Antioxidant power of phytochemicals fromPsidium guajavaleaf (original) (raw)
Related papers
2015
Antioxidants received from plant sources are found to be one of the best remedies for a number of human diseases. Guava with high amount of dietary fiber is recommended as natural and secured source of antioxidants. In this study, antioxidant capacity in guava fruits is determined by the assessment of total phenol content and DPPH scavenging activity. Results obtained emphasize on the usage guava fruits to eradicate destructive free radicals from the human body. Daily intake of guava fruits can help fighting noxious diseases like cancer and arthritis.
Food Chemistry, 2007
The ethanol extracts from 24 samples plant species commonly found in Thailand were investigated and compared on their antioxidant activity by ABTS assay. The ethanol extract from the leaves of guava (Psidium guajava) showed the highest antioxidant capacity with the TEAC value of 4.908 ± 0.050 mM/mg, followed by the fruit peels of rambutan (Nephelium lappaceum) and mangosteen (Garcinia mangostana) with the TEAC values of 3.074 ± 0.003 and 3.001 ± 0.016 mM/mg, respectively. The further investigation of guava leaf extracts from different solvents; n-hexane, ethyl acetate, n-butanol, and methanol, was examined using ABTS and FRAP assays. The total phenolic content was done by Folin-Ciocalteu reaction. The results indicated that the methanol fraction possessed the highest antioxidant activity, followed by the butanol and ethyl acetate fractions, respectively. The hexane fraction showed the lowest antioxidant activity. The results demonstrated that the mechanism of antioxidant action of guava leaf extracts was free radical scavenging and reducing of oxidized intermediates. The phenolic content in guava leaf fraction played a significant role on the antioxidant activity via reducing mechanisms.
Antioxidant power of phytochemicals from Psidium guajava leaf
JZUS-A - Journal of Zhejiang University. Science, 2004
Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 +/-15.5 and 511.6+/-6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH*) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH* color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the ...
The Scientific World Journal, 2020
Free radicals can cause many diseases, such as cancer. Antioxidant is a compound that could scavenge free radicals. One of the natural antioxidants is guava. The goals of this research were to investigate the antioxidant activity of leaves and fruit of crystal guava by determining the value of the Antioxidant Activity Index (AAI) using DPPH, CUPRAC, and FRAP; evaluate the total phenolic content (TPC) and total flavonoid content (TFC); analyse the correlation between the TPC and TFC with AAI DPPH, CUPRAC, and FRAP, and analyse the correlation between the 3 methods. Extraction was performed by the reflux method using n-hexane, ethyl acetate, and ethanol. Determination of AAI DPPH, CUPRAC, FRAP, the TPC, and the TFC was performed by UV-visible spectrophotometry. The correlation of the TPC and TFC with AAI DPPH, CUPRAC, and FRAP and, also, the correlation of the 3 methods were investigated by Pearson’s method. The antioxidant activity of leaves and fruit extracts of crystal guava showed...
Journal of Food Composition and Analysis, 2006
Guava fruit extracts were analyzed for antioxidant activity measured in methanol extract (AOAM), antioxidant activity measured in dichloromethane extract (AOAD), ascorbic acid, total phenolics, and total carotenoids contents. The ABTS, DPPH, and FRAP assays were used for determining both AOAM and AOAD, whereas the ORAC was used for determining only AOAM. Averaged AOAM [mM Trolox equivalent (TE)/g fresh mass (FM)] were 31.1, 25.2, 26.1, and 21.3 as determined by the ABTS, DPPH, FRAP, and ORAC assays, respectively. Averaged AOAD (mM TE/g FM) were 0.44, 0.27, and 0.16 as determined by the ABTS, DPPH, and FRAP assays, respectively. AOAM determined by all assays were well correlated with ascorbic acid (0.61prp0.92) and total phenolics (0.81prp0.97) and also among themselves (0.68prp0.97) but had negative correlation with total carotenoids (À0.67prpÀ0.81).
Flavonoid profile and antioxidant activity of pink guava
ScienceAsia, 2015
This article determines ascorbic acid, total phenolic content and the antioxidant capacity of whole fruit, flesh, and skin fractions of two varieties of pink guava widely produced in Malaysia (semenyih and sungkai). They were analysed and specific flavonoid compounds (apigenin, isorhamentin, kaempferol, luteolin, myricetin, and quercetin) were determined. Ascorbic acid, total phenolic content and antioxidant capacity was found to be higher in semenyih than in sungkai, mainly in the skin fraction. The predominant flavonoid in all pink guava fractions was kaempferol, with sungkai flesh having the highest kaempferol content. The pink guava represents an important source of antioxidant flavonoid compounds that may have health benefits.
Identifying Antioxidant Activities of Guava Fruit Using DPPH Method
Proceedings of the 1st International Conference on Community Health (ICCH 2019), 2020
Antioxidant plays an important role in preventing degenerative diseases. One of fruits that has a potential antioxidant activity is guava. This research was aim to identify antioxidant activity of guava fruit. Potential antioxidant compounds in guava were extracted using sonicator, as a green extraction technique. DPPH (2,2-diphenyl-1-picrylhydrazyl) was used to determine antioxidant activity. Vitamin C was used as a reference standard. The result showed that ethyl acetate extract of guava fruit has a high antioxidant activity. The presence of flavonoids, steroids, and tannins in ethyl acetate extract were predicted as a potential antioxidant compounds.
Quantification of bioactive compounds in guava at different ripening stages
Food Research, 2021
Guava (Psidium guajava L.) is one of the most important tropical fruits belonging to the genus Psidium and the Myrtaceae family and claim to have phenolic compounds that have been reported to possess strong antioxidant activity. This study was aimed to evaluate the bioactive constituents in guava cultivars at different ripening stages by HPLC. The five guava cultivars were selected at different ripening stages and the bioactive components were analysed by high-pressure liquid chromatography. The quantification of bioactive compounds revealed that the highest amount of bioactive compounds was found in cultivar Safeda at the unripe stage, while a minimum amount was found in ripe Apple Colour guava cultivar. The six bioactive compounds were quantified in the range of gallic acid (9.46-63.08 mg/100 g), quercetin (0.11-2.51 mg/100 g), myrcetin (0.09-0.034 mg/100 g), ascorbic acid (7.45-75.07 mg/100 g), apegenin (0.01-0.032 mg/100 g) and lycopene (0.34-0.92 mg/100 g). The exploratory eval...
Atlantis Press, 2024
Guava and green betle leaves have been reported to provide numerous medicinal benefits, including hepatoprotective, anti-inflammatory, antidiabetic, antioxidant, antipyretic, and analgesic effects. The aim of this study was to ascertain the total phenolic content and the antioxidant activity of a mixture of ethanol extracts from green betel and guava leaves. The total phenolic content was determined using the folin ciocalteu method, and antioxidant activity was tested using the DPPH method. A UV-Vis spectrophotometer was used to assess both procedures. An 1:0, 2:1, 1:1, 1:2, and 0:1 ratio was utilized in the combination of guava leaf and green betel leaf ethanol extracts. The standard of reference for the antioxidant activity test was ascorbic acid. In comparison to the comparison concentrations of 1:0, 0:1, 2:1, 1:1, and 1:2 generated very strong antioxidant activity potentials in scavenging free radicals. The determination of total phenolic levels significantly showed differences in the amount of levels at all comparative concentrations. Based on results, it is concluded that the combination of guava leaf and green betel leaf ethanol extracts at a 2:1 ratio has the potential for very strong antioxidant activity and high total phenolic content when compared to other concentrations.