The variation of acrylamide and 5-hydroxymethylfurfural in tea with different roasting degrees and the effects of tea polyphenols on their formation.

BACKGROUND: Roasting is an essential step in making roasted teas, and its role in producing flavors has been widely studied. However, the variation of potential hazardous compounds during the tea roasting process is still vague. The present study established an effective method based on liquid chromatography-triple quadrupole-tandem mass spectrometry to simultaneously determine the variation of acrylamide (AA), 5-hydroxymethylfurfural (5-HMF), and free amino acids during the tea roasting process. Meanwhile, the effects of several tea polyphenols on the formation of AA and 5-HMF were investigated by a wet-to-dry thermal model reaction. RESULTS: Medium-temperature roasted teas had the highest levels of AA and 5-HMF, with ranges of 0.13-0.15 µg g-1 and 68.72-123.98 µg g-1, respectively. Quantitative results showed that the levels of monosaccharides and amino acids decreased during roasting, which might contribute to the formation of 5-HMF and AA. Meanwhile, the decrease of epigallocatechin gallate (EGCG), epigallocatechin (EGC), and epicatechin (EC) might be related to their inhibitory effects on 5-HMF and AA. Thermal model reaction results showed that EGCG and EC significantly inhibited 5-HMF formation with a decline rate of 33.33% and 72.22%, respectively, mainly by trapping glucose. Gallic acid (GA) also had an inhibitory effect on the formation of AA (decreased by 92.86%) and 5-HMF (44.44%), mainly through impeding the preliminary reaction of asparagine and glucose. CONCLUSION: The roasting temperature determined the levels of AA and 5-HMF in teas. Catechins inhibited the formation of 5-HMF and AA mostly through trapping monosaccharides, while the inhibitory effect of GA was achieved by impeding the reaction. © 2024 Society of Chemical Industry.

Profiling of In Vitro Bioaccessibility and Intestinal Uptake of Flavonoids after Consumption of Commonly Available Green Tea Types.

The aim of this study was to profile the bioaccessibility and intestinal absorption of epicatechins and flavonols in different forms of green tea and its formulation: loose leaf tea, powdered tea, 35% catechins containing GTE, and GTE formulated with green tea-derived polysaccharide and flavonols (CATEPLUS™). The bioaccessibillity and intestinal absorption of epicatechins and flavonols was investigated by using an in vitro digestion model system with Caco-2 cells. The bioaccessibility of total epicatechins in loose leaf tea, powdered tea, GTE, and CATEPLUS™ was 1.27%, 2.30%, 22.05%, and 18.72%, respectively, showing that GTE and CATEPLUS™ had significantly higher bioaccessibility than powdered tea and loose leaf tea. None of the flavonols were detected in powdered tea and loose leaf tea, but the bioaccessibility of the total flavonols in GTE and CATEPLUS™ was 85.74% and 66.98%, respectively. The highest intestinal absorption of epicatechins was found in CATEPLUS™ (171.39 ± 5.39 ng/mg protein) followed by GTE (57.38 ± 9.31), powdered tea (3.60 ± 0.67), and loose leaf tea (2.94 ± 1.03). The results from the study suggest that formulating green tea extracts rich in catechins with second components obtained from green tea processing could enhance the bioavailability of epicatechins.

Antioxidant, Anti-inflammatory, and Chemoprotective Properties of Acacia catechu Heartwood Extracts.

Aqueous extracts of Acacia catechu heartwood are rich source of catechin and epicatechin (gallic acid derivatives), with smaller amounts of flavonoids. Extracts have also been prepared with ethyl acetate, ethanol, and methanol, and the properties of these extracts have been studied and are reviewed. Potent antioxidant activity has been well established in both in vitro and in vivo studies. This antioxidant activity is believed to be responsible for the anti-inflammatory, tissue protectant, antineoplastic, and analgesic activities that have been demonstrated and clearly established in animal and cell culture systems. Furthermore, antihyperglycemic, antidiarrheal, antinociceptive, and antipyretic activities have been demonstrated in animal studies. No adverse effects have been observed in animal or human studies or in cell culture systems. In spite of the fact that Acacia products have been used for many years and the general safety of catechins and epicatechins is well documented, few human studies have ever been conducted on the efficacy or safety of A. catechu heartwood extracts. Several studies have shown that a two-ingredient combination product containing A. catechu extract exhibited no adverse effects when administered daily for up to 12 weeks while exhibiting significant anti-inflammatory activity in subjects with osteoarthritis of the knee. There is a need for additional human clinical studies with regard to efficacy and safety.

