensory-directed flavor analysis

BACKGROUND

White tea has become more and more popular with consumers due to its health benefits and unique flavor. However, the key aroma-active compounds of white tea during the aging process are still unclear. Thus, the key aroma-active compounds of white tea during the aging process were investigated using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and gas chromatography-olfactometry (GC-O) combined with sensory-directed flavor analysis.

RESULTS

A total of 127 volatile compounds were identified from white tea samples with different aging years by GC-TOF-MS. Fifty-eight aroma-active compounds were then determined by GC-O, and 19 of them were further selected as the key aroma-active compounds based on modified frequency (MF) and odor activity value (OAV).

CONCLUSION

Aroma recombination and omission testing confirmed that 1-octen-3-ol, linalool, phenethyl alcohol, geraniol, (E)-β-ionone, α-ionone, hexanal, phenylacetaldehyde, nonanal, (E, Z)-(2,6)-nonadienal, safranal, γ-nonalactone and 2-amylfuran were the common key aroma-active compounds to all samples. Cedrol, linalool oxide II and methyl salicylate were confirmed peculiar in new white tea, while β-damascenone and jasmone were peculiar in aged white tea. This work will offer support for further studies on the material basis of flavor formation of white tea. © 2023 Society of Chemical Industry.

Tea's anti-obesity properties, cardiometabolic health-promoting potentials, bioactive compounds, and adverse effects: A review focusing on white and green teas

Tea is one of the most commonly consumed beverages in the world. Morocco, Japan, and China have consumed green tea for centuries. White tea, which is a variety of green teas, is very popular in China and is highly revered for its taste. Presently, both teas are consumed in other countries around the world, even as functional ingredients, and novel research is constantly being conducted in these areas. We provide an update on the health benefits of white and green teas in this review, based on recent research done to present. After a general introduction, we focused on tea's anti-obesity and human health-promoting potential, adverse effects, and new approaches to tea and its bioactive compounds. It has been found that the health benefits of tea are due to its bioactive components, mainly phenolic compounds. Of these, catechins are the most abundant. This beverage (or its extracts) has potential anti-inflammatory and antioxidant properties, which could contribute to body weight control and the improvement of several chronic diseases. However, some studies have mentioned the possibility of toxic effects; therefore, reducing tea consumption is a good idea, especially during the last trimester of pregnancy. Additionally, new evidence will provide insight into the possible effects of tea on the human gut microbiota, and even on the viruses responsible for SARS-CoV-2. A beverage such as this may favor beneficial gut microbes, which may have important implications due to the influence of gut microbiota on human health.

Anti-Obesity Effect of a Tea Mixture Nano-Formulation on Rats Occurs via the Upregulation of AMP-Activated Protein Kinase/Sirtuin-1/Glucose Transporter Type 4 and Peroxisome Proliferator-Activated Receptor Gamma Pathways

White, green, and oolong teas are produced from the tea plant (Camellia sinensis (L.) Kuntze) and are reported to have anti-obesity and hypolipidemic effects. The current study aims to investigate the anti-obesity effects of a tea mixture nano-formulation by targeting the AMPK/Sirt-1/GLUT-4 axis in rats. In vitro lipase and α-amylase inhibition assays were used to determine the active sample, which was then incorporated into a nanoparticle formulation subjected to in vivo anti-obesity testing in rats by measuring the expression level of different genes implicated in adipogenesis and inflammation using qRT-PCR. Moreover, metabolomic analysis was performed for each tea extract using LC/ESI MS/MS coupled to chemometrics in an attempt to find a correlation between the constituents of the extracts and their biological activity. The in vitro pancreatic lipase and α-amylase inhibition assays demonstrated more effective activity in the tea mixture than the standards, orlistat and acarbose, respectively, and each tea alone. Thus, the herbal tea mixture and its nanoparticle formulation were evaluated for their in vivo anti-obesity activity. Intriguingly, the tea mixture significantly decreased the serum levels of glucose and triglycerides and increased the mRNA expression of GLUT-4, P-AMPK, Sirt-1, and PPAR-γ, which induce lipolysis while also decreasing the mRNA expression of TNF-α and ADD1/SREBP-1c, thereby inhibiting the inflammation associated with obesity. Our study suggests that the tea mixture nano-formulation is a promising therapeutic agent in the treatment of obesity and may also be beneficial in other metabolic disorders by targeting the AMPK/Sirt-1/Glut-4 pathway.

A Study on Origin Traceability of White Tea (White Peony) Based on Near-Infrared Spectroscopy and Machine Learning Algorithms

Identifying the geographical origins of white tea is of significance because the quality and price of white tea from different production areas vary largely from different growing environment and climatic conditions. In this study, we used near-infrared spectroscopy (NIRS) with white tea (n = 579) to produce models to discriminate these origins under different conditions. Continuous wavelet transform (CWT), min-max normalization (Minmax), multiplicative scattering correction (MSC) and standard normal variables (SNV) were used to preprocess the original spectra (OS). The approaches of principal component analysis (PCA), linear discriminant analysis (LDA) and successive projection algorithm (SPA) were used for features extraction. Subsequently, identification models of white tea from different provinces of China (DPC), different districts of Fujian Province (DDFP) and authenticity of Fuding white tea (AFWT) were established by K-nearest neighbors (KNN), random forest (RF) and support vector machine (SVM) algorithms. Among the established models, DPC-CWT-LDA-KNN, DDFP-OS-LDA-KNN and AFWT-OS-LDA-KNN have the best performances, with recognition accuracies of 88.97%, 93.88% and 97.96%, respectively; the area under curve (AUC) values were 0.85, 0.93 and 0.98, respectively. The research revealed that NIRS with machine learning algorithms can be an effective tool for the geographical origin traceability of white tea.

