scholarly journals Effects of Pretreatments and Drying Temperatures on Drying Characteristics, Antioxidant Properties and Color of Ginger Slice

Author(s):  
Ratiya Thuwapanichayanan ◽  
Charotorn Phowong ◽  
Donludee Jaisut ◽  
Jiří Štencl

To reduce the adverse effects of hot air drying, ginger slices were pretreated prior to drying. The effects of 2 pretreatment methods (blanching versus dipping in 0.1% ascorbic acid solution) and drying temperatures (60, 70 and 80 °C) on the drying characteristics and the qualities of the dried ginger slices in terms of total phenolic content (TPC), antioxidant activities (DPPH and ABTS methods) and color were investigated. It was noted that the moisture content for both un-pretreated and pretreated samples decreased more rapidly when drying was performed at higher drying temperatures. However, the drying time of un-pretreated and pretreated samples was not significantly different. The TPC and antioxidant activities of the ginger slices increased markedly after drying. The increase in these values was higher for pretreated samples. The dried ascorbic acid solution dipped sample exhibited the highest values of TPC and antioxidant activity. Moreover, the total color difference of the ascorbic acid solution dipped ginger was slightly lower than the total color difference of the un-pretreated ginger. However, the tested drying temperatures, ranging from 60 to 80 °C, did not affect the final TPC, antioxidant activities, and color of the ginger samples.

2009 ◽  
Vol 6 (2) ◽  
pp. 227-231 ◽  
Author(s):  
S. A. Adesegun ◽  
A. Fajana ◽  
C. I. Orabueze ◽  
H. A. B. Coker

The antioxidant activities of crude extract ofPhaulopsis fascisepalaleaf were evaluated and compared with α-tocopherol and BHT as synthetic antioxidants and ascorbic acid as natural-based antioxidant.In vitro, we studied its antioxidative activities, radical-scavenging effects, Fe2+-chelating ability and reducing power. The total phenolic content was determined and expressed in gallic acid equivalent. The extract showed variable activities in all of thesein vitrotests. The antioxidant effect ofP. fascisepalawas strongly dose dependent, increased with increasing leaf extract dose and then leveled off with further increase in extract dose. Compared to other antioxidants used in the study, α-Tocopherol, ascorbic acid and BHT,P. fascisepalaleaf extract showed less scavenging effect on α,α,-diphenyl-β-picrylhydrazyl (DPPH) radical and less reducing power on Fe3+/ferricyanide complex but better Fe2+-chelating ability. These results revealed thein vitroantioxidant activity ofP.fascisepala.Further investigations are necessary to verify these activitiesin vivo.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. S. Prasedya ◽  
A. Frediansyah ◽  
N. W. R. Martyasari ◽  
B. K. Ilhami ◽  
A. S. Abidin ◽  
...  

AbstractSample particle size is an important parameter in the solid–liquid extraction system of natural products for obtaining their bioactive compounds. This study evaluates the effect of sample particle size on the phytochemical composition and antioxidant activity of brown macroalgae Sargassum cristaefolium. The crude ethanol extract was extracted from dried powders of S.cristeafolium with various particle sizes (> 4000 µm, > 250 µm, > 125 µm, > 45 µm, and < 45 µm). The ethanolic extracts of S.cristaefolium were analysed for Total Phenolic Content (TPC), Total Flavonoid Content (TFC), phenolic compound concentration and antioxidant activities. The extract yield and phytochemical composition were more abundant in smaller particle sizes. Furthermore, the TPC (14.19 ± 2.08 mg GAE/g extract to 43.27 ± 2.56 mg GAE/g extract) and TFC (9.6 ± 1.8 mg QE/g extract to 70.27 ± 3.59 mg QE/g extract) values also significantly increased as particle sizes decreased. In addition, phenolic compounds epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and Epigallocatechin gallate (EGCG) concentration were frequently increased in samples of smaller particle sizes based on two-way ANOVA and Tukey’s multiple comparison analysis. These results correlate with the significantly stronger antioxidant activity in samples with smaller particle sizes. The smallest particle size (< 45 µm) demonstrated the strongest antioxidant activity based on DPPH, ABTS, hydroxyl assay and FRAP. In addition, ramp function graph evaluates the desired particle size for maximum phytochemical composition and antioxidant activity is 44 µm. In conclusion, current results show the importance of particle size reduction of macroalgae samples to increase the effectivity of its biological activity.


