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This study aims to find out how pomposia fruit powder (Syzygium cumini L.) mixed with roasted coffee (RCO) affected antioxidants, phytochemicals, lipid peroxidation inhibition and sensory attributes.

Pomposia fruits (Syzygium cumini L.) powder (PFP) was integrated with RCO at levels of 0.0%, 5.0%, 10.0%, 15.0% and 20.0%. RCO, PFP and binary mixtures containing RCO: PFP were evaluated for their total phenolics (TP), total flavonoids (TF), anthocyanin content (AC), antioxidant activity and phenolic compounds fractionation. The oxidative indices of coffee oil samples were measured throughout different storage intervals. Additionally, sensory characteristics of RCO enriched with different PFP doses were evaluated.

PFP samples exhibited the greatest TP content (1910 mg/100 g), whereas RCO samples had the lowest concentration (1090 mg/100 g). As more PFP was added, the corresponding coffee blends’ concentrations of TP, TF and AC were improved significantly. PFP possesses a radical-scavenging activity that is about 1.20 times more than RCO’s. DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity jumped significantly from 74.13% in control (untreated) samples to 77.64%, 78.39% and 80.15% for samples enriched with 10.0%, 15.0% and 20% PFP, respectively. Significant increases in gallic acid, hesperidine, benzoic acid, chlorogenic acid, hispertin, catechol, quercetin, pyrogallol and rutin were detected when RCO was mixed with different quantities of PFP. At the end of storage trial, the coffee oil treated with 20% PFP had AV, PV and TBA values that were about 1.70, 1.95 and 1.66 times lower, respectively, than those of the control sample that had not had PFP addition. The RCO with 5.0% PFP achieved the greatest over acceptability grades.

To the best of the authors’ knowledge, this study was the first study to evaluate the effect of incorporating various level of pomposia fruit powder into RCO. The findings shows that adding different concentrations of pomposia fruit powder into RCO can indeed enhance the radical-scavenging activity of the coffee and potentially extend its shelf life.

This paper seeks to investigate Cordia myxa L. (CM) extracts as hepatoprotective agents, through their antioxidant activities.

Oxydative liver damage in rats was induced in Wister rats by two agents: carbon Tetrachloride (CCl₄) and thioacetamide (TA). Oxydative damage was evaluated by a measurement of aspartate transaminase (AST), glutamate transaminase (ALT) and Alkaline phosphatase (ALP), in sera of the rats. Several extracts of Cordia myxa were prepared and were fed to experimental animals over a period of two weeks. Liver recovery was assessed by measuring the above hepatic enzymes and their comparison with the control group of animals. Phenolic content of the extracts was measured by Folin‐Ciocalteu reagent and was calculated as gallic acid equivalents. α,α‐diphenyl‐β‐picrylhydrazyl (DPPH) assay was used to measure antiradical activity of the extracts and it was compared with ascorbic acid.

Maximum fruit extract can be obtained by hand‐macerating the peeled fruit rich in phenolic content 11.1±1.47 mg/g gallic acid equivalent. Its antiradical activity was measured as 16.34±0.81 that was calculated as 10.0±1.24 ascorbic acid equivalent. CCl4 and TA induced comparable oxidative liver damage as measured through hepatic enzymes. A significant (p=0.05) liver recovery was noticed when animals treated with CCl4/TA were fed with CM extracts.

The study reports the protective role of C. myxa in chemically induced fibrosis by carbon tetrachloride (CCl₄) and thioacetamide (TA).

A study was conducted to determine the antioxidative properties of roselle (Hibiscus sabdariffa L.) methanol extract by monitoring the formation of diene‐conjugated compounds and thiobarbituric acid reactive substances (TBARS) in linoleic acid model system. The properties were compared to those of butylated hydroxy‐anisole (BHA) and α‐tocopherol. Results indicated that the roselle extract showed stronger antioxidant properties than BHA or α‐tocopherol. A total of 200 parts per million (ppm) of the extract inhibited more than 85 per cent of diene‐conjugated compounds after seven days of incubation at 40^○C. The total phenolic compound was found to be 2.96mg/g calyx as gallic acid equivalent. This indicates that roselle is a good source of natural antioxidants which may protect the body from damage by free radicals and lipid peroxidation. The protective effect is probably through the action of highly bioavailable ascorbic acid, β‐carotene and phenolic compounds, especially the anthocyanins.

The purpose of this study was to characterise the physiochemical properties of selected exotic seasonal tropical fruits available in Singapore.

A total of 11 seasonal tropical fruits including cempedak, chiku, custard apple, jackfruit, longkong, mangosteen, red jambu, pearl jambu, rambutan, salak and starfruit were analyzed for their sugars, organic acids and free phenolic acids composition using liquid chromatographic methods. Total phenolic content (free and bound), total soluble solids and pH were determined using Folin‐Ciocalteu method, refractometer and pH meter, respectively.

