Effect of Microwave Technology on Some Quality Parameters and Sensory Attributes of Black Tea

Although the quality of black tea mainly depends on the constituents and conditions of raw material, the manufacturing process also plays a significant role in obtaining high quality tea products. In this study, microwave technology is used for black tea production in withering and drying steps to increase its quality characteristics. Total polyphenols, theaflavin (TF), total thearubigins (TR), liquor brightness, and total colour were measured by spectrophotometric methods. Total antioxidant activity was determined by the DPPH method. Microwaved black teas showed higher amounts of quality constituents with similar phenolic contents and antioxidant activities compared to commercial Turkish teas. The plucking season was also found to have an effect on these constituents of black teas. Generally, microvawed black teas have higher spectrophotometric brightness and lower total colour values. The analytical and sensory results showed that using a microwave dryer during the black tea process is highly acceptable in respect to these quality parameters when compared with other commercial black teas obtained from the markets in Turkey and other countries.

Download Full-text

Effect of Fertilisation on the Quality of Dried Coriander (Coriandrum sativum L.) and Lovage (Levisticum officinale)

Agriculture ◽

10.3390/agriculture11050386 ◽

2021 ◽

Vol 11 (5) ◽

pp. 386

Author(s):

Natalia Matłok ◽

Józef Gorzelany ◽

Adam Figiel ◽

Maciej Balawejder

Keyword(s):

Bioactive Compounds ◽

Crop Production ◽

Solid Phase ◽

Quality Parameters ◽

Raw Material ◽

Vacuum Microwave ◽

Dpph Method ◽

Total Antioxidant ◽

Total Antioxidant Potential

The study presents the effects of fertilisation on selected quality parameters of the dried material obtained from plants of lovage and coriander. During the crop production process, the plants were treated with two fertilisers containing substances potentially acting as elicitors. The dried material was obtained in course of a drying process carried out in optimum conditions and based on the CD-VMFD method which combines convective pre-drying (CD) at a low temperature (40 °C) with vacuum-microwave finish drying with the use of 240 W microwaves (VMFD). The quality of the dried material was evaluated through measurement of the total contents of polyphenols, total antioxidant potential (ABTS and DPPH method), and the profile of volatile compounds (headspace-solid phase microextractio-HS-SPME) as well as assessment of the colour. It was found that by applying first fertilisation (with organic components) it is possible to significantly increase the contents of both bioactive compounds and volatile substances responsible for the aroma. It was determined that the higher content of bioactive compounds was related to the composition of the first fertiliser, presumably the extract from common nettle. The study showed that the application of the first fertiliser contributed to enhanced quality parameters of the raw material obtained.

Download Full-text

Evaluation of phenolic compounds and antioxidant activity in some edible flowers

Open Agriculture ◽

10.1515/opag-2020-0087 ◽

2020 ◽

Vol 5 (1) ◽

pp. 857-870

Author(s):

Fernando Gonçalves ◽

João Carlos Gonçalves ◽

Ana Cristina Ferrão ◽

Paula Correia ◽

Raquel P. F. Guiné

Keyword(s):

Antioxidant Activity ◽

Total Phenolics ◽

Total Phenolic ◽

Potential Health ◽

Phenolic Contents ◽

Spectrophotometric Methods ◽

Potential Source ◽

Successive Extraction ◽

Dpph Method ◽

Total Anthocyanins

AbstractRecently, edible flowers (EF) have aroused increased interest because of their aesthetic properties as well as potential health benefits related to the occurrence of some bioactive compounds. Therefore, the aim of this work was to evaluate the total phenolics, anthocyanins, flavonoids, and antioxidant activity (AOA) (following DPPH and ABTS methods) in eleven EF. The samples were subjected to three successive extraction steps using methanol, and these extracts were then analysed for the aforementioned properties using spectrophotometric methods. The obtained extracts were used for the quantification of phenolic composition and AOA. The results indicated that, among the flowers analysed in this study, red rose, pink rose, and red carnation possessed the highest total phenolic contents (27.53, 23.30, and 18.17 mg g−1 gallic acid equivalents, respectively), total anthocyanins (3.07, 1.97, and 4.47 mg g−1 catechin equivalents [CE], respectively), and AOA (12.07, 15.77, and 12.93 mg g−1 TE, respectively, as given by the DPPH method or 8.23, 9.27 and 8.00 mg g−1 TE, respectively, as given by the ABTS method). The flowers with highest flavonoids contents were red carnation, Mexican marigold, and pink rose (17.50, 16.90, and 16.57 mg g−1 CE, respectively). Cluster analysis grouped the analysed flowers into two groups, those richest in phenolics with AOA and those not so rich. Finally, some important correlations were observed between the total phenolics and the AOA. In conclusion, these flowers could represent a potential source of natural compounds with antioxidant capacity.