2013 ◽  
Vol 41 (1) ◽  
pp. 136 ◽  
Author(s):  
Violeta NOUR ◽  
Ion TRANDAFIR ◽  
Mira E. IONICA

Ten indeterminate tomato cultivars differing in fruit shape and typology, grown simultaneously in a greenhouse from Oltenia (Southwestern Romania) and harvested at red ripe stage, were investigated for the contents in ascorbic acid, lycopene, β-carotene, total phenolics, minerals (K, Na, Ca and Mg) and trace elements (Fe, Cu, Mn, Cr, Zn and B). In addition, their antioxidant activities were determined. Significant differences were found among tomato cultivars in all studied antioxidant compounds, as well as in the antioxidant activity. Ascorbic acid ranged from 91.9 to 329.7 mg kg-1 fw, lycopene ranged from 19.7 to 49.0 mg kg-1 fw, while total phenolic compounds varied between 300.2 and 557.8 mg kg-1 fw. Antioxidant activity ranged from 0.81 mmol Trolox kg-1 fw to 1.74 mmol Trolox kg-1 fw and it was significantly correlated to total phenolics content (r = 0.91; p< 0.05). The cocktail type cultivar ‘Tiger’ and the cherry type cultivar ‘Belle’ proved to be the most powerful in antioxidant activity and phenolic compounds while the rectangular plum shaped cultivar ‘Porto’ recorded the highest average lycopene content. A valuable cultivar proved to be the brownish red ‘Sacher’ which registered among the highest contents of phenolics, lycopene and ascorbic acid. Mineral and trace elements contents were also significantly affected by cultivars. Values recorded for K, Ca and Mg ranged from 2139.6 to 3056.9 mg kg-1, 137.7 to 325.8 mg kg-1 and 27.3 to 168.7 mg kg-1 respectively.


Author(s):  
Irda Fidrianny ◽  
Nadia Ilham ◽  
Rika Hartati

Objectives: The goals of this research were to observe antioxidant properties from different parts of super red dragon fruit (Hylocereus costaricensis) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS).Methods: Antioxidant activities were determined using DPPH and ABTS assays, total phenolic content (TPC) using Folin–Ciocalteu reagent, flavonoid content by Chang’s method.Results: Inhibitory concentration 50% (IC50) of DPPH scavenging activity of all of the extracts in the range of 2.69 μg/ml was −94.17 μg/ml. The ethyl acetate peel extract of super red dragon fruit expressed the highest TPC (4.56 g GAE/100 g) and the highest total flavonoid content (12.63 g QE/100 g). TPC in flesh extract of super red dragon fruit had a negative and significant correlation with their IC50 of ABTS. The IC50 of DPPH and IC50 of ABTS of flesh extract of super red dragon fruit showed positive and significant correlation.Conclusion: All different parts extracts of super red dragon fruit (except n-hexane flesh extract) were categorized as a very strong antioxidant by DPPH method. Phenolic compounds in flesh extract of super red dragon fruit were the major contributor in antioxidant activities by ABTS method. DPPH and ABTS showed linear results in antioxidant activities of super red dragon fruit flesh extract.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1761
Author(s):  
Moeun Lee ◽  
Jung Hee Song ◽  
Eun Ji Choi ◽  
Ye-Rang Yun ◽  
Ki Won Lee ◽  
...  

This study aims to investigate fermentative metabolites in probiotic vegetable juice from four crop varieties (Brassica oleracea var. capitata, B. oleracea var. italica, Daucus carota L., and Beta vulgaris) and their antioxidant properties. Vegetable juice was inoculated with two lactic acid bacteria (LAB) (Companilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124) isolated from kimchi and their properties were evaluated using untargeted UPLC-QTOF-MS/MS and GC-MS. The samples were also evaluated for radical (DPPH• and OH•) scavenging activities, lipid peroxidation, and ferric-reducing antioxidant power. The fermented vegetable juices exhibited high antioxidant activities and increased amounts of total phenolic compounds. Fifteen compounds and thirty-two volatiles were identified using UPLC-QTOF-MS/MS and GC-MS, respectively. LAB fermentation significantly increased the contents of d-leucic acid, indole-3-lactic acid, 3-phenyllactic acid, pyroglutamic acid, γ-aminobutyric acid, and gluconic acid. These six metabolites showed a positive correlation with antioxidant properties. Thus, vegetable juices fermented with WiKim39 and WiKim0124 can be considered as novel bioactive health-promoting sources.


