Displaying publications 1 - 20 of 69 in total

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  1. Musa KH, Abdullah A, Al-Haiqi A
    Food Chem, 2016 Mar 1;194:705-11.
    PMID: 26471610 DOI: 10.1016/j.foodchem.2015.08.038
    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.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  2. Taha M, Ismail NH, Jamil W, Yousuf S, Jaafar FM, Ali MI, et al.
    Molecules, 2013 Sep 05;18(9):10912-29.
    PMID: 24013406 DOI: 10.3390/molecules180910912
    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).
    Matched MeSH terms: Biphenyl Compounds/chemistry
  3. Assaggaf H, Jeddi M, Mrabti HN, Ez-Zoubi A, Qasem A, Attar A, et al.
    Sci Rep, 2024 Apr 22;14(1):9195.
    PMID: 38649707 DOI: 10.1038/s41598-024-59708-x
    The development of novel antioxidant compounds with high efficacy and low toxicity is of utmost importance in the medicine and food industries. Moreover, with increasing concerns about the safety of synthetic components, scientists are beginning to search for natural sources of antioxidants, especially essential oils (EOs). The combination of EOs may produce a higher scavenging profile than a single oil due to better chemical diversity in the mixture. Therefore, this exploratory study aims to assess the antioxidant activity of three EOs extracted from Cymbopogon flexuosus, Carum carvi, and Acorus calamus in individual and combined forms using the augmented-simplex design methodology. The in vitro antioxidant assays were performed using DPPH and ABTS radical scavenging approaches. The results of the Chromatography Gas-Mass spectrometry (CG-MS) characterization showed that citral (29.62%) and niral (27.32%) are the main components for C. flexuosus, while D-carvone (62.09%) and D-limonene (29.58%) are the most dominant substances in C. carvi. By contrast, β-asarone (69.11%) was identified as the principal component of A. calamus (30.2%). The individual EO exhibits variable scavenging activities against ABTS and DPPH radicals. These effects were enhanced through the mixture of the three EOs. The optimal antioxidant formulation consisted of 20% C. flexuosus, 53% C. carvi, and 27% A. calamus for DPPHIC50. Whereas 17% C. flexuosus, 43% C. carvi, and 40% A. calamus is the best combination leading to the highest scavenging activity against ABTS radical. These findings suggest a new research avenue for EOs combinations to be developed as novel natural formulations useful in food and biopharmaceutical products.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  4. Md Yusoff MH, Shafie MH
    Anal Chim Acta, 2024 Dec 01;1331:343351.
    PMID: 39532430 DOI: 10.1016/j.aca.2024.343351
    BACKGROUND: The extraction of polysaccharides using an acidic extraction media has been extensively reported, highlighting its effectiveness in yielding high-quality polysaccharides. A higher concentration of acidic solution could hydrolyze the structure of polysaccharide, while a low concentration reduces the extraction efficiency. Despite this challenges, deep eutectic solvents (DES) were introduced as an alternative extraction medium due to additional interactions such as inter and intra-molecular interactions, Van de Waals, hydrogen bond, and electrostatic interactions, which could improve the polysaccharide extraction efficiency and biological activities. Furthermore, the extraction conditions such as extraction medium and extraction parameters could affect the properties of polysaccharides as well as influence their structure-activity relationship for biological activities.

    RESULTS: The result showed that the microwave-assisted extraction of Micromelum minutum leaf polysaccharide (MMLP) using DES as an extraction media (MMLP-DES) gave a higher yield (improvement of 101.20 %) than citric acid monohydrate (CAM) (MMLP-CAM) and required a lower percentage of microwave power (19.83 % less) and time (0.78 min less). The properties of MMLPs significantly differ based on their pH, molecular weight, viscosity, degree of esterification and monosaccharide molar ratio which influenced the biological activities. Compared to MMLP-CAM, MMLP-DES had a more branched and less linear structure. The bioactivities study revealed that MMLP-DES exhibited higher antioxidant and anti-α-amylase activities (i.e.

