Differential metabolic profiles of pigment constituents affecting leaf color in different albino tea resources.

Albino tea cultivars with distinct leaf colors have rarely been used to explore the metabolic mechanism of leaf color formation. Carotenoids and chlorophyll are primary pigments affecting leaf color with differential metabolic mechanisms in albino tea resources. TEM analysis showed that in albino stage, much less chloroplasts with abnormal structure were observed in white and yellow tea leaves, which corresponded to the significant reduction of total chlorophyll, Chl a and Chl b, and increase of Chl a/b, resulting in tea leaves to lose their green color.

Study of Laurie tea processor black tea mixing fermentation using the simplex centroid design method.

Background: Broken black tea (BBT) is the most consumed black tea in the world. Laurie tea processor black tea (LTP-BT) is one of the most important categories of BBT. In this study, the fresh leaves of three tea plant cultivars including Golden Peony tea, Yunnandaye, and Fuding Dabai were blended to process LTP-BT using the simplex centroid design.

The unique aroma of ripened Pu-erh tea, Liupao tea and Tietban tea: Associated post-fermentation condition and dominant microorganism with key aroma-active compound.

Dark tea with a unique aroma is a particular type of tea. Post-fermentation is the key manufacturing process that forms a unique aroma, distinguishing dark tea from other types of tea. Different post-fermentation conditions may be the reason for forming unique aromas in various dark teas.

Amino acids and flavonoids analysis reveals quality constituents difference among different albino tea resources.

Albino tea has attracted increased attention due to its unique flavor. To reveal the difference in key metabolites constituting the important quality of different tea resources, amino acids and flavonoids profiles in three albino resources with different degrees of albinism and one normal green variety were comprehensively investigated. K-means analysis revealed 35 amino acids were significantly enriched in 'Jibai', while 3 and 2 were specifically accumulated in 'Huangjinya' and 'Anjibaicha', respectively.

Evaluation of Chongqing Tuo Tea at Different Grades: An Integrated Approach by Artificial and Intelligent Sensory, Non-Volatile, and Volatile Compounds Analysis.

This study aims to investigate the relationship between the grades of Tuo tea and the quality of compounds. A combination of artificial sensory evaluation, intelligent sensory technologies (electronic nose and electronic tongue), gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), chemical-physical analysis, and multivariate statistical analysis were employed to examine the differences among three grades of Tuo tea (SG, 1G, and 2G). The results of artificial sensory evaluation, electronic tongue, and electronic nose revealed that the aroma and taste of different grades of Tuo tea varied greatly.

Effect of blister blight disease caused by on tea quality.

Blister blight, as one of the most threatening and damaging disease worldwide, mainly infects young organs and tissues seriously affecting tea growth and quality. In this study, the spread of pathogen on tea leaves were examined by toluidine blue staining, scanning electron microscope and transmission electron microscope analysis. The composition and abundance of fungal community on leaf tissues were firstly analyzed.

Palladium-Catalyzed Enantioselective Directed C(sp)-H Functionalization Using C-Substituted 8-Aminoquinoline Auxiliaries.

8-Aminoquinoline (AQ) has proven to be a highly effective bidentate directing group for palladium-catalyzed C-H functionalization reactions. However, enantiocontrol of AQ-directed C(sp)-H functionalization reactions has been challenging. Herein, a new protocol is presented for the Pd-catalyzed enantioselective arylation of unactivated β C(sp)-H bonds of alkyl carboxamides with aryl iodides using a C-iodinated 8-aminoquinolines (IQ) auxiliary in conjugation with a BINOL ligand.

Identification and expression analysis of the KNOX genes during organogenesis and stress responseness in Camellia sinensis (L.) O. Kuntze.

Tea plant (Camellia sinensis L.), whose leaves are the major reproductive organs, has been cultivated and consumed widely for its economic and health benefits. The Knotted1-like Homeobox (KNOX) proteins play significant roles in leaf morphology formation and development.

