scholarly journals Effect of Gelatin-Based Edible Coatings Incorporated with Aloe vera and Black and Green Tea Extracts on the Shelf Life of Fresh-Cut Oranges

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Radi ◽  
Elham Firouzi ◽  
Hamidreza Akhavan ◽  
Sedigheh Amiri

The aim of this study was to evaluate the effect of gelatin coating incorporated with Aloe vera gel (50,100%) and green and black tea extracts (5,10%) on physicochemical, microbial, and sensorial properties of fresh-cut oranges at 4°C for 17 days. Significant differences in terms of quality parameters were observed between the control and coated fresh-cut oranges. The highest variation of quality parameters was observed in control, while the least variations were observed in coated slices with 100% Aloe vera and 10% green tea extract. The weight loss was increased with time, but the coating treatment especially with 100% Aloe vera had significant effect on the prevention of weight loss. Also, Aloe vera coated samples obtained the highest score in sensory evaluation. Coating with gelatin incorporated with Aloe vera and green tea extracts successfully retarded the microbial growth and therefore extended the shelf life of fresh-cut oranges during cold storage.

2010 ◽  
Vol 30 (8) ◽  
pp. 884-896 ◽  
Author(s):  
Amar K Chandra ◽  
Neela De ◽  
Shyamosree Roy Choudhury

Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5′-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.


Author(s):  
Andi Arjuna ◽  
Winda Setya Pratama ◽  
Sartini Sartini ◽  
Mufidah Mufidah

Tea (Camellia sinensis L.) has an activity as an antibacterial, widely studied to plankton cells, without further researching into biofilm cell. Therefore, this research had been conducted to initially evaluate the activity of green- and black-tea extracts in inhibiting Streptococcus mutans biofilm. Green and black tea leaves were extracted using 70% methanol. Determination of MIC was subsequently performed by microdilution method. Next, the biofilm formation and inhibition were run through microtiter plate method using flexible U-bottom PVC 96 wells, which then observed using microplate reader on λ = 515 nm. As The results, MIC for green and black tea extract stood at 4 mg/mL, 6 mg/mL respectively. The biofilm inhibitory activity of black tea extract was at 8 and 10 mg/mL inhibiting 6 % and 12.5 % S. mutans. Green tea extract showed that concentration of 4 to 10 mg/mL was able to inhibit biofilm growth by 24%; 45%; 48% and 53%. Thus, through microtiter plate assay, it could be concluded that tea extract has potent antibiofilm to S. mutans, where green tea extract has better activity than black tea extract.


2009 ◽  
Vol 56 (12) ◽  
pp. 660-664 ◽  
Author(s):  
Takahisa Miyamoto ◽  
Motokazu Nakayama ◽  
Naofumi Shigemune ◽  
Hajime Tokuda ◽  
Tomoyo Matsushita ◽  
...  

1994 ◽  
Vol 57 (1) ◽  
pp. 54-58 ◽  
Author(s):  
GOW-CHIN YEN ◽  
HUI-YIN CHEN

The antimutagenic effects of various tea extracts prepared from nonfermented tea (green tea), semifermented tea (oolong tea and pouchong tea), and fermented tea (black tea) were investigated by Salmonella/microsome assay. No mutagenicity or toxicity in Salmonella typhimurium TA98 and TA100 was observed with any tea extract. The tea extracts markedly inhibited the mutagenicity of 2-amino-3-methylimidazo(4,5-f)quinoline, 3-amino-1,4-dimethyl-5H-pyridol(4,3-b)indole,2-amino-6-methyldipyrido(l,2-a:3′,2′-d)imidazole, benzo[a]pyrene, and aflatoxin B1 toward S. typhimurium TA98 and TA100 in the presence of S9 mixture, especially those of oolong and pouchong teas inhibited over 90% mutagenicity of these five mutagens at the dosage of 1 mg per plate. Among four tea extracts, black tea exhibited the weakest inhibitory effect on mutagenicity of these five mutagens. The mutagenicity of 4-nitroquinoline-N-oxide, a direct mutagen, was not inhibited by black and oolong tea extracts to S. typhimurium TA98 in the absence of S9 mixture but was increased by the tea extracts at the dose of 1 mg per plate to S. typhimurium TA100. As the antimutagenic effect of semifermented tea was stronger than nonfermented and fermented teas, some antimutagenic substances might be formed during manufacturing processes of tea.


Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1862 ◽  
Author(s):  
Nenad Naumovski ◽  
Alexandra Foscolou ◽  
Nathan M. D’Cunha ◽  
Stefanos Tyrovolas ◽  
Christina Chrysohoou ◽  
...  

Tea is one of the most-widely consumed beverages in the world with a number of different beneficial health effects, mainly ascribed to the polyphenolic content of the tea catechins. The aim of this study was to examine the consumption of green, black, or no tea, in relation to the previously validated successful ageing index (SAI; higher values “healthier” ageing) in a combined analysis of adults aged >50 years old from the ATTICA (n = 1128 adults from Athens, Greece metropolitan area) and the MEDiterranean Islands Study (MEDIS) (n = 2221 adults from various Greek island and Mani) studies. After adjusting for age, sex, smoking, and coffee consumption, green tea was positively associated with SAI (b ± SE: 0.225 ± 0.055, p < 0.001), while black tea was negatively associated with SAI (unstandardized b coefficient ± Standard error: −0.807 ± 0.054, p < 0.001). Green tea (vs black tea) consumption, had higher odds of a SAI of over 3.58 out of 10 (OR: 1.77, 95% CI: 1.38–2.28). Green tea consumption was also associated with higher levels of physical activity (p < 0.001) and reduced likelihood of hypertension (p = 0.006) compared with black tea. Two possible mechanisms are that green tea possesses high levels of catechins such as (−)-epigallocatechin 3-gallate and l-theanine compared with black tea. Therefore, the present analysis supports both the role of green tea constituents in successful ageing, as well as its role as an important component of an overall healthy diet in adults aged 50 years and over from these two epidemiological studies.


2016 ◽  
Vol 33 ◽  
pp. 534-541 ◽  
Author(s):  
Daniel Carrizo ◽  
Gonzalo Taborda ◽  
Cristina Nerín ◽  
Osvaldo Bosetti

LWT ◽  
2014 ◽  
Vol 55 (2) ◽  
pp. 559-564 ◽  
Author(s):  
A.M. López de Lacey ◽  
M.E. López-Caballero ◽  
P. Montero

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Vahid Maleki ◽  
Ehsaneh Taheri ◽  
Parisa Varshosaz ◽  
Fatemeh Pourteymour Fard Tabrizi ◽  
Jalal Moludi ◽  
...  

Abstract Background Polycystic ovary syndrome (PCOS), as the most common endocrine disorder in reproductive-aged women, is characterized by oxidative stress and ovarian tissue inflammation. Green tea extract (GTE) potentially possesses therapeutic effects for PCOS because of the antioxidant and anti-inflammatory compounds. This systematic review evaluates the potential roles of GTE on metabolic variables, hormone levels, and ovarian function in PCOS. Methods A systematic review was conducted of published studies reporting the effects of GTE on PCOS. Several major databases, including PubMed, SCOPUS, and Google Scholar, were searched up from inception to April 2021. Clinical trials and animal studies that assessed the effects of GTE on PCOS were eligible for inclusion. Results Of 314 articles found in the search, four human studies and four animal studies were included. All studies in humans showed the effects of GTE on weight loss. GTE’s effect on decreasing testosterone levels in humans and LH levels in animals were also reported. In addition, increases in FSH and progesterone levels in animal models were observed. Although GTE improved fasting blood sugar and insulin levels, the effect of GTE on inflammatory parameters, such as TNF-alpha and IL-6 and antioxidant status, was limited to animal studies. Conclusion Therefore, this review suggests that GTE could be considered a potential agent to attenuate PCOS complications mainly due to its effect on weight loss and glycemic levels. However, more studies are needed to formulate conclusions about the effects and mechanisms of GTE in PCOS.


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