    , DPPH: 74.52 %, FRAP: 2.87 mM FeSO4 and α-amylase inhibition: 86.23 %) compared to MMLP-CAM (i.e.

    , DPPH: 49.33 %, FRAP: 1.49 mM FeSO4, and α-amylase inhibition: 81.76 %). The mechanism and structure-activity relationship of MMLPs on bioactivities were also hypothesized.

    SIGNIFICANCE: Based on our previous study, the citric acid monohydrate-glycerol based DES as an extraction medium has enhanced the extraction yield of polysaccharides from M. minutum. This study highlights the DES combined with microwave-assisted extraction to improve the yield of MMLP and evaluate the biological activities compared to CAM as a classical solvent. In conclusion, the DES showed the advantages for extraction of polysaccharides with desired biological activities.

    Matched MeSH terms: Biphenyl Compounds/chemistry
  5. Hashim SE, Sirat HM, Yen KH, Ismail IS, Matsuki SN
    Nat Prod Commun, 2015 Sep;10(9):1561-3.
    PMID: 26594759
    Seven compounds were isolated from the n-hexane and chloroform extracts of the flowers and leaves of four Hornstedtia species and their structures were identified using spectroscopic techniques as 3,7,4'-trimethylkaempferol (1), 3,7-dimethylkaempferol (2), 7,4'-dimethylkaempferol (3), 3,5-dimethylkaempferol (4), 3-methylkaempferol (5), stigmast-4-en-3-one (6), and 6-hydroxy-stigmast-4-en-3-one (7). Compounds 1 to 7 were isolated from these species for the first time. They were assayed for free radical scavenging and α-glucosidase inhibition activities. The DPPH assay showed that 3-methylkaempferol (5) was the most potent antioxidant agent with an IC50 value 78.6 µM, followed by 7,4'-dimethylkaempferol (3) (IC50 = 86.1 µM). For α-glucosidase inhibition activity, 3-methylkaempferol (5) exhibited significant inhibitory activity with an IC50 value 21.0 µM. The present study revealed that Hornstedtia species have potential activities as antioxidant and α-glucosidase inhibitors.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  6. Ho SK, Tan CP, Thoo YY, Abas F, Ho CW
    Molecules, 2014 Aug 19;19(8):12640-59.
    PMID: 25153876 DOI: 10.3390/molecules190812640
    Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p>0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  7. Kumar CS, Loh WS, Ooi CW, Quah CK, Fun HK
    Molecules, 2013 Sep 26;18(10):11996-2011.
    PMID: 24077177 DOI: 10.3390/molecules181011996
    A series of six novel heterocyclic chalcone analogues 4(a-f) has been synthesized by condensing 2-acetyl-5-chlorothiophene with benzaldehyde derivatives in methanol at room temperature using a catalytic amount of sodium hydroxide. The newly synthesized compounds are characterized by IR, mass spectra, elemental analysis and melting point. Subsequently; the structures of these compounds were determined using single crystal X-ray diffraction. All the synthesized compounds were screened for their antioxidant potential by employing various in vitro models such as DPPH free radical scavenging assay, ABTS radical scavenging assay, ferric reducing antioxidant power and cupric ion reducing antioxidant capacity. Results reflect the structural impact on the antioxidant ability of the compounds. The IC₀ values illustrate the mild to good antioxidant activities of the reported compounds. Among them, 4f with a p-methoxy substituent was found to be more potent as antioxidant agent.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  8. Musa KH, Abdullah A, Kuswandi B, Hidayat MA
    Food Chem, 2013 Dec 15;141(4):4102-6.
