Displaying publications 1 - 20 of 210 in total

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  1. The antiscorbutic value of tropical foods
    Oliveiro CJ
    Malayan Medical Journal, 1934;9:50-4.
    Matched MeSH terms: Ascorbic Acid
  2. Vitamin C  content of Malayan foods
    Leong PC
    Journal of the Malaya Branch of the British Medical Association, 1939;3:238-257.
    Matched MeSH terms: Ascorbic Acid
  3. A preliminary note on the antiscorbutic value of tropical foods
    Oliveiro CJ
    Malayan Medical Journal, 1932;7:38-45.
    Matched MeSH terms: Ascorbic Acid Deficiency
  4. Ethyl 2-(4-benzyl-3-methyl-6-oxo-1,6-dihydropyridazin-1-yl)acetate: crystal structure and Hirshfeld surface analysis
    Zaoui Y, Ramli Y, Taoufik J, Mague JT, Jotani MM, Tiekink ERT, et al.
    Acta Crystallogr E Crystallogr Commun, 2019 Mar 01;75(Pt 3):392-396.
    PMID: 30867956 DOI: 10.1107/S205698901900241X
    The title compound, C16H18N2O3, is constructed about a central oxopyridazinyl ring (r.m.s. deviation = 0.0047 Å), which is connected to an ethyl-acetate group at the N atom closest to the carbonyl group, and benzyl and methyl groups second furthest and furthest from the carbonyl group, respectively. An approximately orthogonal relationship exists between the oxopyridazinyl ring and the best plane through the ethyl-acetate group [dihedral angle = 77.48 (3)°]; the latter lies to one side of the central plane [the Nr-Nr-Cm-Cc (r = ring, m = methyl-ene, c = carbon-yl) torsion angle being 104.34 (9)°]. In the crystal, both H atoms of the N-bound methyl-ene group form methyl-ene-C-H⋯O(ring carbon-yl) or N(pyridazin-yl) inter-actions, resulting in the formation of a supra-molecular tape along the a-axis direction. The tapes are assembled into a three-dimensional architecture by methyl- and phenyl-C-H⋯O(ring carbon-yl) and phenyl-C-H⋯O(ester carbon-yl) inter-actions. The analysis of the calculated Hirshfeld surface indicates the dominance of H⋯H contacts to the overall surface (i.e. 52.2%). Reflecting other identified points of contact between mol-ecules noted above, O⋯H/H⋯O (23.3%), C⋯H/H⋯C (14.7%) and N⋯H/H⋯N (6.6%) contacts also make significant contributions to the surface.
    Matched MeSH terms: Ascorbic Acid
  5. Note on the effects of nitrate and nitrite upon ascorbic acid in acid solutions
    Lugg JWH
    Med J Malaya, 1950;5.
    1. It is shown that in contradistinction to the marked stability of ascorbic acid in acid solution towards nitrate is its sensitiveness towards nitrite. 2. The primary major product of the action of the nitrite is dehydroascorbic acid, which appears to be relatively stable towards the nitrite. 3. The nutritional and other physiological implications of these findings are discussed.
    Matched MeSH terms: Ascorbic Acid
  6. Some aspects of vitamin C: a review
    Oliveiro CJ
    Malayan Medical Journal, 1932;7:15-8.
    Matched MeSH terms: Ascorbic Acid; Ascorbic Acid Deficiency
  7. Advances in the analytical methods for determining the antioxidant properties of honey: a review
    Moniruzzaman M, Khalil MI, Sulaiman SA, Gan SH
    Afr J Tradit Complement Altern Med, 2012;9(1):36-42.
    PMID: 23983317
    Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. In an effort to combat free radical activity, scientists are studying the effects of increasing individuals' antioxidant levels through diet and dietary supplements. Honey appears to act as an antioxidant in more ways than one. In the body, honey can mop up free radicals and contribute to better health. Various antioxidant activity methods have been used to measure and compare the antioxidant activity of honey. In recent years, DPPH (Diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), ORAC (The Oxygen Radical Absorbance Capacity), ABTS [2, 2-azinobis (3ehtylbenzothiazoline-6-sulfonic acid) diamonium salt], TEAC [6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox)-equivalent antioxidant capacity] assays have been used to evaluate antioxidant activity of honey. The antioxidant activity of honey is also measured by ascorbic acid content and different enzyme assays like Catalase (CAT), Glutathione Peroxidase (GPO), Superoxide Dismutase (SOD). Among the different methods available, methods that have been validated, standardized and widely reported are recommended.
    Matched MeSH terms: Ascorbic Acid/pharmacology
  8. Fulltext Thin layer drying kinetics and quality dynamics of persimmon (Diospyros kaki) treated with preservatives and solar dried under different temperatures
    Khaliq A, Li WF, Ali S, Shah ST, Ma ZH, Mao J, et al.
    PLoS One, 2022;17(3):e0265111.
    PMID: 35353819 DOI: 10.1371/journal.pone.0265111
    Poor postharvest handling, microbial infestation, and high respiration rate are some the factors are responsible for poor storage life of perishable commodities. Therefore, effective preservation of these commodities is needed to lower the damages and extend shelf life. Preservation is regarded as the action taken to maintain desired properties of a perishable commodity as long as possible. Persimmon (Diospyros kaki) is perishable fruit with high nutritive value; however, has very short shelf-life. Therefore, effective preservation and drying is needed to extend its storage life. Drying temperature and preservatives significantly influence the quality of perishable vegetables and fruits during drying. The current study investigated the effect of different temperatures and preservatives on drying kinetics and organoleptic quality attributes of persimmon. Persimmon fruits were treated with preservatives (25% honey, 25% aloe vera, 2% sodium benzoate, 1% potassium metabisulfite, and 2% citric acid solutions) under different drying temperatures (40, 45, and 50°C). All observed parameters were significantly affected by individual effects of temperatures and preservatives, except ash contents. Similarly, interactive effects were significant for all parameters except total soluble sugars, ash contents, and vitamin C. Generally, fruits treated with citric acid and dried under 50°C had 8.2% moisture loss hour-1, 14.9 drying hours, 0.030 g H2O g-1 hr-1, 1.23° Brix of total soluble solids, 6.71 pH, 1.35% acidity, and 6.3 mg vitamin C. These values were better than the rest of the preservatives and drying temperatures used in the study. Therefore, treating fruits with citric acid and drying at 50°C was found a promising technique to extend storage life of persimmon fruits. It is recommended that persimmon fruits dried at 50°C and preserved in citric acid can be used for longer storage period.
    Matched MeSH terms: Ascorbic Acid/analysis
  9. The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis
    Nosratabadi S, Ashtary-Larky D, Hosseini F, Namkhah Z, Mohammadi S, Salamat S, et al.
    Diabetes Metab Syndr, 2023 Aug;17(8):102824.
    PMID: 37523928 DOI: 10.1016/j.dsx.2023.102824
    BACKGROUND AND AIM: It has been suggested that taking vitamin C supplements may improve glycemic control in patients with type 2 diabetes mellitus (T2DM). However, there has not been a thorough evaluation of the actual impact or certainty of the findings. This systematic review and meta-analysis was conducted to determine the effect of vitamin C supplementation on glycemic profile in T2DM patients.

