Effect Of Green Tea Extract Research Articles

Evaluation of the effects of green tea extract as a dietary supplement in sheep on gas production, volatile fatty acids, and digestibility

Evaluation of the effects of green tea extract as a dietary supplement in sheep on gas production, volatile fatty acids, and digestibility

The Effect of Green Tea Extract on Pulmonary Inflammation in Nanoparticles-Exposed Mice.

Titanium dioxide nanoparticles (TiO2 NPs) are air pollutants that exacerbate chronic respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD) However, little is known about the mechanism underlying the antipollutant effects of green tea extract (GTE). This study evaluates the efficacy and mechanism of GTE on lung inflammation and fibrosis in mice exposed to TiO2 NPs. The TiO2 NPs model is induced by having mice inhale TiO2 NPs, while controls receive an equivalent volume of saline. Treatment with oral GTE is initiated after TiO2 NPs inhalation and is given once daily for 4 weeks. Airway resistance and pulmonary inflammation are increased in mice exposed to TiO2 NPs. GTE treatment reduces the airway inflammation and airway resistance, and attenuates the pathological changes including lung fibrosis compared to the mice exposed to TiO2 NPs. With GTE, there are no significant increases in cytokines and immunoglobulin E (IgE) in mice exposed to TiO2 NPs. GTE inhibits matrix metalloproteinases (MMPs) and apoptotic factors induced by TiO2 NPs exposure, and these protective effects of GTE are closely related to the mitogen-activated protein kinase (MAPK) signaling pathway. GTE modulates pulmonary inflammation in mice exposed to air pollutants, suggesting that GTE may be beneficial in respiratory diseases exacerbated by such pollutants.

Effects of Green Tea Extract Epigallocatechin-3-Gallate on Oral Diseases: A Narrative Review.

Oral diseases are among the most prevalent diseases globally. Accumulating new evidence suggests considerable benefits of epigallocatechin-3-gallate (EGCG) for oral health. This review aims to explore the role and application of EGCG in main oral diseases. This narrative review thoroughly examines and summarizes the most recent literature available in scientific databases (PubMed, Web of Science, Scopus, and Google Scholar) reporting advances in the role and application of EGCG within the dental field. The major keywords used included "EGCG", "green tea extract", "oral health", "caries", "pulpitis", "periapical disease", "periodontal disease", "oral mucosa", "salivary gland", and "oral cancer". EGCG prevents and manages various oral diseases through its antibacterial, anti-inflammatory, antioxidant, and antitumor properties. Compared to traditional treatments, EGCG generally exhibits lower tissue irritation and positive synergistic effects when combined with other therapies. Novel delivery systems or chemical modifications can significantly enhance EGCG's bioavailability, prolong its action, and reduce toxicity, which are current hotspots in developing new materials. this review provides an exhaustive overview of the biological activities of EGCG to major oral diseases, alongside an exploration of applications and limitations, which serves as a reference for preventing and managing oral ailments.

Green tea extracts rich in epicatechins inducing aggregation and inhibiting absorption of amine surface functionalized polystyrene microplastics in vitro mimick system

The current study aimed to investigate the effect of green tea extracts (GTEs) containing 35 % epicatechins on the bioaccessibility of amine surface functionalized polystyrene microplastics (APSMPs), the cellular integrity of intestinal membrane, intestinal absorption, microstructural changes, and aggregation of APSMPs using in vitro digestion with a Caco-2 cell system. The bioaccessibility of APSMPs with GTEs in the ratio of 1:1, 1:2, and 1:5 was observed to be 12.31 ± 0.14, 3.18 ± 0.09, and 1.79 ± 0.16 %, respectively. The trans-epithelial electrical resistances (TEER) value was enhanced while the intestinal transport of APSMPs significantly was decreased by the co-treatment of GTEs. The average particle size of APSMPs treated with GTEs after in vitro digestion became larger in a GTEs dose-dependent manner. The zeta potential value of -12.15 mV exhibited by the APSMPs with GTEs at a 1:2 (v/v) ratio indicates a substantial interparticle agglomeration, implying that APSMPs strongly were bound to GTEs during digestion. Particularly, Epigallocatechin gallate (EGCG) from GTEs treated with APSMPs mostly decreased during digestion, indicating that EGCG was the main component bound to APSMPs. Results from the current study suggest that GTEs could make APSMPs insoluble by aggregation due to a charge difference between APSMPs and the bioactive components present in GTEs.

