scholarly journals A predictive approach to the antioxidant capacity assessment of green and black tea infusions

Author(s):  
Małgorzata Muzolf-Panek ◽  
Anna Kaczmarek ◽  
Anna Gliszczyńska-Świgło

AbstractContemporary consumers drink significant amounts of tea because of its health–benefits mainly associated to the presence of polyphenols with high antioxidant activity. Therefore, the information how to obtain tea infusion of the highest quality, i.e. with high antioxidant capacity is needed. In this study, the various models for the prediction of total polyphenols and antioxidant activity of green and black tea infusions were developed and compared. Three mathematical equations: Spiro’s, Peleg’s and logarithmic, and two data mining techniques: multivariate adaptive regression splines (MARS) and artificial neural networks (ANNs) were used to build the predictive models. The results obtained show that Spiro’s model could be used for the prediction of green tea quality expressed as total phenolic content or the antioxidant activity (determination coefficients above 0.99), whereas Peleg’s model is more suitable for black tea quality prediction (determination coefficients above 0.99). Data mining techniques (MARS and ANNs) enable to create models fast and of simple application with very good acceptability (determination coefficients above 0.99).

Author(s):  
Sonia Ancuta Socaci ◽  
Anca Farcas ◽  
Camelia Tomele ◽  
Liana Salanta ◽  
Luminita Varva ◽  
...  

The leaves from Camellia sinensis are used from ancient times for preparation of tea but also as raw material for different extracts which are used in food industry as well as in pharmaceutical or cosmetic products. Due to the increasing interest in tea health benefits, the aim of the present study was to characterize several brands of green and black tea found on local market, regarding their content in total phenolic compounds, flavonoids and antioxidant capacity. Total phenolics and flavonoids were determined spectrophotometrically using a modified Folin-Ciocalteu method, respectively a chromogenic system of NaNO2–Al(NO3)3–NaOH based method. The antioxidant capacity of each tea sample was assessed through the evaluation of free radical scavenging effect on 2,2-diphenyl-1-picrylhydrazyl. The results obtained for the green and black tea samples varied widely, depending on the tea variety. The antioxidant capacity of the analyzed teas ranged between 12.10 and 40.03%RSA, while the total phenolic content was within 2090 and 6080 mg GA/ 100g. The concentrantion in flavonoids was between 9.04 and 15.34 g/100g of tea.


Author(s):  
Naficeh Sadeghi ◽  
Masoomeh Behzad ◽  
Behrooz Jannat ◽  
Mannan Hajimahmoodi ◽  
Mohammad Reza Oveisi ◽  
...  

Tea is the most widely consumed and popular non-alcoholic beverage in the world. Reactive oxygen spices may cause wide range of damages to biological systems. Purpose of this study was to determine the total antioxidant capacity and total phenolic of different black tea samples in Iran. The FRAP (Ferric reducing antioxidant power) assay was used for antioxidant activity. The total phenolic content was measured based on the Folin-Ciocalteu method. The results showed that all samples had substantial antioxidant activity and total phenolic content. Iranian tea samples had significantly the lowest 0.98 ± 0.15, 0.75 ± 0.17 µmoll-1 and Kenya tea samples had significantly the highest 2.67 ± 0.61, 2.10 ± 0.65 µmoll-1 amount of total antioxidant capacity and total phenolic, respectively. A linear positive relationship was observed between the antioxidant activity and total phenolic content of the black tea samples. These findings suggest that black tea can be considered as natural source of antioxidant and total phenolic compounds.


2017 ◽  
Vol 100 (6) ◽  
pp. 1694-1699 ◽  
Author(s):  
Wojciech Koch ◽  
Wirginia Kukula-Koch ◽  
Kazimierz Głowniak

Abstract Black tea infusions are one of the most popular beverages across the world. Their extract composition depends on several factors, brewing time being one of the most important determinants. The aim of the present study was to determine the catechin composition of different black tea infusions using a validated LC electrospray ionization time-of-flight MS method. Additionally, total phenolic content (TPC) and antioxidant activity of infusions were evaluated using Folin–Ciocalteu reagent and stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). An optimized LC-MS method enabled the precise identification of the studied catechins [epicatechin (EC), EC gallate (ECG), epigallocatechin (EGC), and epigallocatechin-3-gallate (EGCG)] and gallic acid (GA). The major catechin in all investigated teas was EGC (25.6 mg/100 cm3 after 4 min of brewing). EC was present at the lowest concentration in all extracts. TPC and antiradical scavenging activity were in a good agreement with catechins and GA content. In general, the longer the brewing time, the higher the concentration of catechin, TPC, and antioxidant activity values. However, it should be noted that after 2 min brewing, most phenolics had already been extracted, and extract composition did not significantly change at a prolonged extraction time.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1311
Author(s):  
Simona Dobrinas ◽  
Alina Soceanu ◽  
Viorica Popescu ◽  
Ionela Carazeanu Popovici ◽  
Daniela Jitariu