Fructose, glucose and sucrose were the main sugars in all the fruits. Cempedak had the highest sucrose concentration, while custard apple had the highest content of fructose and glucose. Malic and citric acids were the major organic acids in most of the fruits, except for pearl jambu and red jambu where succinic acid was the dominant acid. The total phenolic content varied from 122.94 to 712.20 mg gallic acid equivalent (GAE)/kg fresh weight (FW). Ferulic (0.631 mg/kg) and sinapic acids (1.506 mg/kg) were the predominant free phenolic acids in custard apple, while caffeic acid was the main free phenolic acid in jackfruit, salak and starfruit.

The paper demonstrates that the physiochemical characteristics of the 11 tropical fruits varied markedly, which is responsible for the differential flavour and stability. The findings are useful for epidemiological research and predicting the degree of ripeness, stability and post‐harvest processing required for these fruits.

The study was aimed to explore the potential impact of microwave heating (450 W for 2, 4, 6 and 8 min) on antioxidant activity, anti-nutritional factors, volatile and phenolic compounds of the plum kernels.

Plum kernels are rich in proteins, lipids and bioactive compounds that are mostly underused and undervalued.

The results showed that microwave heating at 450 W for 6 min significantly (p < 0.05) increased the antioxidant activity, total phenolic and flavonoid content, while the longer treatment time (450 W for 8 min) adversely affected the phenolic compounds. Most importantly, the anti-nutritional factors like amygdalin, hydrocyanic acid, phytic acid and tannin content were reduced up to 87.1, 84.7, 20.9 and 46.2%, respectively at 450 W for 6 min treatment conditions, which was confirmed from the larger shifts observed in FT-IR spectra near 1,157 cm⁻¹. Microwave heating at 450 W for 6 min also proved beneficial in improving the bioavailability of volatile and phenolic compounds including chlorogenic acid, gallic acid, syringic acid, (+)-catechin, caffeic acid, ß-carotene, trans-ferulic acid, rutin trihydrate, 3,4-dihydroxybenzoic acid, tannic acid and quercetin by liberating them from the plant matrix.

The results thus indicate that controlled microwave heating could be an effective approach for the reduction of anti-nutritional factors besides leading to an overall improvement in antioxidant potential and volatile and phenolic compounds. This novel technological approach can proliferate the use of plum kernels in different diversified food formulations.

Salak (Salacca zalacca) is a species of palm tree native to Malaysia and Indonesia. The fruit is also known as “snake fruit” due to its reddish‐brown scaly skin. Four different varieties of the fruits (i.e. SS1, SS2, SS3 and SS4) have been established by Sabah State Agriculture Department, Malaysia. The purpose of this paper is to investigate and compare the antioxidant properties and phytochemicals content in the edible portion of the fruits.

Four different varieties of the fruits were collected and analysed for the antioxidant properties (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assay), total phenolic and total flavonoid contents using spectrophotometry analysis. Ascorbic acid was determined using titration method.

The results showed the total phenolic and flavonoid contents of the samples were in the range of 12.6‐15.0 mg gallic acid equivalent/g and 4.9‐7.1 mg catechin equivalent/g of dry sample, respectively. The antioxidant activities of the extracts (using DPPH assay) were highly correlated with total phenolic and moderately correlated with flavonoid content. The reducing capabilities of the extracts using FRAP assay were moderately correlated with all phytochemicals tested. The results suggested that the phytochemicals and antioxidant activity of salak is mildly affected by variety. The high phytochemicals and antioxidant properties of S. zalacca indicated that the fruit possessed potential health benefits properties.

Salak fruit is now being developed into fruit juice, pickle and other food products. The commercialization of the fruit may be enhanced if more knowledge on its potential health benefits is studied and discovered. The economic and nutraceutical values might increase and will contribute greatly to the local people.

The purpose of this paper is to investigate various extracts of Annona squamosa L (Annonanceae) and Carica papaya L (Caricaceae) seeds for their antioxidant activity, free radical scavenging ability, total phenolic and flavonoid contents.

Samples from both the seeds were prepared by subjecting them to microwave‐assisted extraction. After determining their antioxidant properties and polyphenolic contents, correlation between them was also investigated.

Highest antioxidant activity (3,179.66 g gallic acid equivalent/g of dry extract) and phenol content were registered by chloroform:methanol extract of C. papaya seeds. Maximum radical scavenging activity (3,201.63 ascorbic acid equivalent antioxidant capacity g/100 g of dry extract) was exerted by water extract of A. squamosa seeds, whereas acetone extract of C. papaya registered highest flavonoid content among all extracts. Polar extracts were found to be better free radical scavengers compared with those less polar. Hexane extracts showed least DPPH radical scavenging activity. Acetone proved efficient in extracting flavonoids, whereas phenols were best extracted in a mixture of chloroform and methanol. Phenolic metabolites seem to be contributing significantly towards antioxidant activity of the C. papaya extracts, but less so in the case of A. squamosa.