Green tea extract suppresses airway inflammation via oxidative stress-driven MAPKs/MMP-9 signaling in asthmatic mice and human airway epithelial cells.

The anti-inflammatory effect of green tea extract (GTE) has been confirmed in asthmatic mice, however, the pharmacological mechanism is not fully elucidated. To investigate the therapeutic efficacy of GTE in asthma and identify specific pathways, murine model of allergic asthma was established by ovalbumin (OVA) sensitization and the challenge for 4 weeks, with oral treatment using GTE and dexamethasone (DEX). Inflammatory cell counts, cytokines, OVA-specific IgE, airway hyperreactivity, and antioxidant markers in the lung were evaluated. Also, pulmonary histopathological analysis and western blotting were performed. In vitro, we established the model by stimulating the human airway epithelial cell line NCI-H292 using lipopolysaccharide, and treating with GTE and mitogen-activated protein kinases (MAPKs) inhibitors. The GTE100 and GTE400 groups showed a decrease in airway hyperresponsiveness and the number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) compared to the OVA group. GTE treatment also reduced interleukin (IL)-13, IL-5, and IL-4 levels in the BALF, and OVA-specific immunoglobulin E levels in the serum compared to those in the OVA group. GTE treatment decreased OVA-induced mucus secretion and airway inflammation. In addition, GTE suppressed the oxidative stress, and phosphorylation of MAPKs, which generally occurs after exposure to OVA. GTE administration also reduced matrix metalloproteinase-9 activity and protein levels. GTE effectively inhibited asthmatic respiratory inflammation and mucus hyperproduction induced by OVA inhalation. These results suggest that GTE has the potential to be used for the treatment of asthma.

Synergistic Renoprotective Effects of Green Tea Extract and Gemigliptin against Tacrolimus-Induced Nephrotoxicity in Mice

Synergistic Renoprotective Effects of Green Tea Extract and Gemigliptin against Tacrolimus-Induced Nephrotoxicity in Mice

Characterization of the intestinal transport mechanism of polystyrene microplastics (MPs) and the potential inhibitory effect of green tea extracts on MPs intestinal absorption

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 μm, of amine-modified MPs compared to either larger size (1 μm diameter, or carboxylate-MPs (0.2 and 1 μm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.

Pleiotropic effects of trisomy and pharmacologic modulation on structural, functional, molecular, and genetic systems in a Down syndrome mouse model.

Down syndrome (DS) is characterized by skeletal and brain structural malformations, cognitive impairment, altered hippocampal metabolite concentration and gene expression imbalance. These alterations were usually investigated separately, and the potential rescuing effects of green tea extracts enriched in epigallocatechin-3-gallate (GTE-EGCG) provided disparate results due to different experimental conditions. We overcame these limitations by conducting the first longitudinal controlled experiment evaluating genotype and GTE-EGCG prenatal chronic treatment effects before and after treatment discontinuation. Our findings revealed that the Ts65Dn mouse model reflected the pleiotropic nature of DS, exhibiting brachycephalic skull, ventriculomegaly, neurodevelopmental delay, hyperactivity, and impaired memory robustness with altered hippocampal metabolite concentration and gene expression. GTE-EGCG treatment modulated most systems simultaneously but did not rescue DS phenotypes. On the contrary, the treatment exacerbated trisomic phenotypes including body weight, tibia microarchitecture, neurodevelopment, adult cognition, and metabolite concentration, not supporting the therapeutic use of GTE-EGCG as a prenatal chronic treatment. Our results highlight the importance of longitudinal experiments assessing the co-modulation of multiple systems throughout development when characterizing preclinical models in complex disorders and evaluating the pleiotropic effects and general safety of pharmacological treatments.

