scholarly journals The total phenolic contents and DPPH radical scavenging activities of Korean sweet potatoes according to plants parts, varieties, and by distribution and cooking methods

2013 ◽  
Vol 9 (2) ◽  
pp. 7-19
Author(s):  
정중근 ◽  
임효원
2020 ◽  
Vol 15 (1) ◽  
pp. 19-23
Author(s):  
Alican Bahadir Semerci ◽  
Dilek İnceçayır ◽  
Vusale Mammadova ◽  
Ayşegül Hoş ◽  
Kenan Tunç

The antibacterial and antifungal activities of the bulb and flower of Allium staticiforme and Allium subhirsutum were investigated. In addition, DPPH radical scavenging activity and total phenolic contents were determined. The results show that methanolic extracts of A. staticiforme and A. subhirsutum had antifungal activities against Candida albicans, together with a less activity level against Escherichia coli, Staphylococcus epidermidis, S. aureus, Enterecoccus faecalis, Salmonella typhimurium and Pseudomanas aeruginosa. The total phenolic contents of A. staticiforme leaf and bulb were determined as 17 and 2.4 mg of GAE/100 g, respectively. The IC50 of methanolic extracts of A. staticiforme and A. subhirsutum were also determined. In conclusion, both A. staticiforme and A. subhirsutum have antifungal activities with weak antibacterial activities. These plants have DPPH radical scavenging activities. Video Clip of Methodology: Disc Diffusion Method: 3 min 04 sec:  Full Screen   Alternate


2019 ◽  
Vol 3 (2) ◽  
pp. 66-72
Author(s):  

: The aim of the present study is to determine the total phenolic contents (TPC), DPPH radical scavenging activities, and reducing power of commercially consumed herbal teas including sage tea (ST), blackberry tea (BT), apple tea (AT), Echinacea tea (ET), lime tea (LT), rosehip tea (RT), and green tea (GT) in Turkey. For this purpose, various solvents were used for extraction of the tea samples and the results were compared in terms of total phenolic contents and antioxidant activities, as well. Hot water is found as the best solvent for the extraction of total phenolics from ST, BT, AT, and RT, respectively. On the other hand, the highest TPC values are obtained with the extraction of ET, LT, and GT in the presence of aqueous acetone (50%) solvent system. Generally all samples gave high DPPH radical scavenging activities depending on their extraction solvents. The highest radical scavenging activity was found as 94.92 ± 0.01 % for ST in ethanol, while the lowest activity was obtained as 5.98 ± 0.14 % for BT with water extract. Ferric reducing antioxidant assay results are closed each other and the highest activity (0.27 ± 0.74 mM Trolox) was observed in the ethanol extract of ST. Antioxidant activities and TPC of the herbal tea samples varied depending on the extraction solvent. Water or aqueous organic solvent extracts of sage tea and green tea samples gave high TPC values and antioxidant activities.


Antioxidants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 226 ◽  
Author(s):  
Mohammad Fikry ◽  
Yus Aniza Yusof ◽  
Alhussein M. Al-Awaadh ◽  
Russly Abdul Rahman ◽  
Nyuk Ling Chin ◽  
...  

Full-fat roasted date seeds are considered an excellent source of antioxidants which can treat many diseases. The specific objectives were to investigate the effect of roasting temperature and time on the hardness of whole seeds, moisture content of the roasted date seeds powder, DPPH radical scavenging activity, total phenolic contents, extraction yield, pH, browning index and sensory properties of the brew prepared from the full-fat roasted date seeds and to construct descriptive models that could describe this effect. Date seeds were roasted at three temperatures (160, 180 and 200 °C) for different period of times (10, 20 and 30 min) using a natural conventional oven; then grinded and next brewed. Hardness of whole seeds, moisture content of the seeds powder, DPPH radical scavenging activity and total phenolic contents, extraction yield, pH and browning index and sensory properties of the brew were significantly affected by the roasting conditions. The statistical results indicated that the proposed model could adequately describe the measured properties. Strong correlations have been found among the properties of the brew as well. The producers of the date seeds brew can utilize these results for controlling the roasting process.


Author(s):  
Bilge Taşkın ◽  
Neriman Bağdatlıoğlu

During conventional fermentation of milk into yogurt and kefir, changes of antioxidant capacities (DPPH radical scavenging, ferrous chelating, reducing power, hydrogen peroxide/ H2O2 scavenging activity) and total phenolic content were investigated. Both products showed greater phenolic content, DPPH radical scavenging, and reducing power activities than was the case of their unfermented milk forms. But they were unable to scavenge H2O2. Chelating ability of milk increased by yogurt fermentation but decreased by kefir fermentation. In general, antioxidative capacity of milk improved throughout conventional yogurt and kefir fermentations and ripening periods (except chelating ability for kefir and H2O2 scavenging). This study is valuable since it evaluates the antioxidant power of yogurt and kefir produced by traditional fermentation with 5 different antioxidative approaches. In face of rapidly rising consumer demand for safe, healthy, functional but natural foods, revealed results might strengthen importance of conventional fermentation process and highlight the antioxidative contributions of mentioned products


Author(s):  
Fadime Seyrekoğlu ◽  
Hasan Temiz

In this study, various extracts of Hypericum perforatum L. were investigated in terms of their extraction yields. For this purpose, five solvent systems including 70%EtOH-30% H2O (A), 50%EtOH-50% H2O (B), 30%EtOH-70% H2O (C), 100% EtOH (D), and 100% H2O (E) were used. Ultrasonic-assisted extraction was used for extraction and extraction processes were performed at different temperatures (30°-70oC) and extraction times (30-70 min.). The optimum extraction conditions for H. perforatum was determined based on extraction yield, total phenolic contents, and DPPH radical scavenging activities of the crude extracts, as well. The best ultrasound extraction conditions are achieved in the presence of 70%EtOH-30% H2O solvent system, for 40 min, at 30°C for H. perforatum.


