A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical reacting with different levels of Trolox. This allowed the neural network to classify future images of any sample into the correct class of RSA level. The ANN was then able to determine the DPPH-RSA of cinnamon, clove, mung bean, red bean, red rice, brown rice, black rice and tea extract and the results were compared with data obtained using a spectrophotometer. The application of ANN correlated well to the spectrophotometric classical procedure and thus do not require the use of spectrophotometer, and it could be used to obtain semi-quantitative results of DPPH-RSA.
Kacip Fatimah (Labisia pumila Blume), one of the most famous and widely used herbs, especially in Southeast Asia, is found to have interesting bioactive compounds and displays health promoting properties. In this study, the antioxidant activities of the methanol extracts of leaves, stems and roots of three varieties of L. pumila (var. alata, pumila and lanceolata) were evaluated in an effort to compare and validate the medicinal potential of this indigenous Malaysian herb species. The antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, as well as the total amount of phenolics and flavonoids were the highest in the leaves, followed by the stems and roots in all the varieties. A similar trend was displayed by the ferric reducing antioxidant potential (FRAP) activity, suggesting that the L. pumila varieties possess high foliar antioxidant properties. At low FRAP activity concentrations, the values of the leaves' inhibition activity in the three varieties were significantly higher than those of the stems and roots, with var. alata exhibiting higher antioxidant activities and total contents of phenolics and flavonoids compared to the varieties pumila and lanceolata. The high production of secondary metabolites and antioxidant activities in var. alata were firmly related to low nitrogen content and high C/N ratio in plant parts. The study also demonstrated a positive correlation between secondary metabolite content and antioxidant activities, and revealed that the consumption of L. pumila could exert several beneficial effects by virtue of its antioxidant activity.
The present study was conducted to determine the effect of air (AD), oven (OD) and freeze drying (FD) on the free radical scavenging activity and total phenolic content (TPC) of Cosmos caudatus and the effect of storage time by the comparison with a fresh sample (FS). Among the three drying methods that were used, AD resulted in the highest free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50 = 0.0223 mg/mL) and total phenolic content (27.4 g GAE/100 g), whereas OD produced the lowest scavenging activity and TPC value. After three months of storage, the dried samples showed a high and consistent free radical scavenging activity when compared to stored fresh material. The drying methods could preserve the quality of C. caudatus during storage and the stability of its bioactive components can be maintained.
In this work, the bioactive compounds which was obtained by extracting Quercus infectoria via two extraction methods; Soxhlet and supercritical carbon dioxide (SC-CO2) extraction, were analyzed using total phenolic content and DPPH (2,2-diphenyl-1-picryl hydrazyl) free radical scavenging activity analysis. The aim of this study is to compare the total phenolic content and antioxidant activity of Quercus infectoria extract acquired from SC-CO2 extraction with those from Soxhlet extraction method. The results showed the used of SC-CO2 extraction give the lowest extraction yield as compared to Soxhlet extraction. The selectivity of Q. infectoria extracts using SC-CO2 extraction was better which in contrast with Soxhlet extraction method since it shows higher total phenolic content (143.75 ± 1.06 mg GAE/g sample). This study also revealed that the extracts from both extraction methods can posses’ antioxidant activity and comparable to those obtained from commercial antioxidant.
The aim of this study is to compare antioxidant level and activities (i.e. primary and secondary) in pulps and peels of two species of dragon fruits, Hylocereus undatus (white dragon fruit) and Hylocereus
polyrhizus (red dragon fruit). Total phenolic content (TPC) assay demonstrated that peels of both Hylocereus species contained higher phenolic content than the pulps. The phenolic content in peels of H. undatus was higher than H. polyrhizus, but the phenolic content in pulps of H. undatus was much lower than H. polyrhizus. 2, 2, diphenyl-1-picrylhydrazyl (DPPH) assay showed that radical scavenging activities of peels for both species were higher than the pulps. For ferrous ion chelating (FIC) assay, peels and pulps of both Hylocereus species showed moderate metal ion chelating effect as compared to EDTA. Overall, the results suggested that the TPC showed good relationship with the primary antioxidant activities for general comparison between the peels and the pulps.