Download Full-text

Some Heavy Metals Correlated Negatively with Total Antioxidant Capacity, Glutathione Peroxidase, Fructose, and Testosterone in Seminal Plasma of Oligospermic and Azoospermic Males

Journal of Advances in Medical and Pharmaceutical Sciences ◽

10.9734/jamps/2021/v23i530235 ◽

2021 ◽

pp. 15-27

Author(s):

Edidiong Peter Umoinyang ◽

Ibioku Elekima ◽

Donatus Onwuli

Keyword(s):

Heavy Metals ◽

Seminal Plasma ◽

Antioxidant Activities ◽

Medical Laboratory ◽

Cross Sectional ◽

Medical Laboratory Science ◽

Spectrophotometric Methods ◽

Total Antioxidant ◽

Antioxidant Parameters ◽

Essential Heavy Metal

Aim: The study aimed to investigate the relationship between some heavy metals and total antioxidant capacities, glutathione levels, fructose, and testosterone in seminal plasma of infertile azoospermic and oligospermic males in Akwa Ibom State of Nigeria. Study Design: A cross-sectional design with a total of 124 males included in the study of which 32 were azoospermic, 38, oligospermic, and 54, normospermic. Place and Duration of Study: Semen samples were collected from the urology or fertility clinic of UUTH, St. Luke’s Hospital, Anua, and Ibom specialist hospital of Akwa Ibom State. However, laboratory assays were performed at the Department of Medical Laboratory Science, Rivers State University, Port Harcourt between May, 2018 and January, 2021. Methodology: Semen specimens were collected after 3-5 days abstinence according to WHO criteria while seminal plasma were obtained from semen by spinning at 4500 rpm for 10 minutes and stored at -700C prior to laboratory analysis. Atomic absorption spectrometer (AAS) was used to determine the levels of heavy metals while ELISA methods were used to determine testosterone and GSH concentrations. TAC and fructose assays were carried out using spectrophotometric methods. Results: Results showed that non-essential heavy metals such as lead, mercury, and arsenic correlated negatively with testosterone, fructose, and antioxidant activities of the seminal plasma in azoospermic subjects. In addition, lead and mercury correlated positively in the azoospermic subjects. Meanwhile, selenium, an essential heavy metal, correlated positively with testosterone and antioxidant activities in oligospermic subjects with 11-19 x106cells/ml. Conclusion: The levels of non-essential heavy metals in azoospermic subjects precipitated poor anti-oxidant and testosterone activities inducing oxidative stress while in oligospermic subjects, selenium and antioxidant parameters and testosterone were in good association indicating improved antioxidant activities and testicular function.

Download Full-text

Effect of Seasonal Variations and Growth Conditions on Carbohydrate Partitioning in Different Organs and the Quality of Bush Tea

HortScience ◽

10.21273/hortsci12972-18 ◽

2018 ◽

Vol 53 (7) ◽

pp. 999-1005

Author(s):

Mudau N. Fhatuwani ◽

Makunga P. Nokwanda

Keyword(s):

Antioxidant Activities ◽

Block Design ◽

Principal Component ◽

Quality Parameters ◽

The Other ◽

Glucose Content ◽

Antioxidant Power ◽

Significant Difference ◽

Total Antioxidant ◽

Growing Conditions

Bush tea (Athrixia phylicoides DC.) is a root perennial shrub used as indigenous tea and medicinal tea in South Africa. Thus, concurrent trials were conducted under different growing conditions as follows: in the glasshouse, field planted and wild, naturally grown, to investigate the effects of seasonal harvests and growing environments on carbohydrate reserves and quality parameters of bush tea. Of 50 plants, 25 single plants were allotted to each respective environment in a field and glasshouse conditions—and were arranged in a randomized complete block design. These were then harvested in summer, autumn, winter, and spring, respectively. For the wild bush tea trial, 25 single plants were randomly selected. Selected sugars and starch were quantified together with other quality parameters [total polyphenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), and total antioxidant activities). The study revealed that the glucose content of bush tea plant organs was significantly higher during winter, followed by autumn, as compared with the other seasons. Similar fructose and sucrose trends were evident. However, the content of amylopectin was also significantly higher during summer, followed by autumn, compared with the other seasons. In winter, plants exhibited higher amylopectin content when compared with other seasons. No significant differences were found in the amylose content. Both wild and cultivated bush tea plants yielded the highest specific sugars in the study. The phytochemicals present in the leaves of field-grown bush tea and wild bush tea during winter were higher than in those grown in summer, autumn, and spring. No significant difference in tannin contents was observed, irrespective of seasons and growing conditions. Regardless of growing conditions, autumn yielded lower total antioxidant activities using both the DPPH and ferric reducing antioxidant power (FRAP) assays when compared with other seasons. To better resolve the metabolomic data, principal component analysis (PCA) was used and the first principal component showed a strong correlation within all parameters recorded over PC2. Future ecophysiological studies are recommended to establish region- and season-specific metabolomic biomarkers with canonical distinction on beverage, pharmacological, and organoleptic attributes of bush teas.

