cognitive-function

Matcha consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on cognitive performance.

Recent Research Papers on
cognitive-function

Phytochemical stability in dried apple and green tea functional products as related to moisture properties

Author: Mark E. Corey and William L. Kerr and Jake H. Mulligan and Vera Lavelli

In this study, apple products made with and without added green tea extract were freeze-dried and stored for up to 45 days at 30 °C in low and intermediate moisture environments (water activity, aw, 0.11, 0.22, 0.32, 0.57, and 0.75). Kinetic models were developed for the changes in color and decreases in contents of selected green tea and apple monomeric and polymeric flavanols and ascorbic acid. Moisture isotherms were developed for each product. At various moisture levels, the glass transition temperature (Tg) was measured by \{DSC\} and water mobility by 1H NMR. Chemical changes were related to Tg, aw, and water mobility in the products. Phytochemical degradation occurred more rapidly at higher moisture contents, except for caffeine which was stable. In the product containing apple with green tea, the content of monomeric flavan-3-ols decreased by 34% and 39% after 45 days of storage at aw of 0.56 and 0.75, respectively. Phytochemical degradation correlated with increasing aw, Tg, and water mobility. This study showed that, in general, storage at aw 0.75 most affected phytochemical stability and color.

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Green tea and grape seed extracts — Potential applications in food safety and quality

Author: A.V.S. Perumalla and Navam. S. Hettiarachchy

Using “natural green” plant extracts or their derived products in various food and beverage applications is an increasing trend in the food industry. Selection of these plant extracts and their application depends on their functional properties, availability, cost effectiveness, consumer awareness and their effect on the sensory attributes of the final product. Green tea extract (GTE) and grape seed extract (GSE) are two popular plant extracts that have been widely used in various food and beverage applications. Green tea is a widely consumed beverage that has attracted more attention in the recent years due to its health benefits like antioxidant, antimicrobial, anticarcinogenic and anti-inflammatory properties. Grape seed extract is derived from the grape seeds that is extracted, dried and purified to produce polyphenolic compounds-rich extract that also has well documented antioxidant, antimicrobial and anti-inflammatory properties. These two plant extracts (polyphenolic and proanthocyanidin rich compounds) have potential antioxidant properties by inhibiting the lipid oxidation and warmed over flavors and antimicrobial activities against major food borne pathogens like Listeria monocytogenes, Salmonella Typhimurium, Escherichia coli O157:H7, and Campylobacter jejuni in preventing pathogen contamination. Furthermore, they have demonstrated synergism in antimicrobial activity when used in combination with organic acids (malic, tartaric acid, benzoic acids etc.), bacteriocins like nisin or chelating agents like EDTA in various model systems including fresh produce (fruits and vegetables), raw and ready-to-eat meat and poultry products. Apart from beneficial effects of grape seed extract in food safety and quality, concerns regarding the side effects of GSE are also addressed. Nevertheless, persistent recalls of the food products involving foodborne pathogens despite various control measures calls for efficient bacteriostatic and bactericidal agents and technologies to deliver the active components for an effective inhibition of pathogens. Therefore, further research involving electrostatic spray and nanoscale delivery of the active components present in these natural, green, plant extracts and using them as a component in multiple hurdle approach would enhance the food safety and quality in addition to providing alternative “green” solutions to the food processors.

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847 EFFECT OF COFFEE AND GREEN TEA CONSUMPTION ON LIVER ENZYME AND METABOLIC SYNDROME IN KOREAN POPULATION

Author: D.W. Jun and E.K. Kim and H.S. Choi and Y.I. Kown and W. Sohn and O.W. Kwon and K.N. Lee and H.L. Lee and O.Y. Lee and B.C. Yoon and T.Y. Kim and J.H. Sohn

Background: There are several epidemiologic studies that coffee and tea consumption could lower serum liver enzyme activity, and inhibit the progression of liver disease in high-risk subjects. However, many conflicting results have been also reported according to type of coffee and whether the use of filters. Most studies were base on specific cohort group and there are few general population base studies. This study examined on population based study whether coffee has a protective effect when consumed in moderate quantities in metabolic syndrome and liver inflammation. Methods: We used cross-sectional data on coffee, tea consumption frequency, and metabolic parameters of 5,283 adults, aged 20 years and older, who participated in the third Korea National Health and Nutrition Examination Survey (KNHANES). We examined the relationship between coffee, tea, and caffeine intake and metabolic parameters using linear regression. Additionally, we examined the relationship with liver enzyme activity using logistic regression. Intake was assessed by a food frequency questionnaire. Result: In our study, more than 90% subjects intake instant coffee mix (mix with confectioners’ sugar, powdered creamer, and soluble coffee). Total calorie intake and body mass index were higher in individuals with coffee intake >2 cups daily compared with those with no coffee use (p < 0.001 vs. p = 0.021, respectively). However, a gradual increase in the frequency of coffee consumption was associated with stepwise decrease in prevalence of hypertension, dyslipidemia, and abnormal fating glucose, which was independent of total calorie, and BMI. The prevalence of metabolic syndrome was strikingly decreased from 48.8%, 46.5%, to 40.9% according to the quartile of coffee consumption (p = 0.01, p for trend <0.001). After adjusting for other covariates, the differences remained significant. But frequency of coffee consumption did not affect the liver enzyme activity on general population and high risk group. In cases of normal BMI subjects (23–25 kg/m2), coffee intake had a tendency to increased liver enzyme activity. Frequency of green tea intake did not showed protective effects on liver and metabolic aspects. Conclusion: In this large, national, population-based study, consumption of coffee was associated with lower the risk of metabolic syndrome.

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1H NMR-based metabolomic characterization during green tea (Camellia sinensis) fermentation

Author: Jang-Eun Lee and Bum-Jin Lee and Jin-Oh Chung and Hyun-Jung Shin and Sang-Jun Lee and Cherl-Ho Lee and Young-Shick Hong

The metabolic behavior of green tea (Camellia sinensis) during tea fermentation was characterized by 1H NMR spectroscopy coupled with multivariate statistical analysis to provide comprehensive information on changes in metabolites induced by tea fermentation. Fourteen tea metabolites of epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), epigallocatechin-3-gallate (EGCG), theanine, alanine, acetate, quinate, glutamate, caffeine, sucrose, glucose, and gallate, as identified by 1H NMR spectroscopy, were responsible for metabolic differentiation between green tea and fermented tea by principal component analysis. During tea fermentation, levels of EC, EGC, ECG, EGCG, quinate, caffeine, and sucrose were decreased, whereas gallate and glucose levels were increased. In particular, unique changes in caffeine and gallate levels were observed during tea fermentation, which caffeine and gallate levels have been shown to vary after tea fermentation among many reports to date. This study highlights that metabolomics with global profiling and a highly reliable and reproducible 1H NMR spectroscopic data set can provide a better understanding of unique changes in tea metabolites during tea fermentation.

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Antiobesity effects of green tea catechins: a mechanistic review

Author: Tia M. Rains and Sanjiv Agarwal and Kevin C. Maki

Green tea catechins (GTC) are polyphenolic compounds present in the unfermented dried leaves of the plant, Camellia sinensis. Results from a number of randomized, controlled intervention trials have shown that consumption of GTC (270 mg to 1200 mg/day) may reduce body weight and fat. There are several proposed mechanisms whereby GTC may influence body weight and composition. The predominating hypothesis is that GTC influences sympathetic nervous system (SNS) activity, increasing energy expenditure and promoting the oxidation of fat. Caffeine, naturally present in green tea, also influences SNS activity, and may act synergistically with GTC to increase energy expenditure and fat oxidation. Other potential mechanisms include modifications in appetite, up-regulation of enzymes involved in hepatic fat oxidation, and decreased nutrient absorption. This article reviews the evidence for each of these purported mechanisms, with particular reference to studies in humans.

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Beverages containing soluble fiber, caffeine, and green tea catechins suppress hunger and lead to less energy consumption at the next meal

Author: Brett E. Carter and Adam Drewnowski

Previous research has shown that beverages containing soluble fibers can decrease energy intake at the next meal among normal weight participants. Caffeine and green tea catechins have separately been associated with increased satiety. The present study examined the satiating power of a beverage containing soluble fiber as well as a beverage containing the same fiber, caffeine and green tea catechins. These two test beverages were evaluated in comparison to an equal calorie control beverage as well as a no-beverage control condition. All beverage preloads were presented three times for a total of 0.28–0.35 MJ and 0–30 g fiber. Dependent measures were appetite ratings and calorie intake at a test meal. The no-beverage condition was associated with the highest ratings for hunger and the lowest ratings for fullness when compared to the other three beverage conditions. Of the three beverage conditions, the beverage containing the fiber, green tea catechins, and caffeine created the lowest hunger and the highest fullness ratings. That condition was also associated with the lowest energy intake at the next meal. The present findings indicate that the beverage containing caffeine and green tea catechins in combination with soluble fiber decrease appetite and energy intake relative to a beverage with equal caloric content.

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Acute neurocognitive effects of epigallocatechin gallate (EGCG)

Author: Andrew Scholey and Luke A. Downey and Joseph Ciorciari and Andrew Pipingas and Karen Nolidin and Melissa Finn and Melissa Wines and Sarah Catchlove and Alirra Terrens and Emma Barlow and Leanne Gordon and Con Stough

Green tea is reported to have wide ranging beneficial health outcomes across epidemiological studies, which have been attributed to its flavonoid content. We investigated whether the flavonoid epigallocatechin gallate (EGCG) modulates brain activity and self-reported mood in a double-blind, placebo controlled crossover study. Participants completed baseline assessments of cognitive and cardiovascular functioning, mood and a resting state electroencephalogram (EEG) before and then 120 min following administration of 300 mg EGCG or matched placebo. EGCG administration was associated with a significant overall increase in alpha, beta and theta activity, also reflected in overall EEG activity, more dominant in midline frontal and central regions, specifically in the frontal gyrus and medial frontal gyrus. In comparison to placebo the EGCG treatment also increased self-rated calmness and reduced self rated stress. This pattern of results suggests that participants in the EGCG condition may have been in a more relaxed and attentive state after consuming EGCG. This is in keeping with the widespread consumption of green tea for its purported relaxing/refreshing properties. The modulation of brain function due to EGCG is deserving of further controlled human studies.