    PMID: 23993591 DOI: 10.1016/j.foodchem.2013.06.112
    A stable chromogenic radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) is commonly used for the determination of antioxidant activity. In this paper, DPPH was dried into 96 well microplate to produce DPPH dry reagent array plate, based on which the highly sensitive and high throughput determination of antioxidant activities was achieved. The spectrophotometric characterization of the microplate containing dried or fresh DPPH free radicals was reported. The response of the DPPH dry reagent array towards different standard antioxidants was studied. The reaction for DPPH in fresh or dry reagent array with Trolox was reported and compared. The DPPH dry reagent array was used to study the antioxidant activity of banana, green tea, pink guava, and honeydew and the results were compared to the samples reacted with freshly prepared DPPH. The proposed method is comparable to the classical DPPH method, more convenient, simple to operate with minimal solvent required and excellent sensitivity.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  9. Bordbar S, Ebrahimpour A, Abdul Hamid A, Abdul Manap MY, Anwar F, Saari N
    Biomed Res Int, 2013;2013:849529.
    PMID: 23586061 DOI: 10.1155/2013/849529
    The stone fish (Actinopyga lecanora) ethanolic and methanolic tissue extracts were investigated for total phenolic contents (TPCs) as well as antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Both extracts showed low amount of phenolics (20.33 to 17.03 mg of gallic acid equivalents/100 g dried sample) and moderate antioxidant activity (39% to 34% DPPH(•) radical scavenging activity and 23.95 to 22.30 mmol/100 mL FeSO4 FRAP value). Enzymatic proteolysis was carried out in order to improve the antioxidant activity using six commercially available proteases under their optimum conditions. The results revealed that the highest increase in antioxidant activity up to 85% was obtained for papain-generated proteolysate, followed by alcalase (77%), trypsin (75%), pepsin (68%), bromelain (68%), and flavourzyme (50%) as measured by DPPH(•) radical scavenging activity, whilst for the FRAP value, the highest increase in the antioxidant activity up to 39.2 mmol/100 mL FeSO4 was obtained for alcalase-generated proteolysate, followed by papain (29.5 mmol/100 mL FeSO4), trypsin (23.2 mmol/100 mL FeSO4), flavourzyme (24.7 mmol/100 mL FeSO4), bromelain (22.9 mmol/100 mL FeSO4), and pepsin (20.8 mmol/100 mL FeSO4). It is obvious that proteolysis of stone fish tissue by proteolytic enzymes can considerably enhance its antioxidant activity.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  10. Khalil MI, Sulaiman SA, Alam N, Moniruzzaman M, Bai'e S, Man CN, et al.
    Molecules, 2012 Jan 11;17(1):674-87.
    PMID: 22237682 DOI: 10.3390/molecules17010674
    This study was conducted to evaluate the effects of evaporation, gamma irradiation and temperature on the total polyphenols, flavonoids and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities of Tualang honey samples (n = 14) following storage over three, six or twelve months. The mean polyphenol concentrations of the six gamma irradiated honey samples at three, six and twelve months, respectively, were 96.13%, 98.01% and 102.03% higher than the corresponding values of the eight non-gamma irradiated samples. Similarly, the mean values for flavonoids at three, six and twelve months were 111.52%, 114.81% and 110.04% higher, respectively, for the gamma irradiated samples. The mean values for DPPH radical-scavenging activities at three, six and twelve months were also 67.09%, 65.26% and 44.65% higher, respectively, for the gamma irradiated samples. These data indicate that all gamma irradiated honey samples had higher antioxidant potential following gamma irradiation, while evaporation and temperature had minor effects on antioxidant potential.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  11. Bhat R, Khalil HP, Karim AA