Identification, Characterization and Expression Profiling of the RS Gene Family during the Withering Process of White Tea in the Tea Plant (Camellia sinensis) Reveal the Transcriptional Regulation of CsRS8

Raffinose synthetase (RS) is a key enzyme in the process of raffinose (Raf) synthesis and is involved in plant development and stress responses through regulating Raf content. As a sweetener, Raf makes an important contribution to the sweet taste of white tea. However, studies on the identification, analysis and transcriptional regulation of CsRSs (Camellia sinensis RS genes) are still lacking. In this study, nine CsRSs were identified from the tea plant (Camellia sinensis) genome database. The CsRSs were classified into five groups in the phylogenetic tree. Expression level analysis showed that the CsRSs varied in different parts of the tea plant. Transcriptome data showed that CsRSs could respond to persistent drought and cold acclimation. Except for CsRS5 and CsRS9, the expression pattern of all CsRSs increased at 12 h and decreased at 30 h during the withering process of white tea, consistent with the change trend of the Raf content. Furthermore, combining yeast one-hybrid assays with expression analysis, we found that CsDBB could potentially regulate the expression of CsRS8. Our results provide a new perspective for further research into the characterization of CsRS genes and the formation of the white tea flavour.

A Comprehensive Investigation of Macro-Composition and Volatile Compounds in Spring-Picked and Autumn-Picked White Tea

The flavour of white tea can be influenced by the season in which the fresh leaves are picked. In this study, the sensory evaluation results indicated that spring-picked white tea (SPWT) was stronger than autumn-picked white tea (APWT) in terms of the taste of umami, smoothness, astringency, and thickness as well as the aromas of flower and fresh. To explore key factors of sensory differences, a combination of biochemical composition determination, widely targeted volatilomics (WTV) analysis, multivariate statistical analysis, and odour activity value (OAV) analysis was employed. The phytochemical analysis showed that the free amino acid, tea polyphenol, and caffeine contents of SPWTs were significantly higher than those of APWTs, which may explain the higher umami, smoothness, thickness, and astringency scores of SPWTs than those of APWTs. The sabinene, (2E, 4E)-2, 4-octadienal, (-)-cis-rose oxide, caramel furanone, trans-rose oxide, and rose oxide contents were significantly higher in SPWTs than in APWTs, which may result in stronger flowery, fresh, and sweet aromas in SPWTs than in APWTs. Among these, (2E,4E)-2,4-octadienal and (-)-cis-rose oxide can be identified as key volatiles. This study provides an objective and accurate basis for classifying SPWTs and APWTs at the metabolite level.

Metabolomics Combined with Proteomics Provide a Novel Interpretation of the Changes in Flavonoid Glycosides during White Tea Processing

In this study, nonvolatile metabolomics and proteomics were applied to investigate the change mechanism of flavonoid glycoside compounds during withering processing of white tea. With the extension of withering time, the content of the main flavonoid glycoside compounds significantly decreased, and then the flavonoid aglycones and water-soluble saccharides contents increased. However, the change trends of these compounds were inconsistent with the expression pattern of related biosynthesis pathway proteins, indicating that the degradation of flavonoid glycosides might exist in the withering process of white tea. One co-expression network that was highly correlated with variations in the flavonoid glycosides’ component contents during the withering process was identified via WGCNA. Further analysis revealed that the degradation of flavonoid glycosides may be related to the antioxidant action of tea leaves undergoing the withering process. Our results provide a novel characterization of white tea taste formation during processing.

Incorporation of white tea extract in nano-liposomes: optimization, characterization, and stability

BACKGROUND

In the present study, an extraction method affected by sonication intensity (40%, 70% and 100%), sonication time (5, 10 and 15 min) and different solvents (ethanol, methanol and a combination of ethanol/methanol) was optimized to extract the white tea with the greatest polyphenolic compounds using a response surface methodology. To prepare the nano-liposomal vesicles, phospholipids and cholesterol in various proportions (60:0, 40:20, 30:30 and 20:40) were applied based on thin-film hydration and ultrasound method. The nano-capsules enriched in bioactive compounds were examined through particle characteristics, encapsulation efficiency, morphological analysis, thermal properties and Fourier transform infrared spectroscopy.

RESULTS

The observations showed that the extraction yield highly depended on the type of solvent with varying permeability, sonication time and power. The highest total phenolic content (68.38 mg GA g^-1 ) and free radical scavenging activity (77.65%) were observed for the following optimal conditions: 70% for sonication intensity, 15 min for sonication time and methanol as solvent. Characteristics of nanoliposomes within a compositional ratio of lecithin/cholesterol (40:20) and with a zeta potential of -56 ± 0.01 mV, as well as white tea extract (WTE) samples with an average particle diameter of 82.20 ± 0.08, microencapsulation efficiency of 76.5% ± 0.081, polydispersity index of 0.06 ± 0.02 and span value of 0.69 ± 0.03. are used as the optimal formulation for microencapsulation of antioxidant WTE. The results demonstrated an increment in thermal stability of liposomal WTE samples compared to other samples.

