ASCORBIC ACID, TOTAL PHENOLICS AND ANTIOXIDANT ACTIVITY OF GUAVA LEAF EXTRACTS

2014 ◽  
pp. 367-372 ◽  
Author(s):  
K. Iamjud ◽  
N. Banyen ◽  
U. Boonprakob ◽  
K. Thaipong
Author(s):  
Sharmistha Banerjee ◽  
Shuchi Kaushik ◽  
Rajesh Singh Tomar

ABSTRACTObjective: This study was performed to identify the phytochemicals and comparatively evaluate the antioxidant activity of Calotropis procera andAzadirachta indica by detection of total phenolics, hydrogen peroxide radical scavenging activity, and estimation of condensed tannins in differentsolvent systems and at different temperatures.Methods: Leaves of C. procera and A. indica were extracted in water, methanol by soaking dried leaf powder at room temperature and also by boilingthe leaf powder in water for 30 minutes. Phytochemical tests were performed in all of the extracts. The antioxidant activity was determined byhydrogen peroxide radical scavenging activity. Quantitative estimation of total phenolics and hydrolysable tannins was also performed.Results: The total phenolics in both leaf extracts was obtained maximum in boiled extract (40.7±1.20 mg gallic acid equivalent [GAE]/g dry extractin C. procera and 33.66±1.45 mg GAE/g dry extract in A. indica). The amount of hydrolysable tannins in both leaf extracts was found to be highest inmethanol (150±1.88 mg catechin equivalent/g dry extract in C. procera and 144.8±2.63 mg catechin equivalent/g dry extract in A. indica).Conclusion: The study showed promising results indicating that these plants are a good source of antioxidants. The majority of phytochemicals wereextracted in distilled water and methanol acts as a good solvent for extraction of tannins, whereas an increase in temperature leads to poor extractionof tannins.Keywords: Antioxidant, Phytochemicals, Phenolics, Radical, Tannins.© 2017 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (http://creativecommons.


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.


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 607
Author(s):  
Susanna Buratti ◽  
Carola Cappa ◽  
Simona Benedetti ◽  
Gabriella Giovanelli

This study investigates the effects of three cooking methods (boiling, steaming and microwaving) on the nutritional and physical properties of cauliflowers, carrots and sweet potatoes; e-senses were applied to interpret the sensory characteristics according to physico-chemical aspects. The nutritional quality was evaluated by determining the concentrations of key components and the antioxidant activity; e-sense data, combined with texture parameters, were processed by a principal component analysis. The cooking method and time significantly influenced the quality of the three products. Boiling, which detrimentally affected ascorbic acid, total phenolic concentration and antioxidant activity, enhanced carotene accessibility. Steaming produced losses in ascorbic acid, increasing total phenolics and carotenoids. Microwaving resulted in minor changes in ascorbic acid concentrations, preserved carotenoids and increased total phenolics. The nutritional quality was better preserved or enhanced using shorter cooking times. The elaboration of the data collected by the e-senses showed a clear evolution according to the cooking method and time. The results helped to determine the cooking method that best preserves the nutritional properties of the vegetables, highlighting the applicability of rapid instrumental methods to interpret the evolution of sensory characteristics.


Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 298 ◽  
Author(s):  
Aldo Tava ◽  
Łukasz Pecio ◽  
Roberto Lo Scalzo ◽  
Anna Stochmal ◽  
Luciano Pecetti