Pleiotropic effects of trisomy and pharmacologic modulation on structural, functional, molecular, and genetic systems in a Down syndrome mouse model

Down syndrome (DS) is characterized by skeletal and brain structural malformations, cognitive impairment, altered hippocampal metabolite concentration and gene expression imbalance. These alterations were usually investigated separately, and the potential rescuing effects of green tea extracts enriched in epigallocatechin-3-gallate (GTE-EGCG) provided disparate results due to different experimental conditions. We overcame these limitations by conducting the first longitudinal controlled experiment evaluating genotype and GTE-EGCG prenatal chronic treatment effects before and after treatment discontinuation. Our findings revealed that the Ts65Dn mouse model reflected the pleiotropic nature of DS, exhibiting brachycephalic skull, ventriculomegaly, neurodevelopmental delay, hyperactivity, and impaired memory robustness with altered hippocampal metabolite concentration and gene expression. GTE-EGCG treatment modulated most systems simultaneously but did not rescue DS phenotypes. On the contrary, the treatment exacerbated trisomic phenotypes including body weight, tibia microarchitecture, neurodevelopment, adult cognition, and metabolite concentration, not supporting the therapeutic use of GTE-EGCG as a prenatal chronic treatment. Our results highlight the importance of longitudinal experiments assessing the co-modulation of multiple systems throughout development when characterizing preclinical models in complex disorders and evaluating the pleiotropic effects and general safety of pharmacological treatments.

Neuroprotective effect of green tea extract (-)-epigallocatechin-3-gallate in a preformed fibril-induced mouse model of Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra (SN). The main bioactive component of green tea polyphenols (-)-epigallocatechin-3-gallate (EGCG) exerts protective effects against diseases such as neurodegenerative diseases and cancer. Therefore, this study investigated the effect of EGCG on the amelioration of neural damage in a chronic PD mouse model induced by α-synuclein preformed fibrils (α-syn-PFFs). A total of 20 C57BL/6J female mice were randomly divided into 3 groups: control group (saline, n = 6), model group (PFFs, n = 7), and prevention group (EGCG+PFFs, n = 7). A chronic PD mouse model was obtained by the administration of α-syn-PFFs by stereotaxic localization in the striatum. Behavioral tests were performed to evaluate PD-related anxiety-like behavior and motor impairments in the long-term PD progression. Tyrosine hydroxylase (TH) immuno-positive neurons and Ser129-phosphorylated α-syn (p-α-syn) were identified by immunohistochemistry. Pro-inflammatory and anti-inflammatory cytokines were measured by real-time quantitative PCR. EGCG pretreatment reduced anxiety-like behavior and motor impairments as revealed by the long-term behavioral test (2 weeks, 1 month, 3 months, and 6 months) on PD mice. EGCG also ameliorated PFF-induced degeneration of TH immuno-positive neurons and accumulation of p-α-syn in the SN and striatum at 6 months. Additionally, EGCG reduced the expression of pro-inflammatory cytokines while promoting the release of anti-inflammatory cytokines. EGCG exerts a neuroprotective effect on long-term progression of the PD model.

Green Tea Catechins Decrease Solubility of Raloxifene In Vitro and Its Systemic Exposure in Mice.

Green tea is a widely consumed beverage. A recent clinical study reported green tea decreased systemic exposure of raloxifene and its glucuronide metabolites by 34-43%. However, the underlying mechanism(s) remains unknown. This study investigated a change in raloxifene's solubility as the responsible mechanism. The effects of green tea extract, (-)-epigallocatechin gallate (EGCG), and (-)-epigallocatechin (EGC) on raloxifene's solubility were assessed in fasted state simulated intestinal fluids (FaSSIF) and fed state simulated intestinal fluids (FeSSIF). EGCG and EGC represent green tea's main bioactive constituents, flavan-3-gallate and flavan-3-ol catechins respectively, and the tested concentrations (mM) match the µg/mg of each compound in the extract. Our mouse study (n = 5/time point) evaluated the effect of green tea extract and EGCG on the systemic exposure of raloxifene. EGCG (1mM) and EGC (1.27mM) decreased raloxifene's solubility in FaSSIF by 78% and 13%, respectively. Micelle size in FaSSIF increased with increasing EGCG concentrations (> 1000% at 1mM), whereas EGC (1.27mM) did not change micelle size. We observed 3.4-fold higher raloxifene solubility in FeSSIF compared to FaSSIF, and neither green tea extract nor EGCG significantly affected raloxifene solubility or micelle size in FeSSIF. The mice study showed that green tea extract significantly decreased raloxifene Cmax by 44%, whereas EGCG had no effect. Green tea extract and EGCG did not affect the AUC0-24h of raloxifene or the metabolite-to-parent AUC ratio. This study demonstrated flavan-3-gallate catechins may decrease solubility of poorly water-soluble drugs such as raloxifene, particularly in the fasted state.