Association of dietary flavan-3-ol intakes with plasma phenyl-γ-valerolactones: analysis from the TUDA cohort of healthy older adults.

BACKGROUND: Dietary polyphenols, including flavan-3-ols (F3O), are associated with better health outcomes. The relationship of plasma phenyl-γ-valerolactones (PVLs), the products of colonic bacterial metabolism of F3O, with dietary intakes is unclear. OBJECTIVES: To investigate whether plasma PVLs are associated with self-reported intakes of total F3O and procyanidins+(epi)catechins. DESIGN: We measured 9 PVLs by uHPLC-MS-MS in plasma from adults (>60y) in the Trinity-Ulster-Department of Agriculture (TUDA study (2008 to 2012; n=5186) and a follow-up subset (2014 to 2018) with corresponding dietary data (n=557). Dietary (poly)phenols collected by FFQ were analyzed using Phenol-Explorer. RESULTS: Mean (95% confidence interval [CI]) intakes were estimated as 2283 (2213, 2352) mg/d for total (poly)phenols, 674 (648, 701) for total F3O, and 152 (146, 158) for procyanidins+(epi)catechins. Two PVL metabolites were detected in plasma from the majority of participants, 5-(hydroxyphenyl)-γ-VL-sulfate (PVL1) and 5-(4'-hydroxyphenyl)-γ-VL-3'-glucuronide (PVL2). The 7 other PVLs were detectable only in 1-32% of samples. Self-reported intakes (mg/d) of F3O (r = 0.113, P = 0.017) and procyanidin+(epi)catechin (r = 0.122, P = 0.010) showed statistically significant correlations with the sum of PVL1 and PVL 2 (PVL1+2). With increasing intake quartiles (Q1-Q4), mean (95% CI) PVL1+2 increased; from 28.3 (20.8, 35.9) nmol/L in Q1 to 45.2 (37.2, 53.2) nmol/L in Q4; P = 0.025, for dietary F3O, and from 27.4 (19.1, 35.8) nmol/L in Q1 to 46.5 (38.2, 54.9) nmol/L in Q4; P = 0.020, for procyanidins+(epi)catechins. CONCLUSIONS: Of 9 PVL metabolites investigated, 2 were detected in most samples and were weakly associated with intakes of total F3O and procyanidins+(epi)catechins. Future controlled feeding studies are required to validate plasma PVLs as biomarkers of these dietary polyphenols.

Potential Bioactive Components and Health Promotional Benefits of Tea (Camellia sinensis).

Tea is prepared from the young leaves, buds, stalks of the plant Camellia sinensis. The cultivation process of tea plants and the habit of tea drinking were initiated in China from ancient times. Now, the consumption of tea is very popular throughout the world and it is an integral part of our social culture. Tea contains polyphenolic compounds (catechins and epicatechins), theaflavins, flavonol glycosides, L-theanine, caffeine, theobromine, and volatile organic substances. These bioactive components are responsible for the astringency, flavor, aroma, and taste of the tea as well as its health beneficial effects. Moreover, tea has several medicinal values. The phytochemical components are involved in the prevention and cure of many illnesses like cardiovascular diseases, malignancy, digestive dysfunction, and metabolic disorders like obesity, diabetes. Tea flavonoids show strong antioxidant properties. Caffeine and other methylxanthine regulate the intracellular second messenger levels. Additionally, catechins exhibit anti-inflammatory effects. All these multidimensional actions make some positive attributes in favor of neuroprotection, cardioprotection, and cancer prevention. Various approaches are also taken to use tea ingredients as an adjuvant in cancer therapy. This review emphasizes the importance of bioactive components, and their health promotional activities.KEY TEACHING POINTSOrigin and brief history of tea.Processing steps and characteristics of different types of teas. Bioactive components of teas (green and black tea), their biochemical characteristics and health promotional effects.Role of different bioactive components to control the various physiological and metabolic disorders.Possibilities of use of tea component in cancer therapy.