Herbal tea is widely consumed around the world because people believed that it contained high amount of antioxidant. However, usage of different maturity of the plants as raw materials could affect the antioxidant capacities in herbal tea. Hence, this paper reports the antioxidant activity of herbal tea prepared from Cosmos caudatus at different maturity namely young, mature and old leaves. The analyses carried out were total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP) and DPPH (2-2-diphenyl- 1-picrylhydrazyl) radical scavenging assays. Based on the results obtained, herbal tea prepared from young leaves had significantly strong (p
This study aimed to optimise potential extraction conditions using response surface methodology (RSM) for yielding maximum levels of total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity of henna (Lawsonia inermis) stems. The ranges for selected independent variables, namely acetone concentration (20−90%, v/v), extraction time (10−90 min), and extraction temperature (25−45°C) were identified by screening tests. Optimum conditions obtained for extraction of TPC were 47.0% acetone, extraction time of 47.6 min and extraction temperature of 37.3oC. The result also showed that 75.8% acetone, extraction time of 26.2 min and extraction temperature of 41oC yielded the highest DPPH• scavenging capacity. The optimized extraction conditions have resulted in TPC and DPPH• scavenging capacity of 5232.4 mg GAE/100 g DW and 6085.7 mg TE/100 g DW, respectively which similar to the predicted values. Therefore, RSM has successfully optimized the extraction conditions for TPC and radical scavenging capacity of henna stems.
Medicinal properties of Malaysian Curcuma caesia have not been studied extensively, even though it has been used as a traditional remedy. This study examined the effects of various extraction temperatures (30, 40, 50, 60, 70oC) using a high frequency (40 kHz) ultrasonic extraction method, time (30,60,90 and 120 minutes), pH (1,2,3,4,5,6,7,8,9,10) on the extraction yield of total phenolics and DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activities from C. caesia rhizome. Extraction was most efficient at pH 6.0, while the extraction time of 30 minutes and temperature of 60oC was the best in terms of total phenolics content and DPPH scavenging activity. This study is important due to its ability to improve extraction of total phenolics compound using ultrasonic extraction method while maintaining a relatively high DPPH scavenging activity of the extracts.
2,4-Dimethylbenzoylhydrazones 1-30 were synthesized by condensation reactions of 2,4-dimethylbenzoylhydrazide with various aromatic aldehydes and characterized. The assigned structures of compounds 10, 15 and 22 were further supported by single-crystal X-ray diffraction data. The synthesized compounds were evaluated for their in vitro DPPH radical scavenging activity. They exerted varying degree of scavenging activity toward DPPH radical with IC₅₀ values between 25.6-190 µM. Compounds 1, 4, 2, 3, 7, and 6 have IC₅₀ values of 25.6, 28.1, 29.3, 29.8, 30.0 and 30.1 µM respectively, showing better activity than an n-propyl gallate standard (IC₅₀ value = 30.30 µM). For super oxide anion scavenging activity compounds 1, 2 and 3 with IC₅₀ values of 98.3, 102.6, and 105.6, respectively, also showed better activity than the n-propyl gallate standard (IC₅₀ value = 106.34 µM).
This study investigated the antioxidant activity and functional properties of fractionated cobia skin gelatin hydrolysate (CSGH) at different molecular weights (10, 5 and 3 kDa). Antioxidant activities studied included reducing power, ferrous ion chelation, DPPH (1, 1- diphenyl-2- picrylhydrazyl) radical scavenging, and superoxide anion scavenging. Functional properties studied included emulsifying and foaming properties as well as fat and water binding capacity. Results showed significant differences (p
The aim of this study was to determine the antioxidant activities of dietary bitter melon fruit supplemented in male rat model. In this study, three common tests for measuring antioxidant activity of the bitter melon were evaluated using 2, 2-diphenyl-l-picrylhydrazyl assay (DPPH assay), total phenolic acid assay (TPC assay) and Ferric reducing ability of plasma assa. (FRAP assay). Results showed that the extracting solvent significantly (P
Quercus infectoria gall, which is known as manjakani in Malaysia, was traditionally used in treating diseases. The bioactive compounds from the galls can be extracted using various extraction methods. In this study, supercritical carbon dioxide (SC-CO2) extraction was used to study the effects of CO2 flow rate on the yield, total phenolic content and antioxidant activity of Q. infectoria extract by fixing the pressure and temperature at the highest density (P: 30 MPa, T: 40°C). The results were compared with those acquired from the Soxhlet extraction method. The results showed that the Soxhlet extraction had a higher percentage of extraction yield than SC-CO2 extraction. The selectivity of Q. infectoria extracts using SC-CO2 extraction was better than the Soxhlet extraction method. Meanwhile, the extraction efficiency using the SC-CO2 extraction ranged from 46% to 53%. The SC-CO2 extraction also yielded higher total phenolic content than using the Soxhlet extraction method when 2 mL/min of CO2 flow rate was applied (203.53 mg GA/g sample). This study also revealed that the extracts from the SC-CO2 extraction showed a better radical scavenging activity compared to the Soxhlet extraction when analysed using DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activity assays.radical scavenging activity compared to the Soxhlet extraction when analysed using DPPH (2,2-diphenyl-1-picryl hydrazyl) radical scavenging activity assays.
