Development dark chocolate enriched with mangrove leaf powder (Sonneratia alba): Physico-chemical properties, antioxidant activity, and sensory quality

BACKGROUND: Peronema canescens (Sungkai) leaves have been popular in Indonesia which contain various bioactive compounds with empirical therapeutic efficacy in dealing with COVID-19 and various other diseases. Total phenolic and flavonoid content and antioxidant activity using the DPPH method from P. canescens leaf extract have not been studied much. AIM: This research has several objectives. The first is to compare the results of qualitative phytochemical analysis of the ethanol extract of the leaves of P. canescens (EEPL). The second is to measure the total phenol and flavonoid content. The third is to test the FTIR and antioxidant activity of the ethanol extract of P. canescens leaves in vitro using the DPPH method. METHODS: Fresh plant material and simplicia, ethanol extract extracted by maceration method using 96% ethanol as solvent from P. canescens. The Dragendorff’s and Mayer test carried out the qualitative phytochemical analysis, FeCl3 test, Salkowski method, Liebermann–Burchard method, foam test, and NaOH reagent. The total phenolic and flavonoid levels were tested using the Folin–Ciocalteu method. In vitro antioxidant activity was carried out using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. RESULTS: The results of qualitative phytochemical screening showed that alkaloids, flavonoids, saponins, tannins, and steroids were detected in the extract of P. canescens. The spectra from the FTIR test results showed various absorbance peak values indicating the bonding of specific functional groups, namely: 418.12, 599.94, 666.67, 1036.39, 1159.52, 1224.16, 1348.95, 1454.19, 1600.87, 1732.00, 2923.13, and 3353.01 cm-1. In the test results, total phenolic content was as much as 5.64% (mgEAG/g) and total flavonoid content of 142,247 mgEQ/g in a sample of 1 mg extract, which was equivalent to 1 mg quercetin. EEPL has antioxidant activity with the DPPH IC50 method of 116.7865 ppm. CONCLUSION: The data obtained at this time can contribute to the exploitation of P. canescens leaves in the future as one of the nutraceutical products, supplements, and herbal medicines by specific industries related to improving the health status of the world community. The higher the bioactive substance in preparation, the more significant the effect of the pharmacological efficacy response. P. canescens ethanol extract has good total phenolic content, total flavonoid content, and antioxidant action.

The hawthorn Crataegus mexicana is a traditional Mexican fruit with properties that make this fruit useful for the treatment of many ailments, including diseases of the respiratory and urinary tract. This paper reports the antioxidant capacity of the n-hexane, dichloromethane, ethyl acetate, acetone, ethanol and methanol extracts of C. mexicana. Samples were evaluated for total phenolic and carotenoid contents, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, the inhibition of the formation of thiobarbituric acid reactive species (TBARS) and the neutralization of the cation-radical 2,2´-azino-bis(3ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS). The total phenolic content was 2.65 ± 0.23 mg of gallic acid equivalents per gram, and the carotenoid content was 26.4 ± 0.02 µg/g in dry hawthorn skin. The most active extract in scavenging DPPH radicals and inhibiting TBARS formation was the acetone extract, with activities of 21.9 ± 0.15 and 13.27 ± 0.70%, respectively, at 10 mg/L. The extracts were compared for activity against ascorbic acid, caffeic acid, α- tocopherol and quercetin. The acetone extract was the most active, with an IC50 value of 15.2 mg/L in DPPH and 17.7 mg/L in TBARS. A high correlation was observed between the results for TBARS and DPPH. These results demonstrate the potential nutritional and antioxidant value of this Mexican fruit.

