Determination of potential α-glucosidase inhibitors in Jinxuan black tea based on bioaffinity ultrafiltration combined with UHPLC-Q-Exactive-MS.

The search for natural α-glucosidase (α-Glu) inhibitors has gained significant attention in developing novel antidiabetic agents or functional foods. Low-temperature fermented Jinxuan black tea represents a promising source of such bioactive compounds. Sixteen potential α-Glu inhibitors were identified from the tea using 10 kDa affinity ultrafiltration.

Recent Advances of Tannase: Production, Characterization, Purification, and Application in the Tea Industry.

Tannase, as a type of tannin-degrading enzyme, can catalyze the hydrolysis of ester and depside bonds in gallotannins, thereby releasing gallic acid and glucose. Based on this reaction mechanism, Tannase can effectively improve the problems of bitter taste, weak aroma, and tea cheese in tea infusion, and is therefore widely used in the tea industry. However, due to high production costs, difficulties in purification and recovery, and insufficient understanding of Tannase properties, the large-scale application of Tannase is severely limited.

Effect of fermentation temperature on the non-volatile components and hypoglycemic activity of Jinxuan black tea.

Fermentation significantly influences the chemical composition of black tea, yet the effects of different fermentation temperatures on non-volatile components and their hypoglycemic activity are insufficiently studied. This research investigates how varying temperatures (20, 25, and 30°C) affect the bioactive profile and the inhibitory activity of Jinxuan black tea against α-glucosidase and α-amylase. Our results show that lower fermentation temperatures (20°C) lead to elevated levels of key bioactive compounds, including tea polyphenols (9.

Recent Advances Regarding Polyphenol Oxidase in : Extraction, Purification, Characterization, and Application.

Polyphenol oxidase (PPO) is an important metalloenzyme in the tea plant (). However, there has recently been a lack of comprehensive reviews on PPO. In this study, the methods for extracting PPO from , including acetone extraction, buffer extraction, and surfactant extraction, are compared in detail.

Widely targeted metabolomics reveals the effect of different raw materials and drying methods on the quality of instant tea.

Introduction: Instant teas are particularly rich in tea polyphenols and caffeine and have great potential as food ingredients or additives to improve the quality of food and enhance their nutritional and commercial value.

Methods: To determine the relationships between raw material, drying method, and sensory and other quality attributes, instant teas were prepared from three tea varieties, namely black, green and jasmine tea, using two drying methods, namely spray-drying (SD) and freeze-drying (FD).

Results: Both the raw tea material and drying method influenced the quality of the finished instant teas.

Chemical composition and anti-cholesterol activity of tea () flowers from albino cultivars.

Albino tea cultivars are mutant tea plants with altered metabolisms. Current studies focus on the leaves while little is known about the flowers. To evaluate tea flowers from different albino cultivars, the chemical composition and anti-cholesterol activity of tea flowers from three albino cultivars (i.

Adding functional properties to beer with jasmine tea extract.

Hops provide the characteristic bitter taste and attractive aroma to beer; in this study, hops were replaced by jasmine tea extract (JTE) during late-hopping. The addition of JTE improved the beer foam stability 1.52-fold, and increased the polyphenol and organic acid contents.

Impact of tea leaves categories on physicochemical, antioxidant, and sensorial profiles of tea wine.

Introduction: Tea is the main raw material for preparing tea wine.

Methods: In this research, four types of tea wine were prepared using different categories of tea leaves, including green tea, oolong tea, black tea, and dark tea, and the comparative study looking their physicochemical, sensorial, and antioxidant profiles were carried out.

Results: The dynamic changes of total soluble solids, amino acids and ethanol concentrations, and pH were similar in four tea wines.

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.

Mellow and Thick Taste of Pu-Erh Ripe Tea Based on Chemical Properties by Sensory-Directed Flavor Analysis.

The mellow and thick taste is a unique characteristic of pu-erh ripe tea infusion, and it is closely related to the chemical composition of pu-erh ripe tea, which is less studied. This paper clarifies and compares the chemical composition of pu-erh ripe tea to that of the raw materials of sun-dried green tea, and uses membrane separation technology to separate pu-erh ripe tea into the rejection liquid and the filtration liquid. The results show that microorganisms transformed most physicochemical components, except caffeine, during the pile fermentation.

Comparative Analysis of Volatile Compounds in with Different Types Based on HS-SPME-GC-MS.

Tieguanyin (TGY) is one kind of oolong tea that is widely appreciated for its aroma and taste. To study the difference of volatile compounds among different types of TGY and other oolong teas, solid-phase microextraction−gas chromatography−mass spectrometry and chemometrics analysis were conducted in this experiment. Based on variable importance in projection > 1 and aroma character impact > 1, the contents of heptanal (1.

Effects of the Baking Process on the Chemical Composition, Sensory Quality, and Bioactivity of Oolong Tea.

oolong tea (TOT), a semi-oxidized tea originating from Anxi county in China, is categorized into jade TOT, medium-baked TOT, and deep-baked TOT, based on different baking processes. To study the effects of baking, chemical analysis, sensory evaluation, and bioactivity assessments of the three TOTs were conducted. The results indicated that the baking process promoted the formation of colored macromolecules (e.

Effect of Ferrous Ion on Heat-Induced Aroma Deterioration of Green Tea Infusion.

Aroma deterioration is one of the biggest problems in processing tea beverages. The aroma of tea infusion deteriorates fast during heat sterilization and the presence of ferrous ion (Fe) aggravates it. The underlying mechanism remains unveiled.

Zijuan tea- based kombucha: Physicochemical, sensorial, and antioxidant profile.

Zijuan tea is a representative anthocyanin-rich tea cultivar in China. In this study, Zijuan tea was used to produce a novel kombucha beverage (ZTK). The physicochemical, sensory properties, and antioxidant activity of ZTK were compared with that of black tea kombucha (BTK) and green tea kombucha (GTK).

Synergistic enhancement effect of MoO@Ag hybrid nanostructures for boosting selective detection sensitivity.

An ex situ method was used to synthesize noble metals and metal oxide composite materials, due to the selective adsorption properties of metal oxides, the adsorption of different probe molecules by this composite structure had been studied. In the ex situ approach, we use (3-aminopropyl) diethoxy methylsilane (ATES) as a coupling agent which is easy for noble metal nanoparticles deposited on metallic oxide nanomaterials. The Raman scattering (SERS) substrate of 1D MoO nanowires (MoO-NWs) @Ag nanoparticles (Ag-NPs) hybrid surface had been fabricated.

Chemical composition, sensory properties and bioactivities of Castanopsis lamontii buds and mature leaves.

Castanopsis lamontii is used as functional herbal tea in southwest China. Usually, only buds rather than mature leaves are applied. To figure out whether mature leaves were suitable for producing herbal tea, chemical composition, sensory properties and bioactivities of Castanopsis lamontii bud infusion (CLB) and mature leaf infusion (CLM) were investigated.

Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas.

The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins.