scholarly journals Effects of temperature, steeping time and particle size used in infusion brewing on total phenolic content and antioxidant activity of tea produced from young upland rice leaves

2021 ◽  
Vol 21 (02) ◽  
pp. 17477-17491
Author(s):  
Narissara Uthai ◽  

Tea was brewed from young leaves of 4 weeks old Thai upland black waxy rice plants of the cultivar ‘Damgatondam’, which has a noticeable fragrant smell from both seeds and leaves. The plants were harvested about 1 cm above soil level, washed, and cut into pieces, about 1 cm long. These pieces were then steamed for 1 min in a steamer rack, withering for 5min by spreading them out in a thin layer, pan-roasted at 70°C for 30 min, and finally dried at 70°C for 90 min. They were either kept as pieces of leaves or ground into a powder, and both were used for brewing tea by infusion in water at 4oC, room temperature (about 25oC), for 1, 3, 5, 7, 9, 11, or 15 h and brewing at 70oC or 98oC for 1, 3, 5, 7, 9, 11 or 15 min. Directly after brewing, the tea was stored at -25oC awaiting analysis. Each sample was analyzed for total phenolic content (TPC) and for antioxidant activity, by ferric reducing antioxidant power (FRAP), 2,2 diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazo line-6-sulphonic acid) (ABTS) assays. Results showed that tea brewed from ground leaves had higher antioxidant activity than tea brewed from ungrounded leaves. The highest level of extraction was at 98oC for 15 min, where the TPC was 62.79 mg GAE/100g, antioxidant activity was 278.04 for DPPH, 195.38 for ABTS and 1150.13 mg TE/100g for FRAP. Samples extracted at 4oC or room temperature also had high levels of TPC and antioxidant activity with the maximum extraction at room temperature for 15 h; where TPC was 46.76 mg GAE/100g, and antioxidant activities were 152.72 for DPPH, 140.42 for ABTS and 950.32 mg TE/100 g for FRAP. Therefore, the level of extraction for tea brewed in all four conditions depended on both temperature and brewing time. Also, extraction of high levels of bioactive compounds depended on large surface areas of the leaves being in contact with water.

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S245-S247 ◽  
Author(s):  
M. Krpan ◽  
K. Marković ◽  
G. Šarić ◽  
B. Skoko ◽  
M. Hruškar ◽  
...  

The antioxidant activities and total phenolic content of 30 samples of acacia honey from Croatian territory were analysed. Phenolics were determined by the modified Folin-Ciocalteu method, antiradical activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and potential antioxidant activity using the ferric reducing antioxidant power (FRAP) method. In all samples, physicochemical parameters (water content, electrical conductivity, total reducing sugars, sucrose content, acidity, hydroxymethylfurfural content, prolin content, optical rotation, diastase activity and invertase activity) were measured according to Croatian legislation and International regulatory standards. Honey can be considered as a dietary supplement as it contains some important components including α-tocopherol, ascorbic acid, flavonoids and phenolics. The composition and properties of honey are dependent on floral origins, climatic conditions of the produced area, processing and storage methods. The results of physicochemical analyses showed that all the values of investigated parameters are in agreement with the current legislation. Phenolic content ranged from 31.72 mg/kg to 80.11 mg/kg, antiradical activity expressed as IC50 ranged from 61.28% to 253.47% and antioxidant activity expressed as FRAP value from 6.95 to 142.43. A positive correlation was observed between total phenolic content and antioxidant activity, indicating that phenolic compounds are mainly responsible for the antioxidant power of acacia honey.


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.


2013 ◽  
Vol 31 (No. 6) ◽  
pp. 601-606 ◽  
Author(s):  
G. Šarić ◽  
K. Marković ◽  
D. Vukičević ◽  
E. Lež ◽  
M. Hruškar ◽  
...  

We determined how the antioxidant activity and total phenolic content of honey changed after being subjected to a high temperature. Antioxidant activity was determined using two methods – FRAP (ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays. Total phenolic content was determined by modified Folin-Ciocalteu method. The research was conducted on 31 samples of acacia honey and 8 samples of chestnut honey. All measurements were done at two temperatures – at 23°C (room temperature) and after 5 min of heating at 95°C. The obtained results show uneven changes of antioxidant activity and total phenolic content among individual samples, i.e. in some samples antioxidant activity decreased after heating, while in others it increased. The same applies to the total phenolic content. Statistical analysis of the results (t-test) showed no statistically significant differences between the results measured at two different temperatures (P > 0.05) in all three methods used, and in both types of honey. The only statistically significant difference (P < 0.05) was observed when using DPPH method in acacia honey.