Antibacterial Assay of Green Tea (Camellia Sinensis L) Against the Growth of Enterococcus faecalis

Background: Enterococcus faecalis (E. faecalis) is often reported as an infectious agent in tooth root canals. Green tea leaves (Camellia sinesis L) contain active substances, namely catechins, which can act as an antibacterial. Research. Objective: To determine the antibacterial effectiveness of green tea extract (Camellia sinensis l) against the growth of Enterococcus faecalis bacteria. Methods: Researchers carry out tests in the laboratory, which are called laboratory experimental tests. The form of this research is Post-test Only Control Design. Researchers took samples using a purposive sampling technique with four treatments and six repetitions. The statistical test used is the Kruskal-Wallis test. Results: Based on the results of Kruskal Wallis, the p-value shows a value of 0.011 or a p-value of less than 0.05, which indicates that there is a significant difference between the Camellia sinensis L 25%, 50%, 75% treatment, and the positive control. Conclusion: Green tea extract (Camellia sinensis l) with concentrations of 25%, 50%, and 75% can inhibit E. faecalis' growth.

#19 : Green Tea Extract Inhibits Endometriosis Progression by Increasing Superoxide Dismutase Serum Levels in the Rat Models

Background and Aims: Endometriosis is a gynecological disorder defined as the presence of endometrial tissue outside the uterine cavity and affecting 10-15% of females of reproductive age. Oxidative stress has been reported as one of the main promoting factors of this disease. Green tea and its anti-angiogenic and antioxidant properties have promising potential to prevent the progression of endometriosis. This study aims to investigate the effect of green tea extract on endometriotic implant area and serum superoxide dismutase (SOD) levels in endometriosis rat models. Method: Twenty-six Balb/c female rats were randomized into two groups of equal size: experimental group (EG) and control group (CG). All subjects in EG were given green tea extract 3 mg daily for 14 days. Endometriosis was induced on the fourteenth day in all subjects in both groups. The data of the endometriotic implant area and serum SOD were obtained and analyzed fourteen days after the induction of endometriosis. Results: The endometriotic implant area of the group treated with green tea extract was significantly lower (p=0,022) RR=0,455, 95%CI=0.065-0,96) compared to the control group. The serum level of SOD in EG and CG were 5.33±0.52 ng/ml and 5.20±0.91 ng/ml, respectively (p=0.507). Conclusion: Green tea extract inhibits endometriotic implant progression and increases the level of serum SOD in endometriosis-induced rat models.

Dietary supplementation with green tea extract improves the antioxidant status and oocyte developmental competence in Italian Mediterranean buffaloes

The aim of this work was to assess the antioxidant status and the developmental competence of oocytes recovered by ovum pick-up (OPU) in Italian Mediterranean buffaloes supplemented with green tea extracts (GTE) for 90 days. Buffalo cows (n = 16) were randomly assigned to a control group receiving no supplement and a treatment group, receiving GTE starting 90 days before OPU, carried out for five consecutive sessions. Blood samples were collected before the start of supplementation with GTE (T0) and at day 45 (T1) and day 90 (T2) of supplementation, to measure ferric reducing activity (FRAP), total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT). The antioxidant status of follicles was measured as TAC on the follicular fluid collected from the dominant follicle just prior OPU, coinciding with T2, and at the end of five repeated OPU sessions (T3). Another objective was to assess in vitro the protective effects of green tea extracts on hepatic cells exposed to methanol insult. Different concentrations of GTE (0.5 μM and 1 μM) were tested on cultured hepatic cells and viability, morphology and SOD activity were assessed at 24, 48 and 72 h.Supplementation with GTE increased (P < 0.05) the number of total follicles (8.7 ± 0.5 vs 6.9 ± 0.5), the number and the percentage of Grade A + B cumulus-oocyte complexes (COCs) compared with the control (3.7 ± 0.4 vs 2.3 ± 0.3 and 57.5 ± 4.2 vs 40.4 ± 4.9 %, respectively). Oocyte developmental competence was improved in the GTE group as indicated by the higher (P < 0.05) percentages of Grade 1,2 blastocysts (44.8 vs 29.1 %). In the GTE group, plasma TAC was higher both at T1 and T2, while FRAP increased only at T2, with no differences in SOD and CAT. The TAC of follicular fluid was higher (P < 0.05) in the GTE compared to the control both at T2 and at T3 The in vitro experiment showed that co-treatment with methanol and 1 μM GTE increased (p < 0.01) cell viability at 24 h (P < 0.01), 48 h (P < 0.05) and 72 h (P < 0.01) compared with the methanol treatment co-treatment with 1 μM GTE prevented the decrease in SOD activity observed with methanol at 24 and 48 h of culture. In conclusion, the results of in vivo and in vitro experiments suggest that supplementation with GTE increases buffalo oocyte developmental competence, by improving oxidative status and liver function.