Phenolics are important mediators in plant-environment interactions. The presence and concentration of phenolic compounds and their antioxidant activity were evaluated in leaves and flowers of a set of Trifolium species originating from contrasting environments encompassing lowland and mountain sites. The current germplasm proved a great reservoir of phenolic compounds, with different chemical structure and, possibly, diversified biological activity. Germplasm groups with specific phenolic composition were observed. In some cases, different patterns bore a taxonomic meaning. Lowland germplasm showed higher concentration of total phenolics in leaves than mountain accessions (50.30 vs. 34.19 mg/g dry matter (DM)), while the latter had higher concentration in flowers (114.16 vs. 57.44 mg/g DM). Outstanding concentration of isoflavones was observed in leaves of lowland germplasm (24.19 mg/g DM), and of both proanthocyanidins and flavonoids in flowers of mountain germplasm (53.81 and 56.62 mg/g DM, respectively). The pattern of phenolic composition in lowland and mountain germplasm was suggestive of different adaptive strategies. Three assays of antioxidant activity were tested, which were characterised by rather different reactivity towards phenolic composition. The scavenging activity was higher for leaf extracts of lowland germplasm, and for flower extracts of mountain germplasm. Besides identifying germplasm of interest, this study also suggested possible links between environmental factors and concentration and composition of phenolic compounds.


Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 926
Author(s):  
Victoria Chepel ◽  
Valery Lisun ◽  
Liubov Skrypnik

Heather (Calluna vulgaris (L.) Hull.) is noted for a diverse chemical composition and a broad range of biological activity. The current study was aimed at monitoring changes in the accumulation of certain groups of phenolic compounds in various organs of heather (leaves, stems, roots, rhizomes, flowers, and seeds) at different growth stages (vegetative, floral budding, flowering, and seed ripening) as well as studying antioxidant (employing the DPPH and FRAP assays) and antibacterial activity of its extracts. The highest total amount of phenolic compounds, tannins, flavonoids, hydroxycinnamic acids, and proanthocyanidins was detected in leaves and roots at all growth stages, except for the flowering stage. At the flowering stage, the highest content of some groups of phenolic compounds (flavonoids, proanthocyanidins, and anthocyanins) was observed in flowers. Highest antioxidant activity was recorded for the flower extracts (about 500 mg of ascorbic acid equivalents per gram according to the DPPH assay) and for the leaf extract at the ripening stage (about 350 mg of ascorbic acid equivalents per gram according to the FRAP assay). Strong correlation was noted between antioxidant activity (DPPH) and the content of anthocyanins (r = 0.75, p ≤ 0.01) as well as between antioxidant activity (FRAP) and the total content of phenolic compounds (r = 0.77, p ≤ 0.01). Leaf extracts and stem extracts turned out to perform antibacterial action against both gram-negative and gram-positive bacteria, whereas root extracts appeared to be active only against B. subtilis, and rhizome extracts against E. coli.


2016 ◽  
Vol 36 (03) ◽  
pp. 270 ◽  
Author(s):  
Ermi Sukasih ◽  
Setyadjit Setyadjit