Antioxidant capacities of ethylacetate, butanol, and water fractions of peel, pulp, and seeds of Canarium odontophyllum Miq. (CO) were determined using various in vitro antioxidant models. Ethylacetate fraction of peel (EAFPE) exhibited the highest total phenolic (TPC), total flavonoid content (TFC), and antioxidant activities compared to pulp, seeds, and other solvent fractions. Antioxidant capacities were assayed by total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical activity, ferric reducing antioxidant power (FRAP), and hemoglobin oxidation assay. Total phenolic content of ethylacetate fractions was positively correlated with the antioxidant activity. This is the first report on the antioxidant activities from CO fruit fractions. Thus, EAFPE can be used potentially as a readily accessible source of natural antioxidants and as a possible pharmaceutical supplement.
The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2',3',4',6'-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 microM. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2). 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.
Keupayaan Centella asiatica (CA) untuk bertindak sebagai antioksidan dan agen anti-radang telah banyak dilaporkan. Namun begitu, kaedah pengekstrakan CA untuk memperoleh hasil yang terbaik masih dipersoalkan. Dalam kajian ini, kami menilai tiga kaedah pengekstrakan CA dan membuat perbandingan ekstrak dari segi aktiviti antioksidan dan anti-radang, dan juga kandungan sebatian bioaktif, asiaticoside dan madecassoside. Centella asiatica diekstrak menggunakan pelarut etanol, metanol dan juga air. Kandungan sebatian fenolik ekstrak diukur menggunakan kaedah reagen Folin-Ciocalteu. Kandungan asiaticoside dan madecassoside ditentukan dengan kaedah HPLC. Aktiviti antioksidan diukur dengan asai 2,2-diphenyl-1-picrylhydrazyl (DPPH) dan asai penurunan kuasa Ferric Reducing Antioxidant Power (FRAP). Aktiviti anti-radang ditentukan dengan kebolehan ekstrak untuk merencatkan enzim tapakjalan keradangan, COX-1 dan COX-2, serta kebolehan ekstrak melindungi sel fibroblas aruhan 12-O-tetradecanoylphorbol-13-acetate (TPA) daripada menghasilkan prostaglandin E2 (PGE2 ). Hasil kajian menunjukkan aras sebatian fenolik, asiaticoside dan madecassoside tertinggi dalam ekstrak etanol, diikuti metanol dan esktrak akues (masing-masing 17.76 g/100g, 15.52 g/100g, 13.16 g/100g untuk sebatian fenolik, 42.86 mg/g, 36.37 mg/g, 2.82 mg/g untuk asiaticoside and 18.66 mg/g, 15.87 mg/g, 3.75 mg/g untuk madecassoside). Ketiga-tiga ekstrak menunjukkan aktiviti antioksidan sederhana berbanding kawalan positif. Kesemua ekstrak, asiaticoside dan madecassoside merencat COX-1 dan COX-2 dan menyekat penghasilan PGE2 -aruhan TPA. Ekstrak etanol dan metanol merupakan perencat COX yang lebih kuat dan lebih poten daripada ekstrak akues. Oleh itu, walaupun ekstrak akues menunjukkan kebolehan antioksidan yang lebih tinggi, dari segi aktiviti anti-radang, pelarut hidrofobik iaitu etanol dan metanol ternyata lebih baik untuk mengekstrak Centella asiatica.
The effects of squid ink at concentration of 0.10 and 0.25% on the total bacteria count and
chemical spoilage indicator; total volatile basis nitrogen (TVBN) and trimethylamine (TMA)
of squid (Loligo duvauceli) were analysed. The analysis were performed at interval of 5 days
during 15 days of chilled storage (4°C). This studies also investigate the antioxidant capacity
of the squid ink. The melanin-free squid ink were subjected to ferric reducing power (FRAP)
and 2,2-diphenyl-1-picrylhydrazyl (DPPH) analysis. The FRAP values found in squid ink were
0.04±0.01 µmole TE g-1 meanwhile DPPH values were recorded at 0.81±0.00 µmole TE g-1.