The Effect of Natural Edible Coatings on Chemical, Microbial, and Sensory Quality of Tilapia during Frozen Storage

&#x0D; &#x0D; &#x0D; Background: Preserving the quality and safety of fish and its products is a critical concern for food industry. In the present study, the effect of green tea extract and olive leaves extract-based preservative coatings on chemical, microbial, and sensory quality of wild type Nile tilapia (Oreochromis niloticus) was determined during pre-freezing ice and subsequent frozen storage.&#x0D; Methods: Forty-eight ponds raised tilapia, freshly caught in April, 2021, which were divided into three groups: group CT with no coating, group GTE with green tea extract- based coating, and group OLE with olive leaves extract-based coating. Fish samples in all groups were kept in ice for five days (1±2 °C) and then subjected to freezing (-18±2 °C) for 105 days. Chemical (moisture, ash, protein, fat, Total Volatile Basic-Nitrogen (TVB- N), pH) and microbial (Aerobic Plate Count (APC), Total Coliform (TC), Faecal Coliform (FC), Escherichia coli) parameters as well as sensory attributes (appearance, odour, acceptability, flesh color, Total Quality Index (TQI)) of tilapia in all groups were analysed after five days of ice storage and 15, 45, 75, and 105 days of frozen storage.&#x0D; Results: APC of tilapia treated with preservative coatings remained below the permissible limit (&lt;5×105 Colony Forming Unit (CFU)/g) throughout the storage period. After five days, content of TVB-N in untreated samples of tilapia was 32.94±2.30 mg/100 g compared to 5.05±2.19 and 7.24±2.89 mg/100 g in tilapia treated with green tea and olive leaves extract-based coating, respectively. Fat content of untreated tilapia was significantly (p&lt;0.05) reduced to 0.05±0.01% at the end of the study period from the the initial content of 0.24±0.04%. However, the tilapia treated with preservative coatings achieved significantly (p&lt;0.05) lower scores of TQI compared with the untreated one owing to the coloration of fish with extract solution.&#x0D; Conclusion: Green tea extract and olive leaves extract-based coatings can, therefore, be used to improve fish quality and safety during storage. However, there is a need to change consumer’s perception about the sensory attributes of fish.&#x0D; &#x0D; &#x0D;

Green tea extract and hydroxyl-chloroquine combination enhances apoptosis in A549 non-small cell lung cancer cells.

Polyphenols, including catechins from green tea extract, have long been known for their potential anti-tumour activities. However, the precise mechanisms underlying their actions remain unclear. This study aimed to investigate the effects of green tea extract on A549 cells, a type of non-small lung cancer cells. A549 cells treated with green tea extract (GTE) were examined using an inverted light microscope and a fluorescence microscope. Cell sensitivity was evaluated using the MTT assay, while cell death was assessed using the Tali image-based cytometer. Ultra structural changes were observed using a transmission electron microscope. The findings suggested that even at the highest dose tested (150 µM), GTE did not exhibit toxic effects on A549 cells. Likewise, treatment with GTE resulted in a minimal, dose-dependent increase in the population of apoptotic cells. However, the analysis of cell structures using light and electron microscopy revealed an enhanced accumulation of vacuole-like structures in response to GTE. Moreover, under the fluorescence microscope, an increase in acidic vesicular organelles and the formation of LC3-II puncta were observed following GTE treatment. Assessment of autophagy function indicated that GTE-induced autophagy may serve as a self-protective mechanism against cytotoxicity, as blocking autophagy with bafilomycin A1 reduced cell viability and enhanced necrotic cell death in response to GTE treatment. In summary, our results demonstrate that A549 cells are insensitive to both low and high concentrations of green tea extract, likely due to the induction of cytoprotective autophagy. These findings suggest that the potential utility of GTE in lung cancer therapy may lie in its synergistic combinations with drugs or small molecules that target autophagy, rather than as a standalone therapy.