The purpose of this study was to investigate the antioxidant capacity of different tea plant: mint, linden, chamomile, St. John’s wort, green and black tea in relation to total phenolic content. The antioxidant capacity of the tea infusions at different brewing times was determined using DPPH assay while the total phenolic content (TPC) was assessed using the modified Folin-Ciocalteu method. The results showed that there were significant statistical differences in antioxidant capacity depending on infusion time, according to one-way ANOVA analysis. Leaves used as components of tea infusions were analyzed by FAAS for their content of iron and copper in the dry product and in the infusion. The correlation between TPC and DPPH capacity of tea plant infusions was evaluated by Pearson correlation matrix. Total phenolics compounds content was positively and significantly correlated with DPPH capacity for all infusions time. Significant correlation was observed between TPC and the copper concentration (p < 0.05). Consequently, the correlations between the physicochemical parameters, TPC, DPPH capacity, Fe and Cu content suggested that the TPC may be a good indicator of the DPPH capacity in the tea infusions and also, suggested the influence of antioxidant compounds on mineral bioavailability.


2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Sofia C. Lourenço ◽  
Débora A. Campos ◽  
Ricardo Gómez-García ◽  
Manuela Pintado ◽  
M. Conceição Oliveira ◽  
...  

Pineapple peel still contains an important amount of phenolic compounds and vitamins with valuable antioxidant activity. In this way, the aim of this study was the recovery of the bioactive compounds from pineapple peel using environmentally friendly and low-cost techniques, envisaging their application in food products. From the solid-liquid extraction conditions tested, the one delivering an extract with higher total phenolic content and antioxidant capacity was a single extraction step with a solvent-pineapple peel ratio of 1:1 (w/w) for 25 min at ambient temperature, using ethanol-water (80–20%) as a solvent. The resulting extract revealed a total phenolic content value of 11.10 ± 0.01 mg gallic acid equivalent (GAE)/g dry extract, antioxidant activity of 91.79 ± 1.98 µmol Trolox/g dry extract by the DPPH method, and 174.50 ± 9.98 µmol Trolox/g dry extract by the FRAP method. The antioxidant rich extract was subjected to stabilization by the spray drying process at 150 °C of inlet air temperature using maltodextrin (5% w/w) as an encapsulating agent. The results showed that the antioxidant capacity of the encapsulated compounds was maintained after encapsulation. The loaded microparticles obtained, which consist of a bioactive powder, present a great potential to be incorporated in food products or to produce bioactive packaging systems.


Genetika ◽  
2020 ◽  
Vol 52 (3) ◽  
pp. 825-834
Author(s):  
Emre Sevindik ◽  
Sinem Aydin ◽  
Mehmet Paksoy ◽  
Bahar Sokmen

The genus Inula belongs to family Asteraceae and it is medicinally important because it possesses cytotoxic, anticancer, hepatoprotective, antibacterial and anti-inflammatory properties. The aim of this research was to explore antioxidant and anti-urease activities of fifteen Inula taxa in Turkey. Ethanol extracts of Inula taxa were obtained by Soxhlet extraction. Antioxidant activity was determined through total antioxidant activity, total phenolic content and copper reducing antioxidant capacity (CUPRAC) analyses. The highest total phenolic content and total antioxidant capacity were found in I. orientalis (158.54?0.002 ?g GAE/mL) and I. macrocephala (189.16?0.002 ?g AAE/mL). CUPRAC activity increases with the increasing concentration of the extracts and the standard. Moreover, all the tested plants exhibited better anti-urease activity than standard thiourea except for I. anatolica and I. thapsoides subsp. thapsoides. Results obtained from this study demonstrate that Inula species might be utilized as a probable natural source in the pharmaceutical and food industries but further and more specific studies are needed to determine active antioxidative and anti-urease compounds in the extracts.