CONCLUSION

The findings of the present study indicated that nano-liposomes comprise an effective technology for coating the WTE, as well as to increasing its stability and thermal properties. © 2021 Society of Chemical Industry.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Isolation of N-Ethyl-2-pyrrolidinone-Substituted Flavanols from White Tea Using Centrifugal Countercurrent Chromatography Off-Line ESI-MS Profiling and Semi-Preparative Liquid Chromatography

N-Ethyl-2-pyrrolidinone-substituted flavanols (EPSF) are marker compounds for long-term stored white teas. However, due to their low contents and diasteromeric configuration, EPSF compounds are challenging to isolate. In this study, two representative epimeric EPSF compounds, 5'''R- and 5'''S-epigallocatechin gallate-8-C N-ethyl-2-pyrrolidinone (R-EGCG-cThea and S-EGCG-cThea), were isolated from white tea using centrifugal partition chromatography (CPC). Two different biphasic solvent systems composed of 1. N-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v) and 2. N-hexane-ethyl acetate-acetonitrile-water (0.7:3.0:1.3:5.0, v/v/v/v) were used for independent pre-fractionation experiments; 500 mg in each separation of white tea ethyl acetate partition were fractionated. The suitability of the two solvent systems was pre-evaluated by electrospray mass-spectrometry (ESI-MS/MS) analysis for metabolite distribution and compared to the results of the CPC experimental data using specific metabolite partition ratio K_D values, selectivity factors α, and resolution factors&nbsp;R_S. After size-exclusion and semi-preparative reversed-phase liquid chromatography, 6.4 mg of R-EGCG-cThea and 2.9 mg of S-EGCG-cThea were recovered with purities over 95%. Further bioactivity evaluation showed that R- and S-EGCG-cThea possessed in vitro inhibition effects on α-glucosidase with IC₅₀ of 70.3 and 161.7 μM, respectively.

White Tea Intake Abrogates Markers of Streptozotocin-Induced Prediabetes Oxidative Stress in Rat Lungs'

Prediabetes (PrDM) is a prodromal stage of diabetes mellitus (DM) with an increasing prevalence worldwide. During DM progression, individuals gradually develop complications in various organs. However, lungs are suggested to be affected later than other organs, such as the eyes, heart or brain. In this work, we studied the effects of PrDM on male Wistar rats’ lungs and whether the regular consumption of white tea (WTEA) for 2 months contributes to the improvement of the antioxidant profile of this tissue, namely through improved activity of the first line defense antioxidant enzymes, the total antioxidant capacity and the damages caused in proteins, lipids and histone H2A. Our data shows that PrDM induced a decrease in lung superoxide dismutase and glutathione peroxidase activities and histone H2A levels and an increase in protein nitration and lipid peroxidation. Remarkably, the regular WTEA intake improved lung antioxidant enzymes activity and total antioxidant capacity and re-established the values of protein nitration, lipid peroxidation and histone H2A. Overall, this is the first time that lung is reported as a major target for PrDM. Moreover, it is also the first report showing that WTEA possesses relevant chemical properties against PrDM-induced lung dysfunction.

Effect of white tea consumption on serum leptin, TNF-α and UCP1 gene expression in ovariectomized rats

BACKGROUND

Obesity and dyslipidemia due to estrogen deficiency are among the important health problems in menopausal women. Increasing evidence reports the anti-obesity and anti-hyperlipidemic properties of tea polyphenols. However, the effect of white tea (WT) with high polyphenol content on overweight and lipid profile is uncertain. Here, we aimed to examine the effects of long-term WT consumption on serum leptin, tumor necrosis factor- alpha (TNF-α) and uncoupling protein 1 (UCP1) mRNA gene expression in ovariectomized (OVX) rats.

METHODS

Adult rats were divided into four groups (n = 8): (i) sham, (ii) OVX, (iii) WT and (iv) OVX + WT. WT was given at a dose of 0.5% w/v for 12 weeks. In the study, body weight, serum leptin, TNF, estradiol (E2) levels, lipid profile and UCP1 mRNA gene expression in brown adipose tissue (BAT) were evaluated.

RESULTS

There was a significant increase in body weight of OVX rats, which was decreased following WT consumption. While leptin and E2 levels decreased in the OVX group, TNF levels increased. There was no difference between the NF-kB levels of the groups. In addition, BAT UCP1 mRNA expression was significantly decreased in OVX groups, while WT treatment stimulated UCP1 activity.

CONCLUSION

We explain the stimulatory effect of WT on weight loss mainly by the induction of UCP1 gene-mediated thermogenesis and suppression of inflammation. Therefore, we suggest that prolonged WT consumption may have beneficial effects in limiting excess weight gain caused by estrogen deficiency.