Author(s):  
Catherine Nabbala ◽  
Wunwisa Krasaekoopt

In this study, the antioxidant activity and total phenolic content of Thunbergia laurifolia Lindl. or Rang Chuet (RC) extracts from leaf, stem and rhizome were evaluated by using ferric reducing antioxidant power assay (FRAP) and the folin ciocalteu method for total phenolic compounds (TPC).The extracts were prepared by infusion using different amount of plant powder (2.5, 5.0, and 7.5 g) at different concentrations of ethanol as 0, 25, 50, and 75% and extraction time of 24, 48, and 72 h. The crude extract of 7.5 g leaf powder extracted for 72 h using water as the extraction solvent showed the highest antioxidant properties and total phenolic content. This extraction condition produced a FRAP content of 2.62 ± 0.01 mmol Fe2+/g that was significantly differed from those of the stem and rhizome and the highest TPC content of 877.36±18.75 (mg GAE/g). The crude extract from the leaf was subsequently encapsulated by using β-cylcodextrin (BCD) and maltodextrin 20DE (MD) as coating materials using freeze drying method. The encapsulated powder was investigated for its antioxidant activity. The highest encapsulation efficiency (EE) was obtained when only maltodextrin 20DE was used. The storage stability of encapsulated T. luarifolia leaf crude extract was then studied by storing the encapsulated powder at 35, 45, and 55°C for 5 weeks. The storage temperature had no effect on the stability of the encapsulated powder when TPC was used as the criteria unlike that of FRAP which was inconsistent during storage.


2018 ◽  
Vol 17 (06) ◽  
pp. 77-84
Author(s):  
Tuyen C. Kha

The objective of this study was to investigate the efficiency of phenolic extraction and antioxidant activity from sesame cake using water extraction method and to evaluate the possibility of employing microwave irradiation to improve the extraction yield. The result showed that extraction temperature had major influence on total phenolic content and antioxidant activities of the extracts, whereas extraction time was found to be insignificant. The optimum extraction condition recommended were 90oC for 30 min in this research. Furthermore, microwave pre-treatment at 120 s could have significantly positive influence on the overall extraction yield, especially the total phenolics and antioxidants based on FRAP assay. Therefore, the obtained results suggest that sesame aqueous extracts could be a source of antioxidants with more feasible applications in food as well as other industries.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1557
Author(s):  
Niwana Wangsawat ◽  
Lutfun Nahar ◽  
Satyajit D. Sarker ◽  
Cherdchai Phosri ◽  
Andrew R. Evans ◽  
...  

Xylaria species associated with termite nests or soil have been considered rare species in nature and the few which have been reported upon have been found to act as a rich source of bioactive metabolites. This study evaluated 10 ethyl acetate extracts of five new Xylaria species associated with termite nests or soil for their antioxidant activity, and cytotoxicity against different cancer and normal cell lines. DPPH and ABTS radical scavenging activities of the extracts demonstrated strong capacity with low IC50 values. The highest observed activities belonged to X. vinacea SWUF18-2.3 having IC50 values of 0.194 ± 0.031 mg/mL for DPPH assay and 0.020 ± 0.004 mg/mL for ABTS assay. Total phenolic content ranged from 0.826 ± 0.123 to 3.629 ± 0.381 g GAE/g crude extract which correlated with antioxidant activities. The high total phenolic content could contribute to the high antioxidant activities. Cytotoxicity was recorded against A549, HepG2, HeLa and PNT2 and resulted in broad spectrum to specific activity depending on the cell lines. The highest activities were observed with X. subintraflava SWUF16-11.1 which resulted in 11.15 ± 0.32 to 13.17 ± 2.37% cell viability at a concentration of 100 µg/mL. Moreover, LC-MS fingerprints indicated over 61 peaks from all isolates. There were 18 identified and 43 unidentified compounds compared to mass databases. The identified compounds were from various groups of diterpenoids, diterpenes, cytochalasin, flavones, flavonoids, polyphenols, steroids and derivatives, triterpenoids and tropones. These results indicate that Xylaria spp. has abundant secondary metabolites that could be further explored for their therapeutic properties.


2020 ◽  
Vol 7 (1) ◽  
pp. 40-50
Author(s):  
Mohammad Khairul Alam ◽  
Rumana Tuli ◽  
Mohammad Sharif Khan ◽  
Abu Tareq Mohammad Abdullah ◽  
Maksuda Khatun ◽  
...  