    C. R. Biol., 2009 Sep;332(9):827-31.
    PMID: 19748457 DOI: 10.1016/j.crvi.2009.05.004
    This study was conducted to evaluate the potential antioxidant activity of lignin obtained from black liquor, a hazardous waste product generated during the extraction of palm oil. Antioxidant potential of the extracted lignin was evaluated by dissolving the extracted samples in 2 different solvent systems, namely, 2-methoxy ethanol and DMSO. Results revealed high percent inhibition of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in the lignin sample dissolved in 2-methoxy ethanol over DMSO (concentration range of 1-100 microg/ml). Lignin extracted in 2-methoxy ethanol exhibited higher inhibition percentage (at 50 microg/ml, 84.2%), whereas a concentration of 100 microg/ml was found to be effective in the case of the DMSO solvent (69.8%). Fourier transform infrared (FTIR) spectrometry revealed that the functional groups from the extracted lignin and commercial lignin were highly similar, indicating the purity of the lignin extracted from black liquor. These results provide a strong basis for further applications of lignin in the food industry and also illustrate an eco-friendly approach to utilize oil palm black liquor.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  12. Alzorqi I, Sudheer S, Lu TJ, Manickam S
    Ultrason Sonochem, 2017 Mar;35(Pt B):531-540.
    PMID: 27161557 DOI: 10.1016/j.ultsonch.2016.04.017
    Ganoderma mushroom cultivated recently in Malaysia to produce chemically different nutritional fibers has attracted the attention of the local market. The extraction methods, molecular weight and degree of branching of (1-3; 1-6)-β-d-glucan polysaccharides is of prime importance to determine its antioxidant bioactivity. Therefore three extraction methods i.e. hot water extraction (HWE), soxhlet extraction (SE) and ultrasound assisted extraction (US) were employed to study the total content of (1-3; 1-6)-β-d-glucans, degree of branching, structural characteristics, monosaccharides composition, as well as the total yield of polysaccharides that could be obtained from the artificially cultivated Ganoderma. The physical characteristics by HPAEC-PAD, HPGPC and FTIR, as well as the antioxidant in vitro assays of DPPH scavenging activity and ferric reducing power (FRAP) indicated that (1-3; 1-6)-β-d-glucans of Malaysian mushroom have better antioxidant activity, higher molecular weight and optimal degree of branching when extracted by US in comparison with conventional methods.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  13. Ahmad NA, Jumbri K, Ramli A, Abd Ghani N, Ahmad H, Lim JW
    Molecules, 2018 Dec 05;23(12).
    PMID: 30563037 DOI: 10.3390/molecules23123201
    The antiradical efficiency (AE) and kinetic behavior of a new ferulate-based protic ionic liquids (PILs) were described using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The reduction of the DPPH free radical (DPPH•) was investigated by measuring the decrease in absorbance at 517 nm. The time to reach steady state for the reaction of parent acid (ferulic acid) and synthesized PILs with DPPH• was continuously recorded for 1 h. Results revealed that the AE of 2-butylaminoethanol ferulate (2BAEF), 3-dimethylaminopropanol ferulate (3DMAPF) and 3-diethylaminopropanol ferulate (3DEAPF) PILs have improved compared to ferulic acid (FA) as the reaction class changes from low to medium. This attributed to the strong hydrogen abstraction occurred in the PILs. Furthermore, these PILs were found to have a good kinetic behavior compared to FA due to the high rate constant (k₂) (164.17, 242.84 and 244.73 M-1 s-1, respectively). The alkyl chain length and more alkyl substituents on the nitrogen atom of cation were believed to reduce the cation-anion interaction and speed up the hydrogen atom transfer (HAT) and electron transfer (ET) mechanisms; hence, increased rate constant was observed leading to a strong antioxidant activity of the synthesized PILs.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  14. Mogadem A, Almamary MA, Mahat NA, Jemon K, Ahmad WA, Ali I
    Molecules, 2021 Feb 12;26(4).