The squid ink at both 0.10 and 0.25% concentration showed a significantly (p
The extraction of phenolics from Citrus hystrix leaf was carried out using supercritical fluid extraction and was optimized using response surface methodology (RSM). The effects of CO2 flow rate, extraction pressure and extraction temperature on yield, total phenolic content and diphenyl-picrylhydrazyl-IC50 were evaluated and compared with ethanol extraction. The extraction pressure was the most significant factor affecting the yield, TPC and DPPH-IC50 of the extracts, followed by CO2 flow rate and the extraction temperature. The optimum conditions of pressure, CO2 flow rate and temperature were at 267 bars, 18 g/min and 50°C, respectively. The yield, TPC and DPPH-IC50 obtained were 5.06%, 116.53 mg GAE/g extract and IC50 of 0.063 mg/ml, respectively. These values were not significantly different (p
The effects of ethanol concentration (0-100%, v/v), extraction time (60-300 min) and extraction temperature (25-65°C) on the extraction of phenolic antioxidants from Andrographis paniculata was evaluated using single-factor experiments. The following complementary assays were used to screen the antioxidant properties of the crude extracts: total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity. The extraction conditions chosen had significant effects (p < 0.05) on the extraction of phenolic compounds and antioxidant capacity. The optimal conditions were 60% ethanol for 60 min at 65oC for phenolic compounds and at 25oC for antioxidant capacity. Strong negative significant (p < 0.05) correlations were observed between the phenolic compounds (TPC, TFC and CTC) and antioxidant capacity comprising ABTS (-0.924, -0.909, -0.887, respectively) and DPPH radical-scavenging capacities (-0.992, -0.938, -0.928, respectively) were determined under the influence of extraction temperature.
Garlic has been a favorite additive in food for many years in various cultures. It is known that garlic
(Allium sativum) possesses antimicrobial, antiprotozoal, antimutagenic, antiplatelet and antihyperlipidemic
properties. Allicin, a thiosulfinate extract of garlic, has been presumed to be a very strong antioxidant. High performance liquid chromatography (HPLC) analysis of raw garlic extract was not conclusive to determine allicin’s presence. However, using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging methods to determine the antioxidant activity of raw garlic extract shows a color change from deep violet to yellow, indicating antioxidant activity. Thus, raw garlic can be a source of antioxidant based on the results of the DPPH scavenging analysis.
Antioxidants in seaweeds have attracted increasing interest for its role in protecting human health. Therefore, the aim of this study was to assess the Total phenolic content (TPC) values and antioxidant activities in red seaweeds Kappaphycus alvarezii and Kappaphycus striatum of different solvent extracts. Total phenolic content (TPC) and antioxidant activities (DPPH scavenging assay and Trolox equivalent antioxidant capacity assay, TEAC) for both K. alvarezii and K. striatum extracts were determined using different solvents at different concentrations (ethanol: 50%, 70%, 100%; acetone: 50%, 70%, 100%; methanol: 50%, 70%, 100%). The TPC value was measured using the Folin-Ciocalteu’s method. The antioxidant activities were measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and Trolox Equivalent Antioxidant Capacity (TEAC) assay. The highest TPC value of K. alvarezii antioxidant extract was obtained by 50% ethanol extracts while for K. striatum obtained by 50% methanol extract. The highest percentage of DPPH free radical inhibition for K. alvarezii was shown by 50% acetone extract while K. striatum was shown using 50% methanol extract. The highest TEAC value for K. alvarezii was shown by 50% acetone while K. striatum extract was shown by 50% ethanol extract. The TPC values and antioxidant activities of all solvent extracts of K. striatum were significantly higher (p< 0.05) than K. alvarezii antioxidant extracts. The TPC values showed strong correlation (r = 0.797) with TEAC values for K. alvarezii antioxidant extract (p< 0.01). The TEAC values also showed strong correlation (r = 0.735) with percentage of DPPH free radical inhibition for K. alvarezii (p< 0.01). The TPC value, DPPH free radical scavenging assay and TEAC assay for K. striatum extracts showed strong correlation (r> 0.8) with each other (p< 0.01). In summary, K. striatum showed better antioxidant activity and higher TPC value than K. alvarezii.