There have been few reports on antioxidant activity of non‐edible parts of commonly consumed fruits. The research indicates that seeds may be a promising source of antioxidants, which may have therapeutic implications.

The purpose of this paper is to investigate the health and medicinal importance of bush tea (Athrixia phylicoides DC) and special tea (Monsonia burkeana Planch. ex Harv), two of Southern African indigenous herbal teas.

The two herbal teas, A. phylicoides and M. burkeana were extracted individually and in combined ratios for analysis. The phenolic content was determined and the different phenolic compounds were identified using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The anti-diabetic activity of the teas was determined by evaluating the inhibition of both α-amylase and α-glucosidase in vitro. The anti-proliferative activity was measured on human cervical cancer (HeLa) cell line using the MTT (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium) assay.

Gallic acid, chlorogenic acid and quercetin were identified to be present in significant quantities by TLC. The HPLC quantified the presence of catechin (1.567 mg/g) and chlorogenic acid (1.862 mg/g) in special tea while chlorogenic acid (1.288 mg/g) was present in bush tea. Bush tea and special tea expressed significant levels of phenolic content and high antioxidant activities. Special tea (S100) expressed high inhibition of α-amylase, α-glucosidase and HeLa cell line proliferation when compared to bush tea (B100).

Both bush tea and special tea could provide an alternative for treatment and management of both diabetes and cervical cancer. However, future studies are needed to investigate their synergistic effect with a wide range of other commercial herbal teas.

The purpose of this paper is to evaluate the antioxidant activity and toxicity of Clinacanthus nutans leaves from three conventional extraction methods, i.e. maceration, Soxhlet and magnetic stirring.

Total flavonoid content (TFC) and phenolic content (TPC) were determined using colorimetric method of aluminum chloride and Folin-Ciocalteu (FC) assay, respectively. Antioxidant property of C. nutans was evaluated using 2,2'-diphenyl-1-pierylhydrazyl (DPPH) free radical scavenging assay. Cytotoxic activity of C. nutans against brine shrimp was evaluated based on LC50 (lethality concentration) after 24 h exposure to the plant extract.

The highest TPC of C. nutans was observed with Soxhlet extraction method (98.87 ± 10.43 mg of gallic acid equivalents (GAE/g) followed by maceration (68.77 ± 2.45 mg of GAE/g) and magnetic stirring (46.75 ± 2.45 mg of GAE/g). Interestingly, remarkable highest TFC was observed with magnetic stirring (568.90 ± 4.85 mg of rutin equivalent (RE)/g) followed by maceration (249.60 ± 2.79 mg of RE/g) and Soxhlet (174.8 ± 1.74 mg of RE/g). On the other hands, the extract obtained using maceration method showed the highest antioxidant activity (IC50: 14.18 mg/mL compared to ascorbic acid 144.36 µg/mL). Cytotoxicity of C. nutans from all extraction methods showed similar LC50 values with maceration (3.81 mg/mL), Soxhlet (2.61 mg/mL) and magnetic stirring (4.56 mg/mL), respectively.

Both phenolic and flavonoids are responsible for the antioxidant activity, of C. nutans extracts. Based on Meyer's toxicity index, all extracts were nontoxic (LC50>1 mg/mL).

The cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total antioxidant capacity (TAC) and chemical constituents of the vegetable oils from seeds of this plant, taking its nutritional value into consideration.

Vegetable oils of different indigenous cowpea varieties were obtained using soxhelt extraction assembly and subjected to GC‐MS analyses and various antioxidant assays including 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulpohonic acid) (ABTS) radical cation scavenging, ferr, 2.2′‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging, total phenolic contents (TPC), lipid peroxidation inhibition, and iron chelation activity.

Various chemical constituents including different hydrocarbons, tocopherols, ketones, fatty esters, estragole and cedrene were identified. TPCs were found to be 5.439, 5.7279, 7.6126, 6.7573 and 10.0591 mg/L gallic acid equivalent for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively. Employing ABTS radical decoloration assay a significant linear correlation (R²=0.997, 0.996, 0.997, 0.996 and 0.997 for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively) was found between the percent inhibition of ABTS radical cation and the amount of vegetable oils. The percent inhibition of the Fe(II)‐Ferrozine complex formation was found to be 29.45, 53.76, 82.91, 86.59 and 57.87 for the same varieties, respectively.

GC‐MS and standard in vitro antioxidative capacity analyses data clearly demonstrated the potency of the cowpea as antioxidant and radical scavenger plant which may be used as a good source of natural antioxidants. The plant seeds may prove a better and cost‐effective substitute of expensive food items.