Recently, there is an increase of shallot production in Indonesia. One alternative of flesh shallot processing is shallot powder making which can be used during the off season. The aim of the study was to observe the effect of immersion in ascorbic acid and sodium bisulphite on two varieties of shallot on physical and organoleptic characters of shallot powder. Drying was done using tray dryer. Experimental design used was factorial completely randomised design. The first factor was the type of immersion agent and duration time and the second factor was shallot varieties (Bima and Sembrani). Statistical mean test was using Tukey Honestly Significant (HSD). The result showed that the treatments significantly affected parameters such as moisture content, ascorbic acid, total phenol, anthocyanin, and antioxidant activity, free radical inhibition and color (chroma). From ranking test the best treatment was Bima variety with 0.2% ascorbic acid treatment for 30 min. Characteristic of the best treatment was with moisture content 4.03±0.79 % (w/w), ash content 4.45±0.13 % (w/w), fat content 1.24±0.64 % (w/w), protein content 15.56±0.28 % (w/w), 61.94±4.11 mg/100g, total phenolics 256.39±16.26 ppm, anthocyanins 50.70±2.31 ppm, quercetin 2612.40±408.94 ppm, antioxidant activity ekuivalent, 225.72±4.0 µg/mL, inhibition free radical 83.05±1.69 %, 85.02 hue value (yellowish red) and aroma score 3.2 (strong), brightness score 4.2 (bright) and color 1.25 (pale red). ABSTRAKKenaikan cukup signifikan pada produksi bawang merah terjadi di Indonesia. Salah satu alternatif pengolahan bawang merah segar adalah melalui pengolahan menjadi tepung sehingga tetap tersedia saat langka dan harganya tinggi. Penelitian ini bertujuan untuk melihat pengaruh perendaman asam askorbat dan natrium bisulfit pada dua varietas bawang merah terhadap sifat fisikokimia dan organoleptik tepung yang dihasilkan. Pengeringan dilakukan dengan tray dryer. Percobaan menggunakan rancangan acak lengkap faktorial, faktor pertama jenis bahan  dan lama perendaman dan faktor kedua adalah varietas bawang merah (Bima dan Sembrani). Analisis statistik menggunakan metode Tukey Honestly Significant Data (HSD). Hasil penelitian menunjukkan bahwa perlakuan berpengaruh nyata terhadap parameter kadar air, vitamin C, total fenolik, antosianin, aktivitas antioksidan, inhibisi radikal bebas dan warna (chroma). Berdasarkan uji peringkat diperoleh perlakuan terbaik adalah tepung bawang merah dari varietas Bima dengan perlakuan perendaman asam askorbat 0,2 % selama 30 menit. Karakteristik dari tepung bawang ini memiliki  kadar air 4,03 ± 0,79 % (bb), kadar abu 4,45 ± 0,13 % (bb), lemak 1,24 ± 0,64 % (bb) protein 15,56 ± 0,28 % (bb), vitamin C 61,94 ± 4,11 mg/100 g, total fenol 256,39 ± 16,26 ppm, antosianin 50,70 ± 2,31 ppm, kuersetin 2612,40 ± 408,94 ppm, aktivitas antioksidan ekuivalen 225,72 ± 4,07 µg/mL, inhibisi radikal bebas 83,05 ± 1,69 %, nilai oHue 85,02 (kuning kemerahan) dan skor aroma 3,2 (kuat), skor kecerahan 4,2 (terang) dan skor warna 1,25 (merah pucat).   Kata kunci: Asam askorbat; tepung bawang merah; perendaman; natrium bisulfit


Author(s):  
HEMALATHA M ◽  
BHAKSHU L ◽  
YASODAMMA N

Objective: The leaf extracts of Cassia montana (Caesalpiniaceae) were being used for leucorrhea and rheumatic pains used by the certain tribal people in Andhra Pradesh. The present studies focused on the antibacterial, antioxidant activity of leaf extracts of C. montana which provide the scientific basis for its folklore applications in various ailments. Methods: Ethyl-alcohol and water extracts of C. montana (leaf) were screened for phytochemicals, antimicrobial activity and antioxidant activity using in vitro methods. The total phenolics were estimated using Folin–Ciocalteu reagent with reference to gallic acid, whereas the antioxidants of the extracts were quantified using ammonium molybdate reduction assay with reference to the ascorbic acid. The antibacterial activity was studied by disk-diffusion method and the radical scavenging assay by DPPH discoloration method with reference to ascorbic acid. Results: The leaf extracts were tested for antibacterial, antioxidants, and phytochemical screening and found the significant phytoconstituents as steroids, lignins, flavonoids, phenols, glycosides, tannins, cardiac glycosides, and reducing sugars in ethanol and aqueous extracts. The tested extracts exhibited significant antibacterial activity. It is also observed that ethanolic extracts are more effective with minimum inhibition concentrations values at 28 and 32 μg/disk against Bacillus subtilis and Staphylococcus aureus followed by Klebsiella pneumonia and Pseudomonas aeruginosa with 80 and 90 μg/disk. Total polyphenols quantified in alcohol and water extracts with reference to the gallic acid is 108 and 267 mg/g dry weight of leaf, respectively. Total antioxidants quantified in alcohol and water extracts with reference to the ascorbic acid is 70 and 85 mg/g dry weight of leaf, respectively. The tested extracts were exhibited strong effect on the discoloration of DPPH indicated the significant scavenging activity. Conclusion: The present study revealed that the tested extracts were exhibited significant anti-bacterial antioxidant activity along with the diversified phytochemicals. Hence, the leaf extracts of C. montana were having potential role in the treatment of ethno botanical health claims.