2018 ◽  
Vol 6 (1) ◽  
pp. 13-17
Author(s):  
Babatunde Joseph Oso ◽  
Adenike Temidayo Oladiji

Most plant products undergo one or more different thermal processes before consumption despite the claims that cooking fruits and vegetables could have detrimental effects on the beneficial properties of the plants. This work investigated the changes in antioxidant status occurring in dried fruit of Xylopia aethiopica subjected to cooking at different temperatures. The analyses were performed on both raw and boiled samples to assess the total phenolic contents (TPCs) and the antioxidant potential through reduction of ferric chloride salt and bleaching of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The data obtained were subjected to analysis of variance and pairwise comparisons by Tukey-Kramer test at p < 0.05. There was a significant heat-trend difference between the phenolic contents of the samples at the selected temperatures with the highest TPC recorded at 70°C. Similarly, the ferric reducing potentials of the cooked samples were significantly different (p <0.05) from the raw. However, uncooked samples had significantly (p <0.05) higher percentage of DPPH radical scavenging activity compared to cooked samples. The overall effect of cooking the dried fruit of X. aethiopica was due to an elevation in total phenolics concentrations and reducing potentials of the aqueous infusions. However, boiling decreases the DPPH radical scavenging ability of the samples. Therefore, this study suggests an optimum cooking temperature of 70°C which could result in the highest retention of phenolic contents and ferric reducing potentials in the fruit of X. aethiopica and lowest appropriate temperature to conserve its intrinsic radical-scavenging activity in order to assure a higher quality food for the maintenance of human health. Moreover, losses in the phenolic contents and antioxidant potential should be considered when the procedural temperature during processing is unalterable.


2021 ◽  
Vol 19 (01) ◽  
pp. 137-142
Author(s):  
VIJAYA KUMAR GOPALAN NIRVESHA NAIR ◽  
SEOK TYUG TAN

Literature has consistently reported that horticultural wastes including leaves, skin, stones and seeds contain substantial amounts of bioactive compounds. Therefore, this study aims to evaluate antioxidant activity, Total Phenolic Content (TPC) and colour parameters in avocado, banana, and papaya leaves. Antioxidant activity of the leaves was determined using Trolox Equivalent Antioxidant Capacity (TEAC) and DPPH radical scavenging assays, whereas TPC was evaluated using Folin-Ciocalteu assay. Data analysis was carried out using SPSS version 25 of triplicate determinations. Mean differences among the fruit leaves extracts were determined using One way-ANOVA, while the correlations between the studied components were by the Pearson's Correlation Coefficient Test. The colour of the extracts was determined using a colour picker software. The TEAC values were in the range of 332.30 ± 18.04 µg Trolox/g D.W. (avocado leaves) to 12217.71 ± 18.04 µg Trolox/g D.W. (banana leaves) while the DPPH radical scavenging activity was from 10.07 ± 3.89% (banana leaves) to 86.70 ± 0.26 % (avocado leaves). Besides, TPC was from 871.33 ± 38.35 µg GAE/g D.W. (papaya leaves) to 1199.08 ± 6.00 µg GAE/g D.W. (avocado leaves). The hue values were from 19º in avocado leaves extract to 37º in banana leaves extract. Results from Pearson's Correlation Coefficient Test revealed that there were no significant correlations between the studied assays. Avocado leaves had the highest DPPH radical scavenging activity and TPC among the three extracts. Findings derived from the present study could be exploited in nutraceuticals formulation.


2012 ◽  
Vol 7 (2) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Laura Giamperi ◽  
Anahi Bucchini ◽  
Angela Bisio ◽  
Emanuela Giacomelli ◽  
Giovanni Romussi ◽  
...  

The total phenolic content and antioxidant activity of 6 Salvia spp. exudates were measured to find new potential sources of natural antioxidants. Total phenolic content was assessed by a modified Prussian blue method, and the antioxidant activity by two methods: 1,1- diphenyl-2-picryl- hydrazyl (DPPH) radical scavenging capacity assay and lipoxygenase inhibitory assay. The total phenolic content ranged between 1.3 μg/mg DW ( S. fallax) and 74.0 μg/mg DW ( S. cacaliaefolia). In the DPPH test, S. cacaliaefolia was more effective than BHT, while in the inhibition of lipid peroxidation all the extracts presented good antioxidant capacity.


2013 ◽  
Vol 8 (8) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Chahrazed Hamia ◽  
Nadhir Gourine ◽  
Hadjer Boussoussa ◽  
Mokhtar Saidi ◽  
Emile M. Gaydou ◽  
...  

The essential oil obtained by hydrodistillation of the flowers of Rhanterium adpressum Coss. & Durieu was analyzed using GC and GC-MS. The essential oil was very rich in monoterpene compounds. The major components identified were the monoterpene hydrocarbons: camphene (21.8%), myrcene (19.3%) and α-pinene (17.4%). Other compounds, including limonene, β-pinene and terpinol-4-ol, were present in low content (4–6%). The composition of the fatty acids in the lipid extract obtained from the flowers was also investigated by GC and GC-MS. The main fatty acids identified were palmitic (47.4%), oleic (12.9%) and stearic acids (10.6%). The total phenolic contents and the antioxidant activities were also evaluated for both extracts. The total phenolic contents were determined using the Folin-Ciocalteu reagent and the antioxidant activities were measured using three different assays: DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity, FRAP (ferric reducing antioxidant potential) and a molybdenum assay. As a result of these tests, the lipid extract exhibited the highest antioxidant activities in comparison with the essential oil extract.


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