Effect of Green Tea Extract on Spermatozoa Quality of Peranakan Ongole Bull On Frozen Storage

Low-temperature storage can often result in spermatozoa damage. It occurs due to Reactive Oxygen Species, leading to changes in the lipid composition of the membrane. Antioxidant compounds are needed to prevent ROS. Green tea extract (Camelia sinensis) can be used as an antioxidant agent. This study aimed to determine the effect of green tea extract in tris egg yolk on spermatozoa quality of Ongole Peranakan (PO) cattle. This study used a completely randomized design (CRD) with five extract treatments (0%, 1%, 2%, 3%,4%) and four repetitions. The parameters used were motility, viability, and membrane integrity. The data were analyzed with ANOVA and Duncan's test. Based on the results of the ANOVA test, the addition of green tea extract has a significant effect on spermatozoa quality of PO cattle in frozen storage (P0.005). The best results were obtained by the addition of 3% extract that was able to maintain the quality of post-freezing spermatozoa with average motility, viability, and membrane integrity of 47.44±0.166, 55.14±0.449, and 53.72±0.599. The addition of 3% green tea extract into tris egg yolk can maintain motility, viability, and membrane integrity in spermatozoa of PO cattle inside frozen storage, by adding green tea extract to diluent, spermatozoa can be stored for a long time at low temperatures making it easier for people to carry out artificial insemination.

Potential effect of green tea extract for adjuvant treatment of acute ischemic stroke by s100ß upregulation in non-thrombolysis patient

Potential effect of green tea extract for adjuvant treatment of acute ischemic stroke by s100ß upregulation in non-thrombolysis patient

Evaluation of structural and functional properties of citrus pectin film enriched with green tea extract

AbstractThe effects of green tea extract (GTE) concentrations (0%, 1%, 2%, 3%, 4%, and 5%) on the thicknesses, mechanical strengths, storage/loss moduli, glass transition temperatures (Tg), chemical structures, morphologies, antioxidant activities, moisture contents, and gas permeabilities of low methoxyl pectin films were investigated in this study. A decrease in the percent elongation and moisture contents accompanied by an increase in the tensile strengths, Tg and elastic and storage moduli were observed with increasing, but low concentrations of GTE in the pectin films. This rate of change slowed at higher GTE concentrations. The thicknesses of the pectin films were not significantly affected by the concentrations of GTE. The FTIR results showed increasing ester and hydrogen bonding formations with increasing concentrations of GTE from 0% to 2% in the pectin. When the GTE concentration increased from 2% to 5%, there was an increase in ester, but a decrease in the H‐bonding. The x‐ray diffraction results showed that the crystallinity of the films increased as a result of increasing GTE contents. The results of the antioxidant activities and oxygen and water vapor barrier properties showed an enhancement due to the higher concentrations of GTE. Therefore, GTE can be incorporated into low methoxyl pectin in order to make films with desired mechanical strength, gas barrier, and antioxidant properties.

Effect of green tea extract on heat-induced protein interactions and rennet coagulation in milk

The impact of green tea extract (GTE) on heat-induced milk protein interactions and enzymatic coagulation of milk was investigated. GTE addition affected the renneting process, more apparent for heat-treated samples. The enzymatic phase of rennet coagulation was negatively affected by GTE, with a significantly lower amount of κ-casein hydrolysis for intense heat-treated samples. Gel characteristics of raw milk were unaffected by GTE, but mild heat-treated samples with GTE displayed decreased gel firmness and increased water holding capacity compared with control samples. Model studies conducted with purified β-lactoglobulin A and κ-casein revealed that GTE caused a significant impact on interactions between denatured β-lactoglobulin A and κ-casein. Heat-induced large aggregate/complex formation between β-lactoglobulin A and κ-casein in milk samples was not significantly affected, highlighting the importance of the reaction medium. The presence of casein micelles in milk, which are strong candidates for phenolic binding, may ultimately impact protein–protein interactions.