Author(s):  
M. Suleman Stephen ◽  
E. A. Adelakun ◽  
J. H. Kanus ◽  
Meshack M. Gideon

The presence of natural antioxidant in plants is well known. Plant phenolics constitute one of the major groups of components that act as antioxidant and free radical terminator. Hence, this study focused on investigating the antioxidant activity of Celery plant (Apium graveolens L). The fresh leaves were collected, crushed and extracted with ethanol and acetone by maceration. The radical scavenging properties of the extracts were determined by measuring changes in absorbance of DPPH radical at a wave lenght of 517 nm by UV and ascorbic acid is used as the standard. It showed that the crude ethanolic extract has higher antioxidant activity compared to ascorbic acid and acetone extract with less scavenging activity. The values were (IC50 114.6 µg/mL) for ascorbic acid, (IC50 112 µg/mL) for the crude ethanolic extract and (IC50172 µg/mL) for crude acetone extract. The result shows that Celery plant grown in Jos possess good antioxidant properties which may be linked to the presence of phenolics and flavonoids in the plant, which justifies its use as a medicinal plant. This can be further investigated for the isolation and identification of active compounds of medicinal utilities.


2019 ◽  
Vol 44 (3) ◽  
pp. 239-247
Author(s):  
Mbarka Hfaiedh ◽  
Dalel Brahmi ◽  
Mohamed Nizar Zourgui ◽  
Lazhar Zourgui

Environmental and occupational exposure to chromium compounds, especially hexavalent chromium, is widely recognized as potentially nephrotoxic in humans and animals. The present study aimed to assess the efficacy of cactus (Opuntia ficus-indica) against sodium dichromate-induced nephrotoxicity, oxidative stress, and genotoxicity. Cactus cladodes extract (CCE) was phytochemically studied and tested in vitro for its potential antioxidant activities. Additionally, the preventive effect of CCE against sodium dichromate-induced renal dysfunction in a Wistar rat model (24 rats) was evaluated. For this purpose, CCE at a dose of 100 mg/kg was orally administered, followed by 10 mg/kg sodium dichromate (intraperitoneal injection). After 40 days of treatment, the rats were sacrificed, and the kidneys were excised for histological, lipid peroxidation, and antioxidant enzyme analyses. The phenol, flavonoid, tannin, ascorbic acid, and carotenoid contents of CCE were considered to be important. Our analyses showed that 1 mL of CCE was equivalent to 982.5 ± 1.79 μg of gallic acid, 294.37 ± 0.84 μg of rutin, 234.78 ± 0.24 μg of catechin, 204.34 ± 1.53 μg of ascorbic acid, and 3.14 ± 0.51 μg of β-carotene. In vivo, pretreatment with CCE was found to provide significant protection against sodium dichromate-induced nephrotoxicity by inhibiting lipid peroxidation, preserving normal antioxidant activities, and protecting renal tissues from lesions and DNA damage. The nephroprotective potential of CCE against sodium dichromate toxicity might be due to its antioxidant properties.


Author(s):  
Hanagasaki Takashi ◽  

Luffa (Luffa cylindrica Roem.) is a popular vegetable in Okinawa, and it has abundant nutrients, including &gamma;-aminobutyric acid (GABA). We focused on GABA content in luffa, taking into consideration registering it as foods with functional claims in Japan. Besides, when selling cut luffa and frozen cut luffa at supermarkets, they are supposed to get browned due to air exposure and other causes. In the present study, we developed the prevention method of browning cut luffa and frozen cut luffa using 0.5 %, 1.0 %, 2.0 %, and 4.0 % ascorbic acid solution. It was found that 55 L of 4.0 % ascorbic acid solution could be used for soaking of 70 kg cut luffa to prevent browning, but GABA content decreased in food processing of luffa in the factory. Besides, GABA content in luffa fruits was found not to change during storage for 07 days at room temperature after harvest.


2019 ◽  
Vol 800 ◽  
pp. 60-64
Author(s):  
Fredijs Dimiņš ◽  
Ingrīda Augšpole

The aim of the study was to characterize antioxidative properties and antiradical activity of the herbal syrups collection in Latvia. Spectrophotometry was used to characterize antioxidant properties of herbal syrups. Antiradical activity, total phenols and content of flavonoids were determined spectrophotometrically. The antiradical scavenging activity was measured by the DPPH (2.2-diphenyl-1-picrylhydrazyl) reaction. The herbal syrups antiradical scavenging activity was estimated by the amount of DPPH of reagent using in reaction with a sample of vegetable syrup (in percent) and by Trolox equivalent. The total phenolic compounds were determined by using the Folin – Ciocalteu method. The total phenolic content was expressed in mg of the gallic acid equivalents. The content of flavonoids was determined by using reaction between the AlCl3 and flavonoids. Antiradical scavenging activity by Trolox equivalent of the herbal syrups was found from 81 to be 130 mg 100 g-1 herbal syrups. The content of total phenols was found from 22 to be 282 mg GAE 100 g-1, but content of total flavonoids by quercetin equivalent was found from 1 to 44 mg QE 100 g-1. In case of increased disease problems, syrups with increased antioxidant content should be used. However, the specificity of each disease should be taken into account as well as the content of certain compounds in the plants.


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