scholarly journals Effects of water stress on phenolic content and antioxidant activity of African nightshades

2017 ◽  
Vol 15 (2) ◽  
pp. 79-95 ◽  
Author(s):  
ODHIAMBO PETER OKELLO ◽  
JOSEPH P. ONYANGO GWEYI ◽  
MILDRED PAULINE NAWIRI ◽  
WINFRED MUSILA

Okello OP, Gweyi JPO, Nawiri Mp, Musila W. 2017. Effects of water stress on phenolic contents and antioxidant activity of African nightshades. Biofarmasi J Nat Prod Biochem 15: 79-95. This study aimed at mapping out the distribution of different African Nightshade species in Siaya and Kisii Counties of Kenya and to determine water stress effect on total antioxidant capacity and total phenolic content of two selected African nightshade namely, giant nightshade (Solanum scabrum) and black nightshade (Solanum villosum). Before selection of the two varieties, the study involved farmer field visits, mapping of nightshades present and administration of semi-structured questionnaires to farmers to determine the indigenous vegetables being grown, the nightshade species grown and factors affecting their production. The experiments were conducted both in the field and greenhouse conditions. Watering intervals were at 15 cbars, 50 cbars, and 85 cbars. Data on the number of secondary buds, leaf area, shoot height, shoot and root dry weights were gathered. The total antioxidant capacity and the total phenolic content were recorded using DPPH radical scavenging method and Folin-Ciolcalteu method, respectively. The data collected were subjected to ANOVA. In both counties where production was 100% under small scale, Solanum scabrum was the main variety grown is Siaya County (36%) while in Kisii the main variety was Solanum villosum (32%). There were significant differences (P≤0.05) among treatments in leaf area, plant height, shoot biomass, number of secondary buds, leaf and root total phenolic content and leaf and root antioxidant activity. At all stress levels, Solanum scabrum exhibited the tallest plants with a maximum height of 45.17cm at 15cbars, while Solanum villosum had the shortest plants at all stress levels, with the shortest one being recorded at 16.65 cm at 85 cbars. S. scabrum also had the highest root dry weight (7.78g), shoot dry weight (50.78g) and highest leaf area of (304.45cm2). However, Solanum villosum had the highest number of secondary buds at all stress levels with the highest being 24 at 15 cbars. Concerning phytochemicals, Solanum villosum had a higher concentration of both the total phenolics and antioxidant activity in the shoots (46.41g GAE/Kg DM total phenolic content and 52.68% total antioxidant activity). Meanwhile, Solanum scabrum had a higher concentration in the roots (25.06gGAE/Kg DM total phenolic content and 27.18% total antioxidant activity). Water stress cause a decline in all growth parameters but increased phytochemical accumulation in nightshade accessions grown. It is therefore suggested that for better yields, irrigation should be performed at every 15 cbars, however for adequate phytochemical accumulation, the irrigation should be carried out at 50 cbars. Further research to explore and quantify other phytochemical components as affected by different watering regimes need to be undertaken.

2021 ◽  
Vol 25 (2) ◽  
pp. 185-200
Author(s):  
Robert Socha ◽  
Justyna Kałwik ◽  
Lesław Juszczak

Abstract The purpose of this study was to determine phenolic profile and antioxidant activity of the selected edible flowers grown in Poland. A significant variation was observed in the both antioxidant activity and total phenolic content. Marigold flowers were characterized by the highest total phenolic content (89.22 mg GEA/g dry weight). In turn, begonia flowers exhibited the highest total flavonoids and phenolic acids content (21.96 mg QE/g dry weight, and 8.60 mg CAE/g dry weight, respectively). Taking into account the type of flowers, begonia and marigold flowers were the richest in phenolic acids. Caffeic and p-coumaric acids were the most frequent ones in the edible flowers grown in Poland. While gallic and p-coumaric acids were the prevalent ones in terms of their content. The begonia and marigold flowers contained quercetin and kaempferol, while hesperetin and naringenin were present in the chives flowers. The marigold flowers were characterized by a particularly high content of quercetin, and also exhibited the highest total antioxidant activity. The methanolic extracts of marigold and begonia flowers were characterized by the highest antioxidant activity, reducing activity, as well as the highest ability to neutralize free radicals.


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


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.