Sensory-directed isolation and identification of an intense salicin-like bitter compound in infected teas with bird's eye spot disease.

Teas infected with bird's eye spot disease generally exhibited a lingering and long-lasting, salicin-like bitter taste, which was unpalatable to consumers. Sensory-directed isolation processes have been performed in this study to investigate the salicin-like bitter compounds in infected teas. Results showed that infected teas were extracted using a 70% methanol aqueous solution to produce methanol extract, which was then further separated by sequential solvent extraction (SSE) to obtain dichloromethane extract, which contained the salicin-like bitter compounds.

Characterization of triterpenoids as possible bitter-tasting compounds in teas infected with bird's eye spot disease.

Tea infected with bird's eye spot disease generally imparts a long-lasting bitter taste, which is unacceptable to most consumers. This study has comprehensively evaluated the taste profiles of infected and healthy teas and investigated their known bitter compounds previously reported in tea. Quantification analyses and calculation of dose-over-threshold (DoT) factors revealed that no obvious difference was visualized in catechins, caffeine, bitter amino acids, and flavonols and their glycosides between infected and healthy tea samples, which was also verified by principal component analysis (PCA) and hierarchical cluster analysis (HCA).

Characteristics of Leaf Spot Disease Caused by Species and the Influence of Infection on Tea Quality.

Leaf spots are the most damaging and common foliar diseases of tea and are caused by several species of fungi. During 2018 to 2020, leaf spot diseases showing different symptoms (large and small spots) were observed in commercial tea plantations in Guizhou and Sichuan provinces of China. The pathogen causing the two different sized leaf spots was identified as the same species () based on morphological characteristics, pathogenicity, and multilocus phylogenetic analysis using the combined ITS, TUB, LSU, and RPB2 gene regions.

Non-volatile metabolites profiling analysis reveals the tea flavor of "Zijuan" in different tea plantations.

Characteristic metabolites including tea polyphenols, amino acids, catechins, caffeine, sugars and anthocyanins were fully analyzed by high performance liquid chromatography (HPLC), gas chromatography tandem mass spectrometry (GC-MS) and ultra-high performance liquid chromatography (UHPLC)-ESI-tandem mass spectrometry (MS/MS), and showed significant differences among Zijuan tea from different plantations in Yunnan province (YN-ZJ), Qijiang (QJ-ZJ) and Ersheng (ES-ZJ) district, China, indicating that Zijuan is significantly influenced by growth conditions. Monosaccharides were the most abundant soluble sugars in YN-ZJ and ES-ZJ, while disaccharides was abundant in QJ-ZJ. d-galactose, d-mannose, d-sorbitol, inositol, d-glucose, d-galacturonic acid and raffinose involved in galactose metabolism were significantly changed (P < 0.

An overview of bitter compounds in foodstuffs: Classifications, evaluation methods for sensory contribution, separation and identification techniques, and mechanism of bitter taste transduction.

The bitter taste is generally considered an undesirable sensory attribute. However, bitter-tasting compounds can significantly affect the overall flavor of many foods and beverages and endow them with various beneficial effects on human health. To better understand the relationship between chemical structure and bitterness, this paper has summarized the bitter compounds in foodstuffs and classified them based on the basic skeletons.

A Rapid Prediction Method of Moisture Content for Green Tea Fixation Based on WOA-Elman.

Fixation is the most critical step in the green tea process. Hence, this study developed a rapid and accurate moisture content detection for the green tea fixation process based on near-infrared spectroscopy and computer vision. Specifically, we created a quantitative moisture content prediction model appropriate for the processing of green tea fixation.

Identification and expression analysis of the ZRT, IRT-like protein (ZIP) gene family in Camellia sinensis (L.) O. Kuntze.