Combination of white tea and peppermint demonstrated synergistic antibacterial and anti-inflammatory activities

BACKGROUND

White tea, considered to be the oldest form of tea, is becoming a popular beverage for its organoleptic characteristics. Peppermint tea, used as a herbal remedy for centuries, is now also very popular throughout the world as herbal tea. What interested us was that in ancient China, peppermint was used in combination with tea as a detoxification or anti-inflammatory agent. However, there are few reports on the combined use of white tea and peppermint. Therefore, this study aims to investigate the antibacterial and anti-inflammatory activities of white tea in combination with peppermint.

RESULTS

A synergistic inhibitory effect against four bacterial strains, especially against Staphylococcus argenteus, was observed in the combination of white tea and peppermint in vitro. In addition, the combined formula demonstrated a stronger anti-inflammatory effect in vivo than either of the two used alone, which was associated with the decrease of the pro-inflammatory cytokines of interleukin-6 (IL-6), interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In a further mechanism study, it was found that white tea and peppermint inhibited the phosphorylation of p-IκB-α and mitogen-activated protein kinase (MAPK) at different degrees. While the enhanced anti-inflammatory effect of the combined formula was associated with the combination of NF-κB down-regulation and p-MAPK inhibition.

CONCLUSION

In our study, it was for the first time shown that when white tea was combined with peppermint, the antibacterial and anti-inflammatory effects were enhanced. The results suggested an effective application of white tea in combination with peppermint as a potential antibacterial and anti-inflammatory functional food. © 2020 Society of Chemical Industry.

Analysis of aroma-active volatiles in an SDE extract of white tea

White tea is a famous Chinese tea that is cooked at boiling point before drinking. The simultaneous distillation-extraction (SDE) was used to collect volatile compounds during tea cooking. The SDE extract was dominated with green, floral, roasted and woody notes, and weak sweet note. There were 32 volatile compounds identified via gas chromatography-mass spectrometry analysis, and 19 of them had strong fragrance based on the gas chromatography-olfactometry analyzed results. Hexanal, 2-hexenal, cis-3-hexen-1-ol, and camphene were the main contributors to the green note. The floral note was mainly contributed by 2-hexanone, benzeneacetaldehyde, trans-linalool oxide, and linalool, and the sweet note was induced by trans-β-damascenone. The roasted note was mainly contributed by 2-pentyl-furan. The woody note was mainly contributed by trans-α-ionone and trans-β-ionone. Four putative reaction pathways, including amino acid degradation, carotene degradation, Maillard reaction, and glycosides hydrolysis, were figured out to explain the generation of aromatic-active volatiles at high temperatures. This study added our knowledge on tea aroma under cooking as well as other thermal treatments.

Identification of Aroma Composition and Key Odorants Contributing to Aroma Characteristics of White Teas

The identification of aroma composition and key odorants contributing to aroma characteristics of white tea is urgently needed, owing to white tea's charming flavors and significant health benefits. In this study, a total of 238 volatile components were identified in the three subtypes of white teas using headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). The multivariate statistical analysis demonstrated that the contents of 103 volatile compounds showed extremely significant differences, of which 44 compounds presented higher contents in Baihaoyinzhen and Baimudan, while the other 59 compounds exhibited higher contents in Shoumei. The sensory evaluation experiment carried out by gas chromatography-olfactometry/mass spectrometry (GC-O/MS) revealed 44 aroma-active compounds, of which 25 compounds were identified, including 9 alcohols, 6 aldehydes, 5 ketones, and 5 other compounds. These odorants mostly presented green, fresh, floral, fruity, or sweet odors. Multivariate analyses of chemical characterization and sensory evaluation results showed that high proportions of alcohols and aldehydes form the basis of green and fresh aroma characteristic of white teas, and phenylethyl alcohol, γ-Nonalactone, trans-β-ionone, trans-linalool oxide (furanoid), α-ionone, and cis-3-hexenyl butyrate were considered as the key odorants accounting for the different aroma characteristics of the three subtypes of white tea. The results will contribute to in-depth understand chemical and sensory markers associated with different subtypes of white tea, and provide a solid foundation for tea aroma quality control and improvement.

Changes in Phenolic Compounds Profiles in Tea Extracts and the Composition of these Phenolic Compounds in Yogurt

BACKGROUND

Green, white, and black tea water extracts are rich in phenolic compounds.

OBJECTIVE

The changes in phenolic compound profiles of green, white, and black tea (GT, WT, & BT respectively) water extracts and their respective yogurt were investigated.

METHODS

Three types of yogurt with tea water extracts were prepared, and the phenolic compound profiles were analyzed using the liquid chromatography-mass spectrometry (LC-MS) method.

RESULTS

The present data found that flavonol glycosides such as kaempferol-3-rutinoside and quercetin-rhamnosylgalactoside or rutinoside were present in WT extract, whereas catechin derivatives such as gallocatechin (GC) and epigallocatechin (EGC) were present in GT extract. Moreover, theaflavin-3-O-gallate was observed in BT extract. Many of the catechin and its derivatives detected in the tea extracts were not identified in the tea yogurt samples. However, new phenolic compounds were present in GT-yogurt (i.e., kaempferol-3-rutinoside and quinic acid conjugate) but absent in GT extract.

CONCLUSION

GT, WT, & BT extracts could be used to enriched-yogurt with phenolic compounds, which may have antioxidant properties.