A targeted and nontargeted metabolomics study on the oral processing of epicatechins from green tea.

Oral processing (OP), referring to the whole process of food digestion in human mouth, has a major influence on food flavor perception. This study focused on the compositional changes of the four green tea epicatechins (viz., EC, EGC, ECG, EGCG) during OP, based on targeted and nontargeted metabolomics. It was found that the four epicatechins were all extensively lost through transformation undergoing OP, among which EC was the most stable one, whereas EGCG the least. EGCG was further revealed to be susceptible to human oral cavity in the simulated OP in vitro. It could be converted physically by precipitating with mucin in saliva, and chemically through hydrolysis and dimerization, mediated mainly by the neutral pH condition. The OP of epicatechins also caused salivary composition changes possibly involving health benefits of green tea. These findings could raise awareness of the interactions between epicatechins, or any other food materials, with human mouth.

Novel Cinnamoylated Flavoalkaloids Identified in Tea with Acetylcholinesterase Inhibition Effect.

3-O-Cinnamoylepicatechin (1) was synthesized along with four flavoalkaloids, (-)-6-(5‴S)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (2), (-)-6-(5‴R)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (3), (-)-8-(5‴S)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (4), and (-)-8-(5‴R)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (5) via esterification of epicatechin followed by phenolic Mannich reaction of 1 with theanine in the presence of heat. The new compounds 1-5 were detected in leaves of three tea cultivars, Fuding-Dabai, Huangjingui, and Zimudan with the help of ultra-performance liquid chromatography hyphenated with a photodiode array detector and electrospray ionization high-resolution mass spectrometry (UPLC-PDA-ESI-HRMS), suggesting that they are naturally occurring in tea leaves. The structures of the novel natural products were characterized by one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) and mass spectroscopy. Compounds 1-5 were then evaluated for their acetylcholinesterase (AChE) inhibitory effect (IC50 = 0.12-1.02 µM). The availability of the synthesized epicatechin derivatives 1-5 via a synthetic route enabled the first unequivocal identification of these derivatives as tea secondary metabolites and made it possible to determine their content in the tea material as well as the diverse bioactivities.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days.

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.

Production and characterization of solid lipid microparticles loaded with guaraná (Paullinia cupana) seed extract.

Guaraná is a native fruit of the Amazon rainforest, which presents high levels of phenolic compounds. However, these bioactive compounds may be unstable in food processing and gastrointestinal conditions. Thus, this work aimed to characterize guaraná seed extract (GSE) followed by microencapsulation using a spray-chilling method and with vegetable fat as carrier, as well as to evaluate the particles. Phenolic-rich GSE was produced using 50% (w/w) hydroalcoholic solution and dehydrated by spray drying and lyophilization. Powdered GSE was characterized in relation to its inhibitory activity on digestive enzymes. Solid lipid microparticles (SLM) were evaluated for the retention of bioactive compounds and the release profile of phenolic compounds in simulated gastrointestinal conditions. Powdered GSE showed anti-obesity potential due to the high inhibitory activity of lipase. Regarding the retention of phenolic compounds, at least 75% were detected after 90 days at 25 °C in SLM. Moreover, SLM loaded with 7.5% GSE released approximately 99% of phenolic compounds in simulated gastrointestinal conditions. These results show the efficiency of spray chilling for protection and release of phenolic compounds from GSE, allowing future application in food.

Alaskan Berry Extracts Promote Dermal Wound Repair Through Modulation of Bioenergetics and Integrin Signaling.