Download Full-text

Urinary excretion of L-carnitine, acetyl-L-carnitine, propionyl-L-carnitine and their antioxidant activities after single dose administration of L-carnitine in healthy subjects

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502013000100020 ◽

2013 ◽

Vol 49 (1) ◽

pp. 185-191 ◽

Cited By ~ 1

Author(s):

Yu Cao ◽

Chuan-ji Hao ◽

Chen-jing Wang ◽

Peng-li Li ◽

Le-xin Wang ◽

...

Keyword(s):

Single Dose ◽

Healthy Subjects ◽

Antioxidant Activities ◽

Gradual Increase ◽

Urine Concentration ◽

Dose Administration ◽

Spectrophotometric Methods ◽

Total Antioxidant ◽

Urine Concentrations ◽

Total Antioxidative Capacity

The urine excretion of L-carnitine (LC), acetyl-L-carnitine (ALC) and propionyl-Lcarnitine (PLC) and their relations with the antioxidant activities are presently unknown. Liquid L-carnitine (2.0 g) was administered orally as a single dose in 12 healthy subjects. Urine concentrations of LC, ALC and PLC were detected by HPLC. Superoxide dismutase (SOD), total antioxidative capacity (T-AOC), malondialdehyde (MDA) and nitrogen monoxidum (NO) activities were measured by spectrophotometric methods. The 0~2 h, 2~4 h, 4~8 h, 8~12 h, 12~24 h excretion of LC was 53.13±31.36 µmol, 166.93±76.87 µmol, 219.92±76.30 µmol, 100.48±23.89 µmol, 72.07±25.77 µmol, respectively. The excretion of ALC was 29.70±14.43 µmol, 80.59±32.70 µmol, 109.85±49.21 µmol, 58.65±18.55 µmol, and 80.43±35.44 µmol, respectively. The urine concentration of PLC was 6.63±4.50 µmol, 15.33±12.59 µmol, 15.46±6.26 µmol, 13.41±11.66 µmol and 9.67±7.92 µmol, respectively. The accumulated excretion rate of LC was 6.1% within 24h after its administration. There was also an increase in urine concentrations of SOD and T-AOC, and a decrease in NO and MDA. A positive correlation was found between urine concentrations of LC and SOD (r = 0.8277) or T-AOC (r = 0.9547), and a negative correlation was found between urine LC excretions and NO (r = -0.8575) or MDA (r = 0.7085). In conclusion, a single oral LC administration let to a gradual increase in urine L-carnitine excretion which was associated with an increase in urine antioxidant enzymes and the total antioxidant capacities. These data may be useful in designing therapeutic regimens of LC or its analogues in the future.

Download Full-text

Comparative Biochemical Analysis of Secondary Metabolites in Commonly Grown Legume Varieties

Legume Research - An International Journal ◽

10.18805/lr-4217 ◽

2019 ◽

Author(s):

Savita Rani ◽

Sukriti Nehra ◽

M Khabiruddin ◽

Shubham Lamba

Keyword(s):

Free Radical ◽

Secondary Metabolites ◽

Seed Coat ◽

Antioxidant Activities ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Total Phenolic ◽

Phenolic Contents ◽

Dpph Method ◽

Whole Seed

In this research study, quantitative determination of phytoconstituents in seed coat, dehusked raw dal, cooked dal and whole seed of locally grown pulses viz. pigeonpea, lentil, desi and kabuli chickpea, and ricebean was carried out. Among the four treatments of all the pulses, highest yield in methanol was found in ricebean. Total phenolic content (mg GAEg-1) varied from 1.72-103.62 in all of the extracts. Similarly, flavonoids (mg CAEg-1) ranged from 1.13 to 33.66 which also found to be reduced in dehulled and cooked extracts. o-Dihydric phenols, hydrophobic and hydrophilic phenols followed order as: seed coat> whole seed> raw dal> cooked dal. Results obtained by DPPH method showed that free radical scavenging capacities ranged from 53.80 to 92.00% while antioxidant activity ranged from 51.00 to 78.60% by FTC method. A highly significant correlation (plessthan0.05) between antioxidant activities/free radical scavenging efficiencies and phenolic contents as well as flavonoids was observed in most of the extracts under study. The results concluded that the pulse seed extracts may be valuable natural source of secondary metabolites for nutraceutical industry.