Challenges in confectionery industry: Development and storage stability of innovative white tea-based candies

The aim of this study was the development of innovative candies formulations accordant with the present trends in the confectionery industry. Steviol glycosides, sorbitol, and agave syrup were used as sucrose alternatives, while agar and pectin were included instead of gelatin for the formulation of vegan candies. Additionally, white tea extract was used as a candy base and source of bioactive compounds. Bioactive quality (total phenolic content, antioxidant capacity, epigallocatechin gallate, and caffeine content) and physicochemical (dry matter, springiness, hardness, color) parameters of candies were monitored during 4 months of storage at 4 and 22 °C. Pectin candies with the highest content of dry matter (79.8%) showed the longest shelf life, while those with agar (52.0% and 66.2%) were the most susceptible to spoilage. Candies prepared with agar were less hard (0.4 and 0.6 N) and with less elastic texture (1.5 and 3.4 mm) and showed the highest stability of physicochemical parameters during storage, while those with pectin were also less hard (0.5 N) but with more elastic texture (10.7 mm) than gelatin candies (3.6 and 4.4 mm; 2.4 and 4.1 N). Although gelatin samples were characterized with the greatest bioactive quality parameters immediately after production, they showed a higher instability of the same parameters during storage compared to the agar and pectin candies. PRACTICAL APPLICATION: According to the consumers' demands for healthier confectionery products, formulations of candies with sucrose alternatives, non-animal hydrocolloids, and natural bioactive compounds were developed. Giving a deeper insight into their physicochemical and bioactive properties, this paper could contribute to confectionery industry in development and optimization of formulations in order to obtain candies with desirable and attractive properties.

Hepatoprotective effect of Raspberry ketone and white tea against acrylamide-induced toxicity in rats

The current investigation was accomplished to evaluate the hepatoprotective effect of White tea and Raspberry Ketone against toxicity induced by acrylamide in rats. Sixty adult male rats were divided randomly into group (I) control; group (II) rats received RK with dose (6 mg/kg/day); Group III: rats received 5 ml of WT extract/kg/day; Group IV rats received AA (5 mg/kg/day); Group V: rats administrated with both AA (5 mg/kg/day) and RK (6 mg/kg/day) and Group VI: rats administrated AA (5 mg/kg/day) and 5 ml of WT extract/kg/day. The biochemical assays exhibited a significant increase in serum levels of Adiponectin, AST, ALT, ALP of the group treated with acrylamide if compared to the control group and an improvement in their levels of groups V and VI. The histopathological and immunohistochemical findings confirm the biochemical observations. In conclusion, the present investigation proved that the supplementation of WT and RK enhanced the liver histology, immunohistochemistry and biochemistry against the oxidative stress induced by acrylamide.

White Peony (Fermented Camellia sinensis) Polyphenols Help Prevent Alcoholic Liver Injury via Antioxidation

White peony is a type of white tea (Camellia sinensis) rich in polyphenols. In this study, polyphenols were extracted from white peony. In vitro experiments showed that white peony polyphenols (WPPs) possess strong free radical scavenging capabilities toward 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Long-term alcohol gavage was used to induce alcoholic liver injury in mice, and relevant indices of liver injury were examined. WPPs effectively reduced the liver indices of mice with liver injury. The serum levels of aspartate aminotransferase (ATS), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglycerides (TG), total cholesterol (TC), blood urea nitrogen (BUN), nitric oxide (NO), and malondialdehyde (MDA) were downregulated, while those of albumin (ALB), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were upregulated. WPPs also reduced the serum levels of interluekin-6 (IL-6), interluekin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) in mice with liver injury. Pathology results showed that WPPs reduced alcohol-induced liver cell damage. Quantitative polymerase chain reaction (qPCR) and western blot results revealed that WPPs upregulated the mRNA and protein expressions of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese superoxide dismutase (Mn-SOD), cupro–zinc superoxide dismutase (Cu/Zn-SOD), and CAT and downregulated iNOS expression in the liver of mice with liver injury. WPPs protected against alcoholic liver injury, and this effect was equivalent to that of silymarin. High-performance liquid chromatography revealed that WPPs mainly contained the polyphenols gallic acid, catechinic acid, and hyperoside, which are critical for exerting preventive effects against alcoholic liver injury. Thus, WPPs are high-quality natural products with liver protective effects.

Neuroprotective and Anti-Amyloid β Effect and Main Chemical Profiles of White Tea: Comparison Against Green, Oolong and Black Tea

White tea (WT) is one of six tea types originally derived from Fujian Province, China. White tea is known for its health-promoting properties. However, the neuroprotective and anti-aggregatory properties of WT against the hallmark toxic Alzheimer's protein, Aβ have not been investigated. In this study, WT, green tea (GT), oolong tea (OT) and black tea (BT) were manufactured using tea leaves from the cultivar Camellia sinensis (Jin Guanyin). The protective effects of these tea extracts were then studied under oxidative stress conditions via t-bhp and H₂O₂ exposure, in addition to Aβ treatment using a PC-12 cell model. Each tea type failed to rescue PC-12 cells from either t-bhp or H₂O₂-mediated toxicity, however each extract exerted significant protection against Aβ-evoked neurotoxicity. Results of the Thioflavin T Kinetic (ThT) and TEM assay showed that Aβ aggregate formation was inhibited by each tea type. Additionally, TEM also supported the different anti-aggregatory effect of WT by modifying Aβ into an amorphous and punctate aggregate morphology. Higher accumulated precedent or potential neuroprotective compounds in WT, including ECG''3Me, 8-C-ascorbyl-EGCG, GABA and Gln, in addition to flavonol or flavone glycosides detected by using UPLC-QTOF-MS and UPLC-QqQ-MS, may contribute to a favourable anti-aggregative and neuroprotective effect of WT against Aβ.