Moringa stenopetala is a socioeconomic valued tree that is widely available and cultivated in Southern part of Ethiopia. The leaves have been traditionally used as a food source with high nutritional and medicinal values. The present work was carried out to evaluate the effect of thermal treatment on the total phenolic content, total flavonoid content, antioxidant activities and α-amylase inhibition of aqueous leaf extracts obtained from M. stenopetala during maceration and different decoction time interval (5, 10 and 15 min). The total phenolic and flavonoid contents were determined by the Folin-ciocalteu and aluminum chloride methods, respectively whereas antioxidant activities were determined by 2,2-diphenyl-1-picryl-hydrazyl(DPPH) radical scavenging, reducing power, phosphomolybdenum and ferrous ion chelating assays and α-amylase inhibition potential was determined using 3,5-dinitrosalicylic acid method. Total phenolic and total flavonoid contents ranged from 34.35 ± 1.06 to 39.47 ± 1.33 mgGAE/g and 10.44 ± 0.61 to 20.36 ± 0.93 mgQRE/g, respectively. Decoction for 10 min extract showed ferrous ion chelating (92.52 ± 0.17 %), DPPH radical scavenging (91.52± 0.59 %), α-amylase inhibition (69.06 ± 0.14%), ferric reducing power (0.765 ± 0.14) and total antioxidant activity (0.329 ± 0.32), respectively. DPPH, reducing power, total antioxidant and α-amylase inhibition activities showed positive linear correlation (R2=0.853, R2= 0.857 , R2= 0.864 and R2=0.930), respectively with total phenolic content but ferrous ion chelating activity were found to be weakly correlated (R2=0.481). Based on present investigation, it could be concluded that major lose of total phenolic content, antioxidant and α-amylase inhibition activities of the crude leaf extracts of M. stenopetala leaves were observed at decoction time for 15 min. Therefore, to maintain the total phenolic content, antioxidant and α-amylase inhibition activities of leaves, cooking practice should be at the optimum decoction time (5-10 min). Key words: Moringa stenopetala, antioxidant, total phenolic content, α-amylase inhibition.

Objectives: The goals of this research were to evaluate antioxidant potential from different organs of eggplant (Solanum melongena L.) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and correlation of total phenolic and flavonoid content with their inhibitory concentration 50% (IC50) of DPPH, and exhibitory concentration 50% (EC50) of FRAP.Materials and Methods: Each sample was extracted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Antioxidant activities were tested using DPPH and FRAP assays, determination of total phenolic and flavonoid content were carried out by ultraviolet-visible spectrophotometry and correlation with their IC50 of DPPH and EC50 of FRAP capacities were analyzed by Pearson’s method.Results: The lowest IC50 of DPPH scavenging activity 1.14 μg/ml and the lowest EC50 of FRAP capacity 49.80 μg/ml was given by ethanolic leaves extract of eggplant. Ethanolic leaves extract of eggplant also presented the highest total phenolic content (TPC) (8.87 g gallic acid equivalent/100 g), while the highest total flavonoid content was shown by ethyl acetate leaves extract (24.50 g quercetin equivalent/100 g). There was a significantly negative correlation between TPC in leaves and fruit extracts of eggplant with their IC50 of DPPH and EC50 of FRAP.Conclusions: All different extracts of eggplant organs (except n-hexane stem extract) were categorized as a very strong antioxidant by DPPH method. Phenolic compounds in eggplant leaves and fruit extracts were the major contributor in antioxidant activities by DPPH and FRAP methods. DPPH and FRAP showed linear results in antioxidant activities of eggplant leaves, fruit and stem extracts.

Abstract. Nurhasnawati H, Sundu R, Sapri, Supriningrum R, Kuspradini H, Arung ET. 2019. Antioxidant activity, total phenolic and flavonoid content of several indigenous species of ferns in East Kalimantan, Indonesia. Biodiversitas 20: 576-580. This study aimed to determine the total phenolic and flavonoids content and antioxidant activity of ethanol extract of several indigenous species of ferns in East Kalimantan. Total phenolic content was determined by Folin-Ciocalteau method and flavonoid content was measured by colorimetric method. Antioxidant activity was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The result of photochemical screening indicated that the leaves of Plagiogyria pycnophylla, Plagiogyria glauca, and Stenochlaena palustris contained alkaloid, flavonoid, tannin, saponin, and steroid while Acrostichum aureum contained flavonoid, tannin, saponin and steroid. The result showed extract Acrostichum aureum had the highest total phenolic content (366.4573 ± 2.2117 mg GAE.g-1), flavonoid content (228.6087 ± 2.2548 mg QE.g-1), and very strong antioxidant activity with IC50 value 29.5303 ppm. There is positive correlation between total phenolic content, flavonoid with antioxidant activity.