Download Full-text

ANTIOXIDANT ACTIVITIES FROM VARIOUS EXTRACTS OF DIFFERENT PARTS OF KELAKAI (STENOCHLAENA PALUSTRIS) GROWN IN CENTRAL KALIMANTAN - INDONESIA

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2016.v9s2.13630 ◽

2016 ◽

pp. 215 ◽

Cited By ~ 1

Author(s):

Irda Fidrianny ◽

Siti Kusmardiyani ◽

Grace Novita

Keyword(s):

Antioxidant Activities ◽

Carotenoid Content ◽

Total Phenolic ◽

Root Extract ◽

Antioxidant Power ◽

Phenolic Contents ◽

Dpph Method ◽

Young Leaves ◽

Ferric Reducing Antioxidant Power ◽

Different Parts

ABSTRACT Objectives: The aims of this research were to determine antioxidant activity from various extracts of different parts of kelakai (Stenochlaena palustris [Burm.f.] Bedd) using two antioxidant testing methods, which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP), and correlation of total phenolic contents (TPC), total flavonoid contents (TFC), and total carotenoid contents (TCC) with their inhibitory concentration 50% (IC 50 ) of DPPH and exhibitory concentration 50% (EC 50 ) of FRAP. Methods: Sample was extracted by reflux using different polarity solvents. The extracts were evaporated using vacuum rotary evaporator. Antioxidant activities were tested using DPPH and FRAP assays, determination of TPC, TFC, and TCC was carried out by ultraviolet-visible spectrophotometry, and correlation with their IC 50 of DPPH and EC 50 of FRAP capacities was analyzed by Pearson’s method. Results: Ethanolic root extract of kelakai (S. palustris) had the lowest IC 50 of DPPH scavenging activity 0.8 µg/ml and the lowest EC of FRAP capacity 5.4 µg/ml. Ethanolic kelakai root extract demonstrated the highest phenolic content, ethyl acetate young leaves extract had the highest flavonoid content, and the highest carotenoid content was given by n-hexane root extract. There was significantly negative correlation between TPC in root extract of kelakai with their IC 50 of DPPH and EC 50 of FRAP. Conclusions: All different extracts of kelakai parts were categorized as very strong antioxidants by DPPH method. Phenolic compounds in kelakai root extract were the major contributor in antioxidant activities by DPPH and FRAP methods. DPPH and FRAP showed linear results in antioxidant activities of root kelakai extract. Keywords: Antioxidant, 2,2-diphenyl-1-picrylhydrazyl, Ferric reducing antioxidant power, Stenochlaena palustris, Young leaves, Old leaves, Root. 50

Download Full-text

Fermentation with Tea Residues Enhances Antioxidant Activities and Polyphenol Contents in Kombucha Beverages

Antioxidants ◽

10.3390/antiox11010155 ◽

2022 ◽

Vol 11 (1) ◽

pp. 155

Author(s):

Dan-Dan Zhou ◽

Adila Saimaiti ◽

Min Luo ◽

Si-Yu Huang ◽

Ruo-Gu Xiong ◽

...

Keyword(s):

Green Tea ◽

High Performance ◽

Antioxidant Activities ◽

Black Tea ◽

Trolox Equivalent Antioxidant Capacity ◽

Total Phenolic ◽

Array Detector ◽

Antioxidant Power ◽

Phenolic Contents ◽

Trolox Equivalent

Kombucha is a popular beverage with various bioactivities (such as antioxidant activity), which can be attributed to its abundant bioactive compounds, especially polyphenols. Kombucha is conventionally prepared by fermentation of a sugared black tea infusion without tea residue. In this study, the effects of black tea residue and green tea residue on kombucha were studied, and its antioxidant activities, total phenolic contents, as well as concentrations of polyphenols at different fermentation stages were evaluated using ferric-reducing antioxidant power, Trolox equivalent antioxidant capacity, Folin-Ciocalteu method and high-performance liquid chromatography with a photodiode array detector. The results showed that fermentation with tea residue could markedly increase antioxidant activities (maximum 3.25 times) as well as polyphenolic concentrations (5.68 times) of kombucha. In addition, green tea residue showed a stronger effect than black tea residue. Overall, it is interesting to find that fermentation with tea residues could be a better strategy to produce polyphenol-rich kombucha beverages.