Effect of storage time on antioxidant activity and inhibition on α-Amylase and α-Glucosidase of white tea

White tea is considered as a special kind of tea not only for its simplest process, but also for its endurable storage. However, little studies have been done about the changes of white tea with increasing aging time, including its composition and health‐imparting effects. In the present work, white tea aged 1 year (WT‐1), 3 years (WT‐3), and 5 years (WT‐5) were collected. Their major chemical compounds, antioxidant activities, and inhibitory effects on α‐Amylase and α‐Glucosidase were evaluated. Results showed that white tea of different storage time showed good antioxidant activity in DPPH, ABTS, and FRAP assay, which decreases with the prolongation of storage time. The inhibitory effects on α‐Amylase and α‐Glucosidase which are key enzymes related to type II diabetes in vitro, are also observed in the similar trend. Meanwhile, prolongation of storage time decreased the content of polyphenols, the main bioactive compounds in tea, which may lead to decrease in the activities investigated.

Responses of Different Cancer Cells to White Tea Aqueous Extract

White tea from the eastern Chinese province of Fujian is a unique tea variety. Although the health effects of various teas have been investigated in recent years, most studies focused exclusively on green tea varieties. In order to study effects exerted by white tea from eastern Fujian on the viability of cancer cells, we analyzed its main bioactive ingredients. We also evaluated the antioxidant activity of white tea aqueous extract (WTAE) and employed MTT assay to evaluate effects of WTAE on viabilities of Hela and BEL-7402 cancer cell lines. Apoptosis rate detection was also applied to estimate efficacy of cellular apoptotic induction by WTAE in these two cells types. Results revealed that WTAE exhibited high antioxidant activity and inhibited effectively the proliferation of Hela and BEL-7402 cells. The half maximal inhibitory concentration (IC50) of WTAE for Hela cells (0.05 mg/mL) was lower than that for BEL-7402 cells (0.1 mg/mL). Although WTAE induced apoptosis in both cell lines, pro-apoptotic effects were markedly more apparent in Hela cells. Our study demonstrated that WTAE inhibited proliferation of cancer cells via induction of apoptosis and that Hela cells were more sensitive to WTAE than BEL-7402 cells.

PRACTICAL APPLICATION

The aim of this study is to provide a new approach toward cancer prevention by consuming white tea, the properties of which may also be helpful in formulating novel anticancer therapeutics.

Metabolomics Investigation Reveals That 8-C N-Ethyl-2-pyrrolidinone-Substituted Flavan-3-ols Are Potential Marker Compounds of Stored White Teas

White teas of different stored ages have varied flavor, bioactivity, and commercial value. In this study, a liquid chromatography-mass spectrometry-based metabolomics investigation revealed that there are distinct differences among the compound patterns of Baihaoyinzhen (BHYZ) and Baimudan (BMD) white teas with various storage durations. The levels of flavan-3-ols, procyanidins, theasinensins, theaflavins, flavonol- O-glycosides, flavone- C-glycosides, and most of the amino acids were reduced after long-term (>4 years) storage. More importantly, 8-C N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs), including seven novel compounds discovered in white teas for the first time, were formed from theanine and flavan-3-ols during storage, and their contents were positively correlated with the storage duration. These findings were further confirmed by the linearly increasing formation of EPSFs in reaction solution and BMD white teas stored in an environment-controlled cabinet. In conclusion, EPSFs were detected in white teas for the first time and were discovered as marker compounds and potential indicators for long-term storage of white tea.

Functional Characterization of Salicylic Acid Carboxyl Methyltransferase from Camellia sinensis, Providing the Aroma Compound of Methyl Salicylate during the Withering Process of White Tea

Methyl salicylate (MeSA) is one of the volatile organic compounds (VOCs) that releases floral scent and plays an important role in the sweet flowery aroma of tea. During the withering process for white tea producing, MeSA was generated by salicylic acid carboxyl methyltransferase (SAMT) with salicylic acid (SA), and the specific floral scent was formed. In this study, we first cloned a CsSAMT from tea leaves (GenBank accession no. MG459470) and used Escherichia coli and Saccharomyces cerevisiae to express the recombinant CsSAMT. The enzyme activity in prokaryotic and eukaryotic expression systems was identified, and the protein purification, substrate specificity, pH, and temperature optima were investigated. It was shown that CsSAMT located in the chloroplast, and the gene expression profiles were quite different in tea organs. The obtained results might give a new understanding for tea aroma formation, optimization, and regulation and have great significance for improving the specific quality of white tea.