Objective: To determine antioxidant activity and phytochemical content from various tubers extracts of sweet potato (Ipomoea batatas) and to explore the correlation of phytochemical content with their antioxidant activities. Methods: Antioxidant activities were tested using DPPH and FRAP assays. Total phenolic was calculated by Folin-Ciocalteu reagent, flavonoid content by Chang’s method and correlation with their antioxidant activities were analyzed by Pearson’s method. Results: PO2 showed highest antioxidant activity, which had the lowest IC50 DPPH (10.54 μg/mL) and the lowest EC50 FRAP (11.14 μg/mL). PO2 showed the highest total phenolic (11.91 g GAE/100 g) and total flavonoid content (17.83 g QE/100 g). There were significantly negative correlation between total phenolic content and flavonoid content in sample PO with their IC50 DPPH and EC50 FRAP. IC50 DPPH of sample PP and PO showed significantly positive correlation with their EC50 FRAP. Conclusions: Result of DPPH method shows that all different ethyl acetate and ethanolic tubers extracts of four varieties of sweet potato are classified as strong and very strong antioxidant. Result of DPPH and FRAP methods indicates that phenolic and flavonoid compounds in sample PO contributes together to antioxidant activities. Antioxidant activities of sample PP and PO by DPPH method are linear to FRAP method.

Biological activities and phytochemical content of the rhizome hairs of Cibotium barometz (Cibotiaceae)

Objectives: The goals of this research were to observe antioxidant properties from different parts of Simana lagi apple ([Malus domestica Borkh.] “Simana lagi”) using two antioxidant testing methods which were 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzthiazoline-6- sulfonic acid (ABTS) and correlation of total phenolic and flavonoid content with their inhibitory concentration 50 (IC50) of DPPH and IC50 of ABTS.Methods: Each sample was extracted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Antioxidant activities were tested using DPPH and ABTS assays, determination of total phenolic, and flavonoid content were carried out by ultraviolet-visible spectrophotometry and correlation with their IC50 of DPPH and IC50 of ABTS activities were analyzed by Pearson’s method.Results: The ethanolic leaves extract (LV3) of Simana lagi apple also exposed the highest total phenolic content (TPC) (13.88 g gallic acid equivalents/100 g), while the highest total flavonoid content was presented by ethyl acetate extract (LV2) (7.21 g QE/100 g). The lowest IC50 of DPPH scavenging activity 0.19 μg/ml, and the lowest IC50 of ABTS scavenging activity 0.15 μg/ml was given by ethanolic flesh extract (FL3) of Simana lagi apple. There were significantly negative correlation between TPC in all different parts extracts of Simana lagi apple with their IC50 of DPPH and IC50 of ABTS.Conclusions: All different parts extracts of Simana lagi apple were categorized as very strong antioxidant by DPPH and ABTS method (except n-hexane peels extract and n-hexane LV by DPPH method, and n-hexane FE by ABTS method). The major contributor in antioxidant activities of peels, flesh and leaves extracts of Simana lagi apple by DPPH and ABTS methods were phenolic compounds. Antioxidant activities of peels, flesh and leaves extracts of Simana lagi apple showed linear results by DPPH and ABTS methods.

Series of experiments were conducted to screen phytochemical constituents, antioxidant and analgesic activities of the ethanolic extracts of the plant Croton argyratus. The extracts obtained from leaves, stem and root of the plant were evaluated for their antioxidant activity by means of 2,2- Diphenyl -1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and total antioxidant capacity as well as total phenolic and flavonoid contents was studied. To determine analgesic property of the antioxidant rich extract, and formalin induced pain, hot plate and tail flick test were performed. The leaves extract showed the highest value of antioxidant activity based on DPPH radical scavenging activity, reducing power and total antioxidant capacity. The leaf extract also produced the highest total phenolic and total flavonoid content and have a significant activity in late phase of the formalin induced pain test at the dose of 200 mg/kg p.o. However, in the hot plate and tail flick tests, the extract did not show any significant analgesic effects. The results suggested the potential use of C. argyratus plant extracts as a natural source of antioxidant and may act peripherally to relieve pain. Key words: DPPH, reducing power, total antioxidant capacity, total phenolic content, total flavonoid content, peripheral analgesic.