Various wild berry species endemic to Alaska and the circumpolar North that exhibit unique medicinal properties have long been appreciated by indigenous Arctic communities. Traditional use of Alaskan berry preparations in the treatment of skin wounds is recorded but has not been scientifically evaluated. Alaskan wild berries feature diverse phytochemical compositions that contain a variety of bioactive polyphenols exhibiting anti-inflammatory, antioxidant, and antimicrobial properties, making them ideal for wound healing interventions and natural anti-aging cosmeceutical formulations. Given increasing interest in identifying biologically active plant constituents for wound care and cosmeceutical applications, the objective of this study was to screen several wild berry species endemic to Alaska and the circumpolar Artic for wound healing and in the crude, polyphenol-enriched, and further fractionated extracts of: Empetrum nigrum (crowberry), Vaccinium uliginosum (bog blueberry), and V. vitis-idaea (low-bush cranberry or lingonberry). A cell migration assay with human dermal fibroblasts (HDFa) was performed to model promotion of wound closure, revealing that bog blueberry extract most actively promoted migration, whereas divergent effects observed with other berry extracts were related to compositional disparities. Lipopolysaccharide (LPS)-stimulated inflammatory response variables measured in RAW 264.7 macrophages [reactive oxygen species (ROS), NO production, prostaglandin-endoperoxide synthase 2 (COX-2), and inducible nitric oxide synthase (iNOS) expression] were suppressed by most extracts/fractions, but especially bog blueberry and proanthocyanidin (PAC) fractions. Wild berry germplasm contained abundant complex flavonoid structures such as PAC and anthocyanins (ANCs), associated with enhanced repair and inflammatory resolution in these models. Next, underlying mechanisms by which PACs and bioactive metabolites (B2 dimer and epicatechin) could influence wound repair and tissue regeneration were examined. PAC metabolites promoted scratch-wound closure and appeared to exert the highest impacts on early stages of wound healing through stimulating mitochondrial bioenergetics (basal respiration, ATP production, and maximum respiratory capacity) and upregulating expression of important extracellular matrix (ECM) proteins (integrin-ß1 and collagen type I α2 chain). Targeting cellular bioenergetics and integrin-mediated cell-ECM signaling with bioactives from Alaskan wild berries shows considerable therapeutic promise to treat chronic skin wounds and inflammatory skin disorders, as well as more generally to support regenerative healing responses and restore function in a variety of tissue and organ settings after injury or aging.

ß-Cyclodextrin encapsulation elevates antioxidant capacity of tea: A closing chapter on non-epicatechins, atomistic insights from X-ray analysis, DFT calculation and DPPH assay.

Polyphenolic catechins prevalent in tea are powerful antioxidants for therapeutics of various free radical-related diseases. The non-epicatechins are thermally obtained from the naturally abundant epicatechins. In our study series on the structure-antioxidant property relationship of the CD inclusion complexes with tea catechins, this closing chapter presents the ß-CD encapsulation of three non-epicatechins, i.e., (-)-gallocatechin (GC) 1, (-)-catechin gallate (GC) 2, and (-)-gallocatechin gallate (GCG) 3 investigated by means of single-crystal X-ray diffraction, DFT calculation and DPPH radical scavenging activity assay. Detailed structural comparisons of the ß-CD inclusion complexes with both non-epi and epi type catechins reveal that a common host-guest hydrogen bonding scheme and the shielding of catechin OH groups inside the host circular wall play a prime role in flourishing antioxidant capacities in the order of 3 > 2 > 1. This is consistent with the relative thermodynamic stabilities derived from DFT energy minimization.

Effect of fermentation and drying on cocoa polyphenols.

Cocoa seed polyphenols have demonstrated interesting beneficial effects in humans. Most polyphenols contained in fresh seeds are chemically modified during fermentation, drying, and cocoa powder or chocolate production. The improvement of these procedures to obtain a high-polyphenol-content cocoa is highly desirable. To this aim, a field investigation on the effect of fermentation and natural drying on fine flavor National cocoa (cacao Nacional) was performed. Cocoa seeds were fermented for 6 days and, every day, samples were sun-dried and analyzed for polyphenol content and antioxidant power. During the first 2 days of fermentation, Folin-Ciocalteu and FRAP tests evidenced a significant reduction of polyphenol content and antioxidant capacity, respectively. Changes during the following days of fermentation were less significant. Epicatechin, the most studied member of the catechin family, followed a similar pathway of degradation. Data confirmed the high impact of fermentation and drying on cocoa seed polyphenols. Fermentation and drying are, on the one hand, necessary to obtain cocoa flavor and palatability but, on the other hand, are responsible for greatly compromising polyphenol content. To obtain high-polyphenol-content cocoa, the existing fermentation, drying, and manufacturing protocols should be scientifically reviewed to understand and modify the critical steps.