Green synthesis palladium nanoparticles mediated by white tea (Camellia sinensis) extract with antioxidant, antibacterial, and antiproliferative activities toward the human leukemia (MOLT-4) cell line

Among nanoparticles used for medical applications, palladium nanoparticles (PdNPs) are among the least investigated. This study was undertaken to develop PdNPs by green synthesis using white tea (W.tea; Camellia sinensis) extract to produce the Pd@W.tea NPs. The Pd@W.tea NPs were characterized by UV–vis spectroscopy and X-ray diffractometry, and evaluated with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The Pd@W.tea NPs were spherical (size 6–18 nm) and contained phenols and flavonoids acquired from the W.tea extract. Pd@W.tea NPs has good 1-diphenyl-2-picrylhydrazyl (DPPH), OH, and NO-scavenging properties as well as antibacterial effects toward Staphylococcus epidermidis and Escherichia coli. MTT assay showed that Pd@W.tea NPs (IC₅₀ =0.006 μM) were more antiproliferative toward the human leukemia (MOLT-4) cells than the W.tea extract (IC₅₀ =0.894 μM), doxorubicin (IC₅₀ =2.133 μM), or cisplatin (IC₅₀ =0.013 μM), whereas they were relatively innocuous for normal human fibroblast (HDF-a) cells. The anticancer cell effects of Pd@W.tea NPs are mediated through the induction of apoptosis and G2/M cell-cycle arrest.

Influence of brewing conditions on taste components in Fuding white tea infusions

BACKGROUND

White tea has received increasing attention of late as a result of its sweet taste and health benefits. During the brewing of white tea, many factors may affect the nutritional and sensory quality of the resulting infusions. The present study aimed to investigate the effect of various infusion conditions on the taste components of Fuding white tea, including infusion time, ratio of tea and water, number of brewing steps, and temperature.

RESULTS

Brewing conditions had a strong effect on the taste compound profile and sensory characteristics. The catechin, caffeine, theanine and free amino acid contents generally increased with increasing infusion time and temperature. Conditions comprising an infusion time of 7 min, a brewing temperature of 100 °C, a tea and water ratio of 1:30 or 1:40, and a second brewing step, respectively, were shown to obtain the highest contents of most compounds. Regarding tea sensory evaluation, conditions comprising an infusion time of 3 min, a brewing temperature of 100 °C, a tea and water ratio of 1:50, and a first brewing step, resulted in the highest sensory score for comprehensive behavior of color, aroma and taste.

CONCLUSION

The results of the present study reveal differences in the contents of various taste compounds, including catechins, caffeine, theanine and free amino acids, with respect to different brewing conditions, and sensory scores also varied with brewing conditions. © 2016 Society of Chemical Industry.

The antiplaque efficacy of white tea extract mouthrinse

Objective:

This study was conducted to assess the antiplaque efficacy of a mouthwash containing white tea. It also assessed the antibacterial properties of white tea against Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans (Aa) in vitro.

Materials and Methods:

Forty-five subjects with healthy periodontium were randomly chosen and were divided into three groups and advised to use mouthwashes A, B, and C (Group A, white tea; Group B, distilled water [placebo]; Group C, chlorhexidine) for 4 days. They were advised to refrain from any kind of mechanical oral hygiene techniques. Plaque index (PI) was checked on day 1 and 5. In vitro testing for against Pi, Pg, and Aa against white tea extract was undertaken.

Results:

PI significantly increased from day 1 to day 5 (P < 0.01) in Groups A, B, and C. In inter-group comparison, there was a statistical significant difference between white tea mouthrinse group and placebo group, chlorhexidine group and placebo group and also chlorhexidine group and white tea mouthrinse group. However, chlohexidine showed superior antiplaque activity. In vitro test, white tea showed effective inhibition against all three bacterial strains Pi, Pg, and Aa at 1% concentration.

Conclusion:

White tea mouthrinse potently inhibits plaque formation although not as comparable to chlorhexidine mouthrinse. Hence, for those preferring herbal products, white tea mouthrinse is a good option.

Long-term intake of white tea prevents oxidative damage caused by adriamycin in kidney of rats

BACKGROUND

White tea infusion (Camelia sinensis) has antioxidants properties. The infusion contains polyphenols that have been proposed to induce antioxidant response element (ARE) response via nuclear factor E2-related factor 2 (NRF2). Adriamycin (ADR) has antitumour properties and oxidative effects. Oxidative stress is related to a variety of kidney diseases. Prevention of the oxidative stress through long-term intake of white tea and the study of the molecular mechanisms involved in protection could be of great interest. Rats were given distilled water, 0.015 or 0.045 g of solid white tea extract kg(-1) body weight for 12 months. Animals received an injection of ADR. In kidney, oxidative stress parameters were measured, the expressions of nuclear factor E2-related factor 2 gene (Nrf2), and detoxifying and antioxidants genes were analysed, and the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) were measured.

RESULTS

ADR administration increased oxidative parameters and decreased the antioxidant activity; significantly increased the expression of analysed genes and the activity of CAT and SOD and decreased GR activity. The highest white tea dose protected redox status and inhibited ARE response.

CONCLUSION

Long-term intake of white tea protected kidney against the oxidative stress. ADR activated the ARE response but in animals treated with the highest dose of white tea, this response was inhibited, probably for antioxidant protection. © 2015 Society of Chemical Industry.