2004 ◽  
Vol 2 (3) ◽  
pp. 153-166 ◽  
Author(s):  
Peter M. Hanson ◽  
Ray-yu Yang ◽  
Susan Lin ◽  
Samson C. S. Tsou ◽  
Tung-Ching Lee ◽  
...  

Pepper (Capsicum sp.) is important in human diets in many parts of the world and a major source of several antioxidants, including carotenoids, ascorbic acid, tocopherols and phenolics. More information on genetic diversity within Capsicum for antioxidant (AO) content and antioxidant activity (AOA) could contribute to improved human health. We evaluated 46 Capsicum accessions from AVRDC—the World Vegetable Center Capsicum core collection for content of nine AO (five carotenoids, ascorbic acid, tocopherols α and γ, and total phenolics) and two AOA assays for 2 years in south Taiwan. Ample genetic diversity exists within C. annuum to increase AO content. Based on dry weight values, non-pungent C. annuum entries as a group were significantly greater than pungent entries for contents of β-cryptoxanthin (36%), ascorbic acid (65%), total phenolics (36%) and α-tocopherol (11%). Group means of the brown-fruited entries exceeded the means of red-fruited entries for capsanthin (34%), zeaxanthin (37%), lutein (36%), β-cryptoxanthin (71%), β-carotene (82%), ascorbic acid (19%) and α-tocopherol (40%). Red-fruited C. annuum entries ‘Verdano Poblano’ and ‘Guajillo Ancho’ from Mexico ranked among the entries highest for all carotenoids, ascorbic acid and α-tocopherol. The inhibition of lipid peroxidation (ILP) assay could be adopted for AOA characterization or selection because of high variation among entries and consistent entry performance over years. ILP was positively correlated with phenolics (r=0.72**) and ascorbic acid (r=0.58**) contents. Significant positive correlations were detected between most carotenoids as well as a significant positive correlation between ascorbic acid and total phenolics contents (r=0.78**).


2013 ◽  
Vol 5 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Gholamhossein DAVARYNEJAD ◽  
Mehdi ZAREI ◽  
Elham ARDAKANI ◽  
Mohamad Ebrahim NASRABADI

The limited postharvest storage life of apricot is the focus of this study. Presenting a solution to improve the postharvest storage of studied apricot cultivars is the goal. Studding the effect of different concentration of postharvest putrescine on quality attributes and antioxidant activity of two apricot cultivars during storage is the approach taken. The two apricot cultivars (‘Lasgerdi’ and ‘Shahrodi’) were harvested at the commercial ripening stage, and fruits were immerged in 1, 2, 3 and 4 mM putrescine as well as distilled water (control) for 5 min, then fruits were packed in boxes with polyethylene cover and stored at 4°C and 95% relative humidity for 20 days. The changes in weight loss, fruit firmness, total soluble solids, titratable acidity, pH, maturity index, ascorbic acid, total phenolics and antioxidant activity were estimated after 0, 5, 10, 15 and 20 days during storage. The results showed that the weight loss, total soluble solids, pH and maturity index increased significantly while the fruit firmness, titratable acidity, ascorbic acid, total phenolics and antioxidant activity decreased significantly during storage for both cultivars. During storage, a significant difference between control and putrescine treatments in all measured parameters is observed. The putrescine treatments reduced significantly the weight loss and maintained their firmness. In this condition, the highest and lowest of titratable acidity, ascorbic acid, total phenolics and antioxidant activity were observed in treatments of 4 mM putrescine and control, respectively. The data revealed that the quality of apricot fruits was improved by the use of putrescine treatment due to its effect on delaying the ripening processes.


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