Summary Introductıon: Instead of synthetic antioxidants, using of natural products with antioxidant activity is demanded. Objectıve: The aim of this study is to evaluate the antioxidant activity and total phenolic and flavonoid contents of the Trachystemon orientalis (borage) obtained from Ordu. Methods: The water and ethanol extracts of the borage plant were investigated by using several in vitro antioxidant activity tests such as total antioxidant capacity, O2 •−, •OH, DPPH and ABTS radicals scavenging activities, hydrogen peroxide scavenging activity, FRAP, Fe2+ chelating and reducing power assays in order to make effective comparisons. Results: Water extract of the T. orientalis had the more phenolic (90 mg GA/g extract) and flavonoid (56.88 mg CT/g extract) contents than ethanol extract. Furthermore, both of the extracts showed strong antioxidant and radical scavenging activities determined by different in vitro models. The highest total antioxidant capacity as ascorbic acid equivalents of 244.50 mg/g extract was also calculated for water extract. Generally, a relationship between total phenolic content and antioxidant activity was established. It is also an important finding for an edible food source that the phenolic and flavonoid content and antioxidative activities for water extract was higher than the ethanol extract. Conclusıon: T. orientalis could be used as a food ingredient instead of synthetic antioxidants and all results will contribute to the recent increase in investigations on using natural products in many areas such as food, pharmacy, alternative medicine and natural therapy.

This study aims to determine and compare antioxidant activity, total phenolics, flavonoids, and the relationship of phenolic and total flavonoids with the antioxidant activity of the three kratom variants. The ethanol extract of the third variant of kratom leaves was obtained by maceration. Through the antioxidant activity test using DPPH method, all three extracts showed strong antioxidant activity with IC50 values of 26.39, 30.25, and 30.59 μg/mL. The relationship of total phenolics and flavonoids with antioxidant activity was determined by the Pearson correlation test. Examination of total phenolic content using the Folin-Ciocalteu method with successive results for green, red, and white kratom are 6.11, 8.67, and 9.09 mg GAE/g extract. Examination of total flavonoid content using the colorimetric method for green, red, and white kratom were 0.86, 0.68, and 1.13 mg QE/g extract, respectively. The total phenolic content and antioxidant activity showed a correlation coefficient value of -0.32 (P0.05), and the total flavonoid content to antioxidant activity showed a correlation coefficient value of 0.81 (P0.05). Thus, all three variants of kratom have potency as natural antioxidants, but their total phenolic and flavonoid content does not influence their antioxidant activity.

Introduction: Tigarun (Crateva magna DC.) is a medicinal plant traditionally used in South Kalimantan to treat various ailments. Its leaves contain bioactive compounds such as phenolics and flavonoids with known antioxidant properties. However, scientific data on the antioxidant capacity and quantitative composition of these compounds, particularly from local populations, remain limited. This study therefore evaluates the antioxidant activity and quantifies the phenolic and flavonoid contents of Tigarun leaf extracts to support its traditional use scientifically. Aims: This study aimed to determine the total phenolic and flavonoid content and evaluate the antioxidant activity of tigarun leaf extract. Methods: The dried tigarun leaves were extracted by maceration using 70% ethanol. Total phenolic content was analyzed using the Folin–Ciocalteu method with gallic acid as the standard, while total flavonoid content was determined by the aluminum chloride method using quercetin. Antioxidant activity was evaluated using the DPPH method and expressed as Ascorbic Acid Equivalent Antioxidant Capacity (AEAC). Results: The total phenolic content of the extract was 5.741 g GAE/100 g extract, and the total flavonoid content was 2.685 g QE/100 g extract. The antioxidant activity was 209.772 ± 2.432 mg AEAC/g extract, indicating strong free radical scavenging ability. Conclusion: The ethanolic extract of Tigarun (Crateva magna DC.) leaves showed notable phenolic and flavonoid contents with strong antioxidant activity. Compared with related species such as Crateva nurvala, these levels are within a comparable range, supporting the potential of Tigarun as a natural antioxidant source for pharmaceutical or nutraceutical applications.