    METHODS: A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis.

    RESULTS: The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels.

    CONCLUSION: These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.

    Matched MeSH terms: Ascorbic Acid/therapeutic use
  10. Fulltext Effectiveness of ascorbic acid and sodium metabisulfite as anti-browning agent and antioxidant on green coconut water (Cocos nucifera) subjected to elevated thermal processing
    Tan, T.C., Cheng, L.H., Bhat, R., Rusul, G., Easa, A.M.
    International Food Research Journal, 2015;22(2):631-637.
    MyJurnal
    Thermal processing of green coconut water (GCW) caused non-enzymic browning and development of rancidity. Effect of the addition of several combinations of ascorbic acid (AA) (0 to 100 ppm) and sodium metabisulfite (SMB) (0 to 30 ppm) on brown discolouration and rancidity of GCW during elevated thermal processing (121°C for 5 min at 15 psi) was investigated. Addition of AA and/or SMB significantly (P
    Matched MeSH terms: Ascorbic Acid
  11. Fulltext Stability of selected quality attributes of pink guava juice during storage at elevated temperatures
    Aishah, B., Hannah, K., Zati Alyani, O.
    International Food Research Journal, 2016;23(5):1918-1925.
    MyJurnal
    Quality degradation is normally judge by monitoring independently the loss of a certain quality
    attribute during storage. However, the rate of degradation for each of the quality attributes
    present in a food product is not the same. This study focus on deterioration of vitamin C,
    lycopene, total phenolics and antioxidant activity of ready-to-drink pink guava juice (PGJ)
    during storage at elevated temperatures. Kinetic order, rate constant (k), activation energy
    (Ea) and temperature coefficient (Q10) of the degradation were derived by applying Arrhenius
    equation. The results obtained showed that freshly made PGJ contain 39.79±2.18 mg/100 mL
    of vitamin C, 3.17±0.27 mg/L of lycopene, 28.08±4.11 mgGAE/100 mL of total phenolic
    content (TPC) and 13.20±1.91 mMTE/100 mL of ferric reducing antioxidant power (FRAP).
    All quality attributes measured in this study showed zero-order kinetic reaction. The results
    also showed that FRAP has the highest Ea of 49.52 KJ/mol and Q10 of 1.80, followed by
    vitamin C (Ea=41.49 KJ/mol; Q10=1.64), lycopene (Ea=31.75 KJ/mol; Q10=1.46), and lastly
    TPC (Ea=14.11 KJ/mol; Q10=1.18). The predicted total depletion of each quality attribute
    at refrigerated storage (5o
    C) were 266 days for antioxidant activity, 158 days for vitamin C
    and lycopene, and 63 days for total phenolics. This study provide useful information on the
    degradation rate and availability of health beneficial and bioactive compounds present in fruit
    juice beverage during storage.
    Matched MeSH terms: Ascorbic Acid
  12. Effect of preculture, pvs2 and vitamin C on survival of recalcitrant Nephelium ramboutan-ake shoot tips after cryopreservation by vitrification
    Chua SP, Normah MN
    Cryo Letters, 2011 Nov-Dec;32(6):506-15.
    PMID: 22227711
    This paper reports the cryopreservation of Nephelium ramboutan-ake shoot tips derived from in vitro shoot multiplication and in vitro seed germination using vitrification. Preculture with either 0.5 M sucrose for 2 days or a combination of 0.3 M sucrose and 0.5 M glycerol for 3 days enhanced dehydration tolerance and resulted in the highest survival of shoot tips; however, none of the shoot tips withstood liquid nitrogen (LN) exposure. The use of a lower temperature (0 degree C) during exposure to plant vitrification solution (PVS2) led to higher survival of shoot tips, compared to exposure at 25 degree C. The survival percentage of shoot tips exposed to PVS2 for up to 20 min at 0°C was 83.3 percent. It was only 53.3 percent