Download Full-text

In Vitro Screening of Natural Drug Potentials for Mass Production

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha45110397 ◽

2017 ◽

Vol 45 (1) ◽

pp. 292-300 ◽

Cited By ~ 1

Author(s):

Gülsüm YALDIZ ◽

Ufuk KOCA ÇALIŞKAN ◽

Ceylan AKA

Keyword(s):

Antioxidant Activities ◽

Total Phenolic ◽

Equisetum Arvense ◽

Mineral Contents ◽

Phenolic Contents ◽

Methanolic Extracts ◽

Tanacetum Parthenium ◽

Plant Samples ◽

Total Antioxidant ◽

Usnea Longissima

Methanolic extracts of 16 plant species, used in herbal and traditional medicinal preparations, collected from the same geographic region (Golcuk-Seben/Bolu, Turkey) were evaluated for their relative total phenolic contents, total antioxidant activities and their mineral contents in both dried plant samples and methanolic extracts. These species included Hypericum perforatum L., Thymus sipyleus Boiss., Equisetum arvense L., Achillea millefolium L., Tanacetum parthenium L., Thymus leucostomus Hausskn. & Velen., Usnea longissima, Herniaria incana Boiss., Teucrium polium L., Stachys bithynica Boiss., Anthemis nobilis L., Sambucus ebulus L., Berberis vulgaris L., Malus communis Desf., Matricaria chamomilla L. and Scorzonera laciniata L. Spectrophotometric Folin-Ciocalteu and DPPH free radical scavenging activity methods were performed to detect the total phenolic contents and total antioxidant activities of the methanolic extracts, respectively. The results show that the fruits of Berberis vulgaris L., have the highest antioxidant activity and aerial parts of Tanacetum parthenium L. have the highest total phenolics (92.62%). Mineral contents were determined by inductively coupled – mass spectrometry (ICP-MS). All dried plant samples and methanolic extracts contained high amounts of Si, Cu, Fe and Ca. The highest levels of Si, Cu, Fe and Ca were found in Equisetum arvense L., Anthemis nobilis L., and Thymus sipyleus Boiss. dried plant samples, whereas Se was only detected in Usnea longissima. The highest levels of Si, Cu, Fe and Ca were found in the methanolic extracts of Usnea longissima, Anthemis nobilis L. and Thymus sipyleus Boiss. respectively.

Download Full-text

ANTIOXIDANT ACTIVITY AND PHENOLIC CONTENTS OF SEVEN BROWN SEAWEED FROM DJIBOUTI COAST

International Journal of Current Pharmaceutical Research ◽

10.22159/ijcpr.2019v11i3.34095 ◽

2019 ◽

pp. 42-44

Author(s):

ABDIRAHMAN ELMI FOURREH ◽

FATOUMA MOHAMED ABDOUL-LATIF ◽

MOUSTAPHA NOUR IBRAHIM ◽

ALI MERITO ALI

Keyword(s):

Antioxidant Activity ◽

Secondary Metabolites ◽

Dry Matter ◽

Phenolic Content ◽

Antioxidant Activities ◽

Biological Activities ◽

Brown Seaweed ◽

Antioxidant Potential ◽

Phenolic Contents ◽

Dpph Method

Objective: This study focuses on the antioxidant potential of Djibouti brown seaweed and their phenolic contents. Methods: We evaluated the antioxidant potential by DPPH method (1,1-diphenyl-2-picrylhydrazyl) and their phenolic contents of seven Djibouti seaweed: Cytoseira myrica, Padina pavonica, Sargassum fluitans, Sargassum ilifolium, Sargassum sp, Turbinaria triquetra and Turbinaria turbinata. Also, we searched the secondary metabolites of these seaweeds. Results: We obtain a higher antioxidant activity at 60,7±0,9 % and a higher phenolic content at 199,01±0,5 μg equivalent phloroglucinol (PGE)/g dry matter for Padina pavonica. A good linear correlation (R2 = 0,898) is observed between the antioxidant activity and the phenolic content of the seaweed studied. Also, two Padina pavonica collected in two different locations have different biochemical concentrations and antioxidant activity, suggesting the influence of the marine environment on the biosynthesis of secondary metabolites and the biological activities of seaweed. The present study shows the presence of tannins, saponosides, flavonoids and steroid-terpenes. Conclusion: The species studied show interesting antioxidant activities and can be consumed to prevent oxidative stress.

Download Full-text