The ZRT, IRT-like protein (ZIP) family plays an essential role in the homeostasis of zinc and iron in plants. However, studies on this family are mainly limited to model species. Here, 12 CsZIPs were identified and investigated the function in Camellia sinensis, being named CsZIP1-12 and divided into four different groups based on phylogenetic relationships.

Streamlined construction of peptide macrocycles palladium-catalyzed intramolecular -arylation in solution and on DNA.

A highly efficient and versatile method for construction of peptide macrocycles palladium-catalyzed intramolecular -arylation of alkyl and aryl thiols with aryl iodides under mild conditions is developed. The method exhibits a broad substrate scope for thiols, aryl iodides and amino acid units. Peptide macrocycles of a wide range of size and composition can be readily assembled in high yield from various easily accessible building blocks.

Characterizing relationship between chemicals and in vitro bioactivities of teas made by six typical processing methods using a single Camellia sinensis cultivar, Meizhan.

Processing method is considered as a major factor that affects biotransformation of phytochemicals in tea and leads to diverse flavor and bioactivity of tea. In the present work, six typical tea manufacturing processings were employed to compare the effect on chemical composition of teas through using leaves of the single tea cultivar - - Camellia sinensis var. Meizhan.

Analysis of taste characteristics and identification of key chemical components of fifteen Chinese yellow tea samples.

In order to explore the taste characteristics and molecular sensory basis of Chinese yellow tea, in this study, quantitative descriptive analysis (QDA) and partial least squares regression (PLSR) were used to analyze the sensory characteristics and chemical components of 15 yellow tea samples from different regions of China. The results showed that: 11 sensory descriptors and their definitions were obtained by QDA, namely, sweet, umami, bitter, sour, astringent, sweet after taste, mellow, neutral, after-taste, thick and tainted taste. The results of variance indicated that there were significant variation in taste sub-attributes of different samples (<0.

A New Species Associated with Brown Blight Disease on .

Brown blight, as the most damaging and common foliar disease of the tea plant () in China, has been recently reported to be caused by different species of the genus . During the years 2016 to 2017, tea plants in commercial tea cultivation areas of Chongqing City that reported significant incidences of brown blight disease were investigated and then analyzed using both morphological characteristics and multilocus phylogenetic analysis. The results showed that at least five species of were identified, including four well-known species (, , , and ) and one novel species (), indicating that there is remarkable species diversity in spp.

Transcriptome and metabolome profiling unveiled mechanisms of tea (Camellia sinensis) quality improvement by moderate drought on pre-harvest shoots.

Conventional wisdom holds that tea (Camellia sinensis) quality can be improved by drought. To clarify the underlying mechanism, a conjoint analysis of transcriptome and metabolome profiling was carried out in tea shoots harvested under different soil water contents (SWCs). Drought had little impact on theanine, catechins and caffeine in field conditions.

Genome-wide identification of the HDAC family proteins and functional characterization of CsHD2C, a HD2-type histone deacetylase gene in tea plant (Camellia sinensis L. O. Kuntze).

The histone deacetylases (HDACs) are involved in growth, development and stress responses in many plants. However, the functions of HDACs in tea plant (Camellia sinensis L. O.

Monitoring the authenticity of pu'er tea via chemometric analysis of multielements and stable isotopes.

Mineral elements and stable isotopes combined with stoichiometric methods were used as a potential tool for first authenticating Chinese tea according to it's production year. A total of 86 mineral elements and stable isotope compositions were determined from the Xiangzhujing Pu'er tea in five different production years using ICP-MS and ICP-OES. On the basis of 78 statistically significant mineral elements and stable isotopes, HCA, PCA, PLS-DA, BP-ANN, and LDA were employed to build authentication models for predicting the Pu'er tea with different production years.

Identification of key odorants responsible for cooked corn-like aroma of green teas made by tea cultivar 'Zhonghuang 1'.

Fangping green tea (FPGT) produced by Zhonghuang 1 (C. sinensis var. sinensis cv.