The sweet chestnut fruit has always had great importance in the southern European countries. Chestnut production is an important source of income and a crop of high environmental value thanks to its role in soil protection. It is also a good food with enormous potential for various aspects of health because of its nutritional qualities. The quality of sweet chestnuts is affected by various factors, such as climatic conditions and cultivation inputs. It is very important to recognize the impacts of climate on chestnut fruits, to improve our current understanding of climate–chestnut interconnections. The current study investigated and compared the antioxidant activity and the total phenolic and flavonoid contents of different cultivars of chestnuts grown in different geographic areas of northwest Spain. The results obtained with three antioxidant capability assays (DPPH, ABTS and FRAP assays) were highly correlated. All the samples had high antioxidant capacity and high total phenolic and total flavonoid contents, which depended both on cultivar and growth region. Ventura variety, harvested in the coldest environments, presented the highest values of antioxidant activity (IC50DPPH = 34.5 g/L), total phenolic content (131.84 mg equivalent of gallic acid/100 g FW) and total flavonoids (7.77 mg eq. catechin/100 g). The variations in the antioxidant capacity, total phenolic and total flavonoid contents of different cultivars, and their associations with climatic environmental factors, revealed the significant impacts of these factors on the synthesis of specialized metabolites and on the nutraceutical potential of chestnuts. The results can provide valuable information for selection of the cultivar and the cultivation conditions of the chestnut, in order to obtain chestnuts with high-quality bioactive characteristics.

Antioxidant activity (AOA) in fruits of Sambucus nigra and several new elderberry interspecific hybrids involving S. javanica (JA), S. nigra subsp. nigra (NI), S. nigra subsp. nigra ‘Black Beauty’ (BB), S. nigra subsp. cerulea (CER) and S. racemosa (S. racemosa subsp. racemosa (RAC), S. racemosa subsp. racemosa var. miquelii (MIQ), S. racemosa subsp. tigranii (TIG), S. racemosa subsp. kamtschatica—coreana (KOR) at five maturity stages were investigated by applying DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric reducing antioxidant power) and ORAC (oxygen radical absorption capacity) assays. The aim of the study was to compare different assays for estimating AOA in elderberries, to plan the appropriate harvest time and to determine whether the most promising genotypes could be predicted in advance. All assays used showed that AOA increased significantly during maturation. All assays were significantly correlated with each other and could be reliably used for the AOA determination of elderberries. In fully mature berries, significant correlations were also found between total phenolic (TP) content and AOA by all assays, but no significant correlations were found between total ascorbic acid (TAA) content and AOA by all assays. At the fully mature stage, (the most appropriate stage for harvesting), berries of (JA × NI) × BB and (JA × NI) × MIQ were found to be superior in AOA and TP content. Genotypes with higher/lower AOA and TP content could not be predicted in advance, while TAA showed the opposite.

Antioxidant capacity (AC) was determined by the ABTS method and DPPH, and total phenol content (TPC) in dehydrated plant material, in infusions and in residues (plant material after preparing the infusion) of white, black, red, green, spearmint, stevia, lemon grass and chamomile teas to which stevia leaves were added or not added; addition of processed stevia powder was also tested. Three independent experiments were set up: with dehydrated plant material, with infusions and with residues. For the case of dehydrated plant material, white tea had the highest TPC (10813.5 mg GAE/100g) and AC by the ABTS method (1183.3 µM TE/g) and DPPH method (1525.0 µM TE/g). In infusions, black tea had higher TPC (180.82 µg GAE/ml) and AC by the methods ABTS and DPPH (0.6114 and 2.5983 µM TE/ml, respectively). In residues, TPC was higher in white tea, while green tea had the highest AC values. AC of dehydrated plant material increased when stevia leaves were added, according to the DPPH and ABTS methods, but not in residues by ABTS. Addition of stevia leaves in infusions increased AC in white, lemon grass, chamomile and stevia teas by the ABTS method and in spearmint, black, red, and green teas with the DPPH method.