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Effects of catechin-enriched green tea beverage on visceral fat loss in adults with a high proportion of visceral fat: A double-blind, placebo-controlled, randomized trial

Author: Ying Zhang and Yingjie Yu and Xu Li and Shinichi Meguro and Satoshi Hayashi and Mitsuhiro Katashima and Takeshi Yasumasu and Jingzhong Wang and Keji Li

The effects of catechin-enriched green tea on Chinese adults with a high proportion of abdominal visceral fat were evaluated. Subjects (118) were randomly assigned to consume daily a beverage containing 609.3 mg catechins and 68.7 mg caffeine or a control beverage for 12 weeks. Abdominal fat area, body weight and composition were measured at week 0, week 8, and week 12. One hundred and four subjects completed the trial. Average visceral fat area, body weight, and body fat were reduced significantly by catechin-enriched green tea treatment but these effects were not seen in the control group with per-protocol sets analysis. The decrease at week 12 in the visceral fat area in the catechin group was greater than that in the control group (P = 0.04). Thus, consumption of the catechin-enriched green tea beverage for 12 weeks induced visceral fat loss in Chinese adults with a high proportion of abdominal visceral fat.

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Improved extraction of green tea components from teabags using the microwave oven

Author: Quan V. Vuong and Sing P. Tan and Costas E. Stathopoulos and Paul D. Roach

The green tea (Camellia sinensis) catechins are strong antioxidants linked with potential health benefits. Based on previous studies, it was hypothesised that the typical household conditions for brewing green tea in a teabag – 200 mL freshly boiled water for 2–3 min, as per the manufacturers’ instructions – were not sufficient to extract all the catechins and that a household microwave oven could be used to improve the extraction. The catechins and the two other main green tea components, caffeine and theanine, were monitored by HPLC. The typical household conditions only extracted 62% (61 mg/g tea), 76% (24 mg/g) and 80% (10 mg/g) of the catechins, caffeine and theanine, respectively, from the five varieties of teabags analysed. However, using microwave assisted extraction (MAE) by first brewing a teabag in 200 mL freshly boiled water for 0.5 min before irradiation for 1 min in a microwave oven (hot MAE), improved the extraction of the catechins and caffeine to 80% (80 mg/g) and 92% (29 mg/g), respectively, although the extraction of theanine was not affected. Therefore, the hot MAE technique could help maximise the extraction of the catechins for those who consume green tea for the potential health benefits of the catechins.

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3.352 EFFECTS OF GREEN TEA EXTRACT (GTE) ON HALOPERIDOL (HAL) INDUCED NEUROLEPTIC ANXIETY SYNDROME (NAS) AND PARKINSONISM IN RATS

Author: T. Malik and D.J. Haleem

Introduction: HAL elicits NAS along Parkinsonism. HAL induces c-Fos responsiveness in a distributed anxiety-related neural scheme, selected neuronal population of nucleus accumbens. Mood deficits by HAL metabolically effect via diet restriction that reduced body weight. GTE is known to control appetite and body weight while exerting anxiolytic effects. Aim: The current study testifies the hypothesis that GTE may control HAL elicited NAS with reducing Parkinsonism. Methods: Rats (n=6) were treated with one of the four treatments; oral fluid [water/GTE (1 gm/liter)] plus saline; or oral fluid plus i.p HAL (1 mg/kg/day) administration. Behavioral assessments and neurochemical analysis were performed following six weeks of treatments. Results: suggest that HAL induced decreases in fluid, food intake and growth rate were greater in GTE treated animals. GTE was shown to induce anxiogenic behavior examined in light dark box transitional test but not in fear like exploratory behavior on elevated plus maze and motor deficits on rota rod performance. HAL induced locomotor activity was suppressed, innate aversive and fear like exploratory behaviors were greater in GTE than water drinking animals. HAL induced serotonergic metabolism was increased in the caudate and nucleus accumbens and decreased in the serotonin availability in the rest of the brain regions of GTE treated animals. HAL induced decreased dopamine was increase din the nucleus accumbens of GTE drinking than water drinking animals. Conclusion: Potential mechanism involved in the greater anorexiogenic effects of GTE and greater HAL induced NAS plus Parkinsonism in GTE treated animals is proposed for demonstration in this meeting.

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