    PMID: 33673263 DOI: 10.3390/molecules26040979
    The current research is focused on studying the biological efficacy of flexirubin, a pigment extracted from Chryseobacterium artocarpi CECT 8497.Different methods such as DPPH, H2O2, NO•, O2•-, •OH, lipid peroxidation inhibition by FTC and TBA, ferric reducing and ferrous chelating activity were carried out to evaluate the antioxidant activity of flexirubin. Molecular docking was also carried out, seeking the molecular interactions of flexirubin and a standard antioxidant compound with SOD enzyme to figure out the possible flexirubin activity mechanism. The new findings revealed that the highest level of flexirubin exhibited similar antioxidant activity as that of the standard compound according to the H2O2, •OH, O2•-, FTC and TBA methods. On the other hand, flexirubin at the highest level has shown lower antioxidant activity than the positive control according to the DPPH and NO• and even much lower when measured by the FRAP method. Molecular docking showed that the interaction of flexirubin was in the binding cavity of the SOD enzyme and did not affect its metal-binding site. These results revealed that flexirubin has antioxidant properties and can be a useful therapeutic compound in preventing or treating free radical-related diseases.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  15. Nursakinah I, Zulkhairi HA, Norhafizah M, Hasnah B, Zamree MS, Farrah SI, et al.
    Malays J Nutr, 2012 Dec;18(3):363-71.
    PMID: 24568077 MyJurnal
    The objective of this study was to determine antioxidant potential of Garcinia atroviridis leaves and fruits extracts in vitro.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  16. Salleh WMNHW, Anuar MZA, Khamis S, Nafiah MA, Sul'ain MD
    Nat Prod Res, 2021 Jul;35(13):2279-2284.
    PMID: 31544509 DOI: 10.1080/14786419.2019.1669027
    The chemical composition of the essential oil of Knema kunstleri Warb. (Myristicaceae) was investigated for the first time. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 36 components were identified in the essential oil, which made up 91.7% of the total oil. The essential oil is composed mainly of β-caryophyllene (23.2%), bicyclogermacrene (9.6%), δ-cadinene (7.3%), α-humulene (5.7%), and germacrene D (4.3%). The essential oil showed moderate activity towards DPPH free-radical scavenging and lipoxygenase inhibition. To the best of our knowledge, this is the first study of the composition and bioactivities of the essential oil report concerning the genus Knema.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  17. Kassim NK, Lim PC, Ismail A, Awang K
    Food Chem, 2019 Jan 30;272:185-191.
    PMID: 30309531 DOI: 10.1016/j.foodchem.2018.08.045
    The application of preparative thin layer chromatography-2,2-diphenyl-1-picrylhydrazyl (PTLC-DPPH) bioautography technique successfully isolated a lignan sesamin (1), two prenylated coumarins (2 and 3) and a marmesin glycosides (4) from Micromelum minutum methanol bark extract. Compounds 2 and 3 were identified as new compounds whereas 1 and 4 were first isolated from Micromelum genus. Structural identification of all compounds were done by detailed spectroscopic analyses and comparison with literature data. Antioxidant capacities of extract, active fraction and compounds were measured based on DPPH free radical savenging activity, oxygen radical absorbance capacity (ORAC) and β-carotene bleaching. The DPPH activity of methanol extract and its fraction present the IC50 values of 54.3 and 168.9 µg/mL meanwhile the β-carotene bleaching results were 55.19% and 5.75% respectively. The ORAC measurements of M. minutum extract, compounds 2 and 4 showed potent antioxidant activity with the values of 5123, 5539 and 4031 µmol TE/g respectively.
    Matched MeSH terms: Biphenyl Compounds/chemistry*
  18. Ahmad M, Masood S, Sultana S, Hadda TB, Bader A, Zafar M
    Pak J Pharm Sci, 2015 Jan;28(1):241-7.