Background: Polyphenolic compounds are known to provide health benefits and protect against degenerative chronic diseases. Utilization and identification of foods with a high content of these compounds are gaining greater attention nowadays. Objective: The present study reports the total phenolic content (TPC), polyphenolic composition and antioxidant activity (DPPH, FRAP and TEAC) of 10 commonly consumed leafy vegetables growing in Bangladesh. Materials and Methods: The samples were collected from different locations of Bangladesh and mixed together to ensure sample representativeness. Folin-Ciocalteu method was used for the analysis of TPC, and quantification of polyphenolic components was done by high-performance liquid chromatography (HPLC- DAD). Additionally, antioxidant activities of the selected vegetables were also analysed by utilizing DPPH, FRAP & TEAC. Results and Discussion: TPC ranged from 23.64 ± 1.20 to 45.59 ± 3.04 mg gallic acid equivalent (GAE)/g freeze-dried sample (fds). The polyphenolic spectrum ranged from 0.30 ± 0.02 to 647.42 ± 147.12 mg/100 g fds; quantity and spectrum of which varied in the vegetables. Among the studied vegetables, Centella asiatica contained the highest amount of TPC (45.59 ± 3.04 mg GAE/g fds) and also exhibited high antioxidant capacities, as documented by DPPH, FRAP and TEAC assays. Moreover, Principal component analysis (PCA) of investigated variables clearly separated Centella asiatica from other samples. Conclusion: Phenolic compounds being strong antioxidants reduce the risk of chronic diseases and the finding of this study would aware the people to take vegetables rich in phenolics. It would also fill up the data gap in the existing food composition table of Bangladesh.


2016 ◽  
Vol 46 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Marisa Cristina Aranha BATISTA ◽  
Bruno Vinicius de Barros ABREU ◽  
Richard Pereira DUTRA ◽  
Mayara Soares CUNHA ◽  
Flavia Maria Mendonça do AMARAL ◽  
...  

ABSTRACT Geopropolis, a mixture of plant resin, wax, soil and salivary secretion, is produced by the stingless bee Melipona fasciculata. This aim of this study was to investigate the chemical composition and antioxidant activity of geopropolis collected from beehives in two phytogeographical regions, flooded fields and cerrado, in the municipalities of Palmeirândia and Fernando Falcão, Maranhão State, northeastern Brazil. The geopropolis compounds were identified by gas chromatography-mass spectrometry (GC/MS). Additionally, total phenolic content was determined with the Folin−Ciocalteu reagent and antioxidant activity was evaluated in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The four geopropolis samples varied in terms of total phenolic content and antioxidant activity and the highest values were observed for geopropolis from Fernando Falcão. Triterpenes such as cycloartane, ursane and oleanane and phenolic acids (protocatechuic acid and gallic acid) were identified in the geopropolis from Palmeirândia, while the phenolic acids, gallic and ellagic acid were the main compounds in geopropolis from Fernando Falcão. The antioxidant property of geopropolis is due to its high total phenolic content and predominance of gallic acid and ellagic acid. The results showed that the plant resources in two phytogeographical regions of Maranhão used by bees for the production of geopropolis contribute to the chemical composition and bioactivity of this product.


2015 ◽  
Vol 10 (12) ◽  
pp. 1934578X1501001
Author(s):  
Tian-Peng Yin ◽  
Le Cai ◽  
Yang Chen ◽  
Ying Li ◽  
Ya-Rong Wang ◽  
...  

The total phenolic content and antioxidant activities of the acetone extract and derived fractions from the walnut ( Juglans regia) pellicle were estimated. The BuOH fraction exhibited the strongest antioxidant activity with the highest phenolic content. A phytochemical investigation of this fraction led to the isolation of three tannins, 2,3-hexahydroxydiphenoylglucose (1), pedunculagin (2) and 2,3,4,6-tetragalloylglucose (3). Pedunculagin showed high content and powerful activity, which implied that this compound plays an important role in the antioxidant activity of the walnut pellicle.


2019 ◽  
Vol 18 (6) ◽  
pp. 97-105
Author(s):  
Funda Atila

The aim of this work was to determine the total phenolic content (TPC) and the antioxidant activity of methanol extracts of Hericium erinaceus, Hericium americanum and Hericium coralloides, including free radical scavenging method (DPPH), ferric reducing antioxidant power (FRAP) and radical cation scavenging method (ABTS). Hericium spp exhibited moderate to high antioxidant activity. The highest TPC (3.27 ±0.01 mg GAE g–1) and antioxidant activity values (17.0 ±0.68 mmol TE g‒1 in FRAP; EC50 = 4.12 ±0.12 mg mL‒1 in DPPH•; EC50 = 2.83 ± 0.10 mg mL‒1 in ABTS•+) were found for methanol extracts of H. coralloides. The TPC and antioxidant activity of H. erinaceus isolates varied from strain to strain. H. americanum possessed considerably lower total phenolic content (2.31 ±0.01 mg GAE g‒1) and antioxidant activity (10.5 ±0.59 mmol TE g‒1 in FRAP; EC50 = 7.82 ±0.09 mg mL‒1 in DPPH•; EC50 = 6.36 ± 0.12 mg mL‒1 in ABTS•+) than H. coralloides and H. erinaceus. A high correlation was determined between TPC and ABTS•+ (r2 = 0.855), DPPH• (r2 = 0.969) and FRAP (r2 = 0.942). According to results obtained in the present study, Hericium spp., especially H. coralloides and some of H. erinaceus isolates, might be promising natural source of antioxidants for food and pharmaceutical industry.


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