2019 ◽  
Vol 15 (11-12) ◽  
Author(s):  
Kashif Ghafoor ◽  
Isam A. Mohamed Ahmed ◽  
Süleyman Doğu ◽  
Nurhan Uslu ◽  
Gbemisola J. Fadimu ◽  
...  

AbstractThe effect of heating at different temperatures (60, 80, 90, 110, and 130 °C) on the total phenolic content, antioxidant activity, and phenolic compounds present in plum and mahaleb fruits was investigated. The antioxidant activity values and total phenolic contents of fresh plum (93.82% measured by DPPH method, 787.79 mg gallic acid equivalent (GAE)/100 g dry weight determined by Folin method) and mahaleb fruits (81.80%, 634.47 mg GAE/100 g dry weight) were higher than plum and mahaleb fruits dried at different temperatures (p < 0.05). Generally, the heating process caused a reduction in both total phenolic content and antioxidant activity for plum and mahaleb. While (+)-catechin (92.62 mg/kg), 1,2-dihydroxybenzene (132.15 mg/kg), gallic acid (107.01 mg/kg), and 3,4-dihydroxybenzoic acid (74.59 mg/kg) are the key phenolic compounds in fresh plum, (+)-catechin, 3,4-dihydroxybenzoic acid, 1,2-dihydroxybenzene, and syringic and caffeic acids were the major phenolic compounds of mahaleb fruits. The polyphenol content of fruits and the class of phenolics present are significantly affected by heating temperature.


2014 ◽  
Vol 32 (No. 6) ◽  
pp. 549-554 ◽  
Author(s):  
M.A. Fernández-León ◽  
M. Lozano ◽  
D. González ◽  
M.C. Ayuso ◽  
M.F. Fernández-León

The bioactive compounds, as well as the in vitro antioxidant activity of two Savoy cabbage cultivars, Dama and Leticia, grown in west of Spain under similar conditions were identified, quantified and compared. We found that cv. Dama presented in general betters results when compared with cv. Leticia. Cv. Dama presented higher concentrations of chlorophyll a (2.26 mg/100 g fresh weight), total phenolic content (102.71 mg of chlorogenic acid equivalent/100 g fresh weight) and total intact glucosinolates (195.22 &micro;mol of sinigrin equivalent/100 g fresh weight). Thus, cv. Dama exhibited higher values of in vitro antioxidant activity. &nbsp;


2013 ◽  
Vol 15 (4) ◽  
pp. 520-528 ◽  
Author(s):  
K.S. Farias ◽  
T.S.N. Santos ◽  
M.R.A.B. Paiva ◽  
S.M.L. Almeida ◽  
P.T. Guedes ◽  
...  

The purpose of this study was to screen the antioxidant activity of medicinal plant extracts from the Brazilian cerrado, through other methods than the total phenolic content and its correlation with the antioxidant activity. Ethanolic extracts of ten species were evaluated through three antioxidant assays, in vitro, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant activity and reducing power; and by using the Folin-Ciocalteu method the total phenolic content was determined. Ethanolic extracts of Stryphnodendron obovatum, Cecropia pachystachya and Duguetia furfuraceae showed strong antioxidant activity (IC50<5 µg mL-1) in the DPPH free radical scavenging assay; the species Vernonia phosphorea, Hymenaea stignocarpa and Jacaranda ulei may also be highlighted. These results were confirmed in the assays of total antioxidant capacity and reducing power. The extracts of S. obovatum and V. phosphorea showed an abundant phenolic content; therefore, the phenolic content may play a role in the antioxidant activity. These two species, traditionally used in Brazil, showed great power in these assay systems and may be a promising source for the development of natural antioxidants and future candidates for phytochemical and pharmacological studies in related diseases.


2007 ◽  
Vol 62 (1-2) ◽  
pp. 32-38 ◽  
Author(s):  
Renata Nowak ◽  
Urszula Gawlik-Dziki

Antioxidant potential of Rosa L. leaves methanolic extracts was evaluated in vitro using a spectrophotometric method based on measuring the radical scavenging effect on 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radicals. The contents of ellagic acid, quercetin and kaempferol in the extracts from leaves of seventeen rose species were determined using SPE-RPHPLC methods. Additionally, total phenolic content was determined spectrophotometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents (GAE). Remarkable high antioxidant activity and high total phenolic content (5.7% < GAE < 15.2%), large ellagic acid (EA) content from 9.37 to 19.42 mg/g of dry weight, a quercetin content ranging from 3.68 to 15.81 mg/g of dry weight and kaempferol content from 1.25 to 9.41mg/g of dry weight were found in rose leaves. Significant correlation between EA (r2 = 0.6131), quercetin (r2= 0.5158), total phenolic content (r2= 0.8485) and antioxidant activity was observed. Basing on the studies conducted one may assume that the extracts of rose leaves are a rich source of natural antioxidants and could be used to prevent free-radical-induced deleterious effects.