2018 ◽  
Vol 2 (2) ◽  
pp. 39
Author(s):  
Rosyanne Kushargina ◽  
Rimbawan Rimbawan ◽  
Budi Setiawan

<p><em>Smoking </em><em>can </em><em>enhance </em><em>free radicals on blood plasma. Many previous studies proved that tea is a source of antioxidants which might reduce free radicals. Green tea is known to have the higher antioxidant capacity compared to </em><em>black tea</em><em>.</em><em> This study aim</em><em>s </em><em>to analyze the effect </em><em>of green tea on reduction of free radicals on moderate smokers</em><em>, using a pre-post experimental design. </em><em>Green tea infusions were prepared with commercially available dried tea leaves (Green Tea Gamboeng Series) from the </em><em>Research</em><em> </em><em>Centers of Tea</em><em> </em><em>and</em><em> </em><em>Cinchona</em><em> Gambung, West Java. </em><em>Nine moderate smokers (11-21 cig/day) aged 30-45 years were instructed to drink 200 ml green tea three times a day for </em><em>four</em><em> weeks. Total Antioxidant Capacity (TAC) of blood serum was measured at baseline and after four weeks intervention period. The level of TAC significantly increased from 1.18 m mol/L to 1.34 m mol/L after </em><em>four</em><em> weeks intervention (P=0.000). These results prove that drinking 200 ml of green tea </em><em>three</em><em> times a day for </em><em>four</em><em> weeks has a significant benefit reduc</em><em>ing f</em><em>ree radicals of moderate smokers. Moderate smokers are advised to consume green tea continuously to sustain these positive effects.</em><em></em></p>


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Lisa Garretson ◽  
Catrin Tyl ◽  
Alessandra Marti

While extensive research has been performed on the composition and cooking quality of commodity beans, relatively little is known about pigmented heirloom varieties and the effects of processing on their antioxidant capacity. The aim of this study was to evaluate the effect of soaking and cooking on antioxidants in four heirloom bean varieties compared to Pinto. Water absorption kinetics, soaking and cooking time, DPPH radical scavenging activity, and total phenolic and total flavonoid content were determined in raw, soaked, and cooked samples. Heirlooms required less time to hydrate compared to Pinto, whereas cooking times were similar. The effect of soaking on antioxidant capacity and flavonoids was minimal compared to cooking, which led to losses of up to 57%. Each pigmented heirloom bean had specific characteristics, and three of them had equal or higher amounts of antioxidants or antioxidant activity than Pinto at every processing step. Among heirlooms, Koronis Purple and Jacob’s Cattle had the highest antioxidant activity and Jacob’s Cattle and Tiger’s Eye the highest amount of flavonoids, even after cooking.


Antioxidants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 117 ◽  
Author(s):  
Federica Blando ◽  
Rossella Russo ◽  
Carmine Negro ◽  
Luigi De Bellis ◽  
Stefania Frassinetti

Plant extracts are a rich source of natural compounds with antimicrobial properties, which are able to prevent, at some extent, the growth of foodborne pathogens. The aim of this study was to investigate the potential of polyphenolic extracts from cladodes of Opuntia ficus-indica (L.) Mill. to inhibit the growth of some enterobacteria and the biofilm formation by Staphylococcus aureus. Opuntia ficus-indica cladodes at two stages of development were analysed for total phenolic content and antioxidant activity by Oxygen Radical Absorbance Capacity (ORAC) and Trolox equivalent antioxidant capacity (TEAC) (in vitro assays) and by cellular antioxidant activity in red blood cells (CAA-RBC) (ex vivo assay). The Liquid Chromatography Time-of-Flight Mass Spectrometry (LC/MS–TOF) analysis of the polyphenolic extracts revealed high levels of piscidic acid, eucomic acid, isorhamnetin derivatives and rutin, particularly in the immature cladode extracts. Opuntia cladodes extracts showed a remarkable antioxidant activity (in vitro and ex vivo), a selective inhibition of the growth of Gram-positive bacteria, and an inhibition of Staphylococcus aureus biofilm formation. Our results suggest and confirm that Opuntia ficus-indica cladode extracts could be employed as functional food, due to the high polyphenolic content and antioxidant capacity, and used as natural additive for food process control and food safety.


Sign in / Sign up

Export Citation Format

Share Document