Recent Advances in Volatiles of Teas

Volatile compounds are important components of tea aroma, a key attribute of sensory quality. The present review examines the formation of aromatic volatiles of various kinds of teas and factors influencing the formation of tea volatiles, including tea cultivar, growing environment and agronomic practices, processing method and storage of tea. The determination of tea volatiles and the relationship of active-aroma volatiles with the sensory qualities of tea are also discussed in the present paper.

Modelling Extraction of White Tea Polyphenols: The Influence of Temperature and Ethanol Concentration

The optimization of the extraction of natural antioxidants from white tea has fostered intensive research. This study has investigated the effects of ethanol-water mixtures, temperature and time on the extraction of polyphenols and antioxidant components from white tea. The response surface methodology was applied to identify the best extraction conditions. The best conditions to maximize the extraction of total polyphenols were: ethanol, 50%, for 47.5 min. Although the yield of polyphenols was optimal at 65 °C, the maximum antioxidant capacity was achieved with an extraction temperature of 90 °C. This study has identified the optimal conditions for the extraction of tea liquor with the best antioxidant properties. Epigallocatechin gallate, epicatechin gallate, epigallocatechin and epicatechin were extracted from white tea at concentrations up to 29.6 ± 10.6, 5.40 ± 2.09, 5.04 ± 0.20 and 2.48 ± 1.10 mg/100 g.

Occurrence of 15 + 1 EU priority polycyclic aromatic hydrocarbons (PAH) in various types of tea (Camellia sinensis) and herbal infusions

For the analysis of 15 + 1 EU priority PAH in tea and herbal infusions, an online-SPE-LVI-GC-MS method was developed. This method includes sample extraction of the tea and herbal infusions with saponification followed by an automated SPE clean-up step. For brews a liquid-liquid extraction with cyclohexane was performed before an automated SPE clean-up. Gas chromatographic separation was done using an Agilent J&W Select PAH (15 m × 0.15 mm × 0.10 µm) column, which allows the separation of the three benzofluoranthenes as well as triphenylene from chrysene. Method performance criteria such as method linearity, limit of quantitation (LOQ) and repeatability were determined and demonstrated that the method was fit for purpose. The method was used to analyse 15 + 1 EU priority PAH in 91 tea and herbal infusion samples. The levels of PAHs ranged from below 0.5 (LOQ) to 460 µg kg⁻¹, with a median of 4.7 µg kg⁻¹ and a mean of 39 µg kg⁻¹ for BaP, and from below 1.0 (LOQ) to 2700 µg kg⁻¹, with a median of 39 µg kg⁻¹ and a mean of 250 µg kg⁻¹ for total PAH, which were in good agreement with other studies reported in the literature. For the brews prepared under normal house preparation (20 g material in 2 L boiling tap water for 10 min), no total 15 + 1 PAH could be detected above the LOQ. With an extended brewing time of 30 min, a transfer rate between 0.25% and 0.52% could be determined, which results in no exceeding of the maximum limits given by the European Union directive for drinking water (EU Council Directive 98/83/EC).

Study on discrimination of white tea and albino tea based on near-infrared spectroscopy and chemometrics

BACKGROUND

White tea and albino tea have their own nutritional characteristics, but from the appearance they are quite similar to each other. It is not easy to distinguish them with existing analytical tools or by visual inspection. The current study proposed a rapid method to discriminate them based on near-infrared (NIR) spectroscopy associated with supervised pattern recognition methods.

RESULTS

For this purpose, discriminant partial least-squares (DPLS) and discriminant analysis (DA) were employed to build classification models on the basis of a reduced subset of wavenumbers and different pretreatment methods. A completely independent validation set was also used to test the model performance. The results of the DA model showed that with the SNV Karl Norris derivative spectral pre-treatment samples from the two different origins could be 100% correctly discriminated. Similarly, for the DPLS model, the best classification results were obtained with the multiplicative scattering correction (MSC) + first derivative spectral pre-treatments; the accuracy of identification was 98.48% for the calibration set and 100% for the validation set.

CONCLUSION

The overall results demonstrated that NIR spectroscopy with pattern recognition could be successfully applied to discriminate white tea and albino tea quickly and non-destructively without the need for various analytical determinations.

White tea as a promising antioxidant medium additive for sperm storage at room temperature: a comparative study with green tea

Storage of sperm under refrigeration reduces its viability, due to oxidative unbalance. Unfermented teas present high levels of catechin derivatives, known to reduce oxidative stress. This study investigated the effect of white tea (WTEA) on epididymal spermatozoa survival at room temperature (RT), using green tea (GTEA) for comparative purposes. The chemical profiles of WTEA and GTEA aqueous extracts were evaluated by (1)H NMR. (-)-Epigallocatechin-3-gallate was the most abundant catechin, being twice as abundant in WTEA extract. The antioxidant power of storage media was evaluated. Spermatozoa antioxidant potential, lipid peroxidation, and viability were assessed. The media antioxidant potential increased the most with WTEA supplementation, which was concomitant with the highest increase in sperm antioxidant potential and lipid peroxidation decrease. WTEA supplementation restored spermatozoa viability to values similar to those obtained at collection time. These findings provide evidence that WTEA extract is an excellent media additive for RT sperm storage, to facilitate transport and avoid the deleterious effects of refrigeration.