2006 ◽  
Vol 12 (5) ◽  
pp. 385-395 ◽  
Author(s):  
S. Silva ◽  
L. Gomes ◽  
F. Leitão ◽  
A. V. Coelho ◽  
L. Vilas Boas

Extracts of leaves, fruits and seeds of olive tree cultivars of Trás-os-Montes e Alto Douro (Portugal) were analysed by reverse phase HPLC with diode array detection and mass spectrometry (MS). This methodology allowed the identification of some common phenolic compounds, namely, verbascoside, rutin, luteolin-7-glucoside, oleuropein and hydroxytyrosol. Moreover the hyphenation of HPLC with MS enabled the identification of nüzhenide in olive seeds. An oleuropein glucoside was also detected in olive tree leaves. The total phenolic content was determined with the Folin Denis reagent and the total antioxidant activity with the ABTS method. There is a correlation between total antioxidant activity and total phenolic content with the exception of the seed extracts analysed. The apparent high antioxidant activity of seed extracts may be due to nüzhenide, a secoiridoid that is the major phenolic component of olive seeds. These results suggest a possible application of olive seeds as sources of natural antioxidants.


Author(s):  
Arkadiusz Szpicer ◽  
Anna Onopiuk ◽  
Iwona Wojtasik-Kalinowska ◽  
Andrzej Półtorak

AbstractConsumers are increasingly interested in innovative products enriched with nutrients that counteract the development of civilisation-associated diseases. Thus, the development of new functional nutrient-enriched food products that meet consumer needs is therefore necessary. The aims of this study were to develop a novel shortbread cookie product by addition of red grape skin extract and oat β-glucan and to evaluate the influence of these modifications on physico‐chemical properties and consumer’s acceptance. The red grape skin extract used in this product is a source of polyphenols which are beneficial for human health and extend product shelf life. β-glucan is a soluble fraction of dietary fibre that helps to lower reduce blood cholesterol and glycemic levels. The influence of grape skin extract, β-glucan and a combination of both on the β-glucan content, colour and texture parameters, thermal properties, total antioxidant activity, total phenolic content, volatile compounds profile and sensory properties of shortbread cookies was analysed. Product with modified formulations had higher total antioxidant activity, total phenolic content and were was more thermally stable than control samples. The obtained innovative functional products were characterized by an increased content of oat β-glucan, which is desirable from a nutritional point of view. The DSC measurements showed higher oxidative stability of cookies enriched with β-glucan and red grape skin extract. The additives caused significant changes in the colour and profile of volatile compounds of the finished final product but did not affect the sensory acceptance among consumers. The use of these additives represents a development in food technology that may be valuable in the food industry to increase the nutritional value and extend the shelf shelf-life of bakery products.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Vandana Dohre ◽  
Surabhi Yadav

To determine and compare total antioxidant activity (TAA) and phenolic content (TPC) of Sansevieria trifasciata leaves’ extract with different fruits’ extract (Guava, Indian plum and Indian gooseberry) and fruit juices (Pomelo, Orange, and Beetroot) on the basis of two extraction methods, total phenolic content and antioxidant activity were analysed by Folin-Ciocalteu’s and Phosphomolybdate assay, respectively and expressed as equivalent to catechin. The extraction process of selected samples was done by using both decoction extraction method (DEM) and microwave-assisted method (MAE) of water solvent. Among both techniques of extractions, MAE exhibited significantly higher TPC and TAA than DEM. Compared to Sansevieria trifasciata plant extracts, there was a strong positive correlation coefficient (á<0.05) between the total phenolic contents and antioxidant activities of different fruit juices and fruit extracts in both the classical (DEM) and modern (MAE) techniques. Sansevieria trifasciata possesses a considerable amount of phenolic compounds and antioxidant activity concerning different fruit juices and fruit extracts which directly associated with health-promoting potential and appears as possible drug development for antioxidant. Among all extract and juices, Indian gooseberry possesses the greatest total phenolic content and antioxidant activity due to its higher TPC.


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