    PMID: 25553701
    Nutritional quality and antioxidant capacity of three edible wild berries (Rubus ellipticus Smith, Rubus niveus Thunb, Rubus ulmifolius L.) from Lesser Himalayan Range (LHR) were evaluated. Their edible portion was assayed for moisture, fats, ash, carbohydrates, proteins, fibers, essential minerals (Ca, P, Mg, K, Na, Cl, S, Mn, Zn, Fe, Cu, Se, Co, Ni) and DPPH free radical scavenging activity was applied to determine the antioxidant potential. The fruit of Rubus ulmifolius L. (blackberry) possessed the highest values of energy (403.29 Kcal), total protein (6.56g/100 g), Nitrogen (N) content (1500mg/100g), K (860.17mg/100g), Ca (620.56mg/100g), Zn (17.509mg/100g) and the strongest antioxidant activity (98.89% inhibition). While the raspberries (Rubus ellipticus Smith, Rubus niveus Thunb.) exhibited more significant contents of dietary fiber (5.90g/100g), carbohydrates (86.4 g/100 g) and Fe (4.249mg/100g). Significant variation was observed among the tested samples in all the investigated features. The combination of bio elements and active antioxidants clearly showed the applicability of these berries as a nutraceutical supplement.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  19. Li KS, Ali A, Muhammad II
    Acta Sci Pol Technol Aliment, 2017 Jul-Sep;16(3):283-292.
    PMID: 29055976 DOI: 10.17306/J.AFS.0497
    BACKGROUND: Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high percentage of α-linoleneic acid, which may have a high potential in food and pharmaceutical applica- tions. The main objective of this study was to evaluate the influence of microwave (MW) cooking on the proximate composition and antioxidant activity of perah seeds.

    METHODS: In this study, the proximate composition and amygdalin concentration of MW ir- radiated perah seeds were determined. The total phenolic content (TPC), Maillard reaction products (MRPs) and antioxidant activity of methanol (PME), 70% methanol in water (PMW), ethanol (PEE), 70% ethanol  in water (PEW) extracts and methanol extract of oil (PMO) were evaluated during MW cooking. The anti- oxidant activity was evaluated using multiple assays, namely DPPH radical scavenging activity, β-Carotene bleaching assay, and reducing power.

    RESULTS: Microwave cooking did not significantly increase crude lipid and carbohydrate content, and the amounts of other nutrients such as ash, crude protein and fibre remained almost unchanged. As evaluated  by HPLC, the amygdalin concentration in the seeds was reduced by MW cooking. The TPC, MRP and anti- oxidant activity of the solvent extracts of perah seeds increased significantly with increasing roasting time. Of all the extracts, PMW at all MW cooking times displayed the highest antioxidant effectiveness. However, thermal treatment significantly reduced the antioxidant properties of PMO. The values for TPC, MRP and antioxidant effectiveness of the samples were ranked in the following order: PMW > PEW > PME > PEE > PMO, in both control and microwaved samples.

    CONCLUSIONS: In determining the overall quality of the products, MW cooking time was found to be a critical factor. Solubilization of phenolic compounds and formation of MRPs during MW cooking could have caused the increase in antioxidant activity of the perah seeds.
    Matched MeSH terms: Biphenyl Compounds/chemistry
  20. Zakaria SM, Kamal SMM, Harun MR, Omar R, Siajam SI
    Molecules, 2017 Jul 03;22(7).
    PMID: 28671617 DOI: 10.3390/molecules22071105
    Chlorella sp. microalgae is a potential source of antioxidants and natural bioactive compounds used in the food and pharmaceutical industries. In this study, a subcritical water (SW) technology was applied to determine the phenolic content and antioxidant activity of Chlorella sp. This study focused on maximizing the recovery of Chlorella sp. phenolic content and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as a function of extraction temperature (100-250 °C), time (5-20 min) and microalgae concentration (5-20 wt. %) using response surface methodology. The optimal operating conditions for the extraction process were found to be 5 min at 163 °C with 20 wt. % microalgae concentration, which resulted in products with 58.73 mg gallic acid equivalent (GAE)/g phenolic content and 68.5% inhibition of the DPPH radical. Under optimized conditions, the experimental values were in close agreement with values predicted by the model. The phenolic content was highly correlated (R² = 0.935) with the antioxidant capacity. Results indicated that extraction by SW technology was effective and that Chlorella sp. could be a useful source of natural antioxidants.
    Matched MeSH terms: Biphenyl Compounds/chemistry
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