when shoot tips were exposed to PVS2 at 25 degree C for 5 min. The importance of vitamin C for reducing oxidative stress in shoots tips was demonstrated. The addition of 0.28 mM vitamin C during critical steps of the vitrification process resulted in a high survival (96.7 percent) without LN exposure, compared to 73.3 percent for shoot tips not treated with vitamin C. Moreover, 3.3 percent shoot tips withstood LN exposure when vitamin C was added during the loading step. This result suggests that cryopreservation is possible for this tropical, recalcitrant seeded tree species.
    Matched MeSH terms: Ascorbic Acid*
  13. The depletion effects of chlorpromazine, reserpine and ascorbic acid on tissue histamine of guinea-pigs
    Ridzwan BH, Jais AM, Waton NG
    Gen. Pharmacol., 1988;19(4):631-6.
    PMID: 3410287
    1. 30 mg kg-1 chlorpromazine (CPZ) depleted more than half of the tissue histamine from lungs, stomach, ileum and skin of the normal guinea-pigs. However, the drug increased the tissue histamine content in scorbutic animals. 2. In contrast, reserpine depleted histamine from the four tested tissues in both normal and scorbutic animals, except those in the lungs of the control animals. 3. Ascorbic acid only depleted histamine from the stomach and ileum. 4. A 24 hr period was the time limit for CPZ to deplete the histamine in all the four tested tissues. 5. Histamine partially or completely recovered in the tissues after the next 24 hr.
    Matched MeSH terms: Ascorbic Acid/pharmacology*
  14. A note concerning the possibility that the lesions in scurvy are due to a failure to produce 'compact' collagen fibres
    Candlish J
    Med J Malaya, 1966 Dec;21(2):161-3.
    PMID: 4227387
    Matched MeSH terms: Ascorbic Acid/pharmacology*
  15. Exogenous chlorogenic acid inhibits quality deterioration in fresh-cut potato slices
    You W, Wang C, Zhang J, Ru X, Xu F, Wu Z, et al.
    Food Chem, 2024 Jul 15;446:138866.
    PMID: 38430769 DOI: 10.1016/j.foodchem.2024.138866
    Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.
    Matched MeSH terms: Ascorbic Acid/metabolism
  16. Fulltext Functional properties of Phaleria Macrocarpa fruit flesh at different ripeness
    Ahmed Asrity, S.M., Tsan, F.Y., Ding, P., Syed Aris, S.R.
    International Food Research Journal, 2018;25(3):1273-1280.
    MyJurnal
    Functional property changes in Phaleria macrocarpa fruit during ripening on tree were studied. Results showed that juice extracted from fruit flesh had low acidity and soluble solid content. Fruit acidity decreased but soluble solids increased as the fruit ripened. In terms of antioxidant content, ascorbic acid, DPPH free radical scavenging activities and total phenolic content were, however, the lowest in fully ripe fruit flesh while the unripe fruit flesh had the highest. High percentage of these antioxidants was water soluble. This study suggests that the unripe fruits should be harvested for valuable medicinal product development instead of the fully ripe fruits.
    Matched MeSH terms: Ascorbic Acid
  17. Fulltext Vibration-assisted forward osmosis process for Mao (Antidesma bunius L. Spreng) juice concentration: water flux enhancement and preservation of phytochemicals
    Sirinupong, T., Tirawat, D., Lau, W. J., Youravong, W.
    International Food Research Journal, 2020;27(6):1156-1166.
    MyJurnal
    The experimental water flux of the forward osmosis (FO) process is much lower than the
    theoretical flux due to the existence of the internal concentration polarisation (ICP), external
    concentration polarisation (ECP), and membrane fouling. In the present work, vibration was
    integrated with the FO process to enhance water flux in water and Mao (Antidesma bunius L.
    Spreng) juice concentration. In addition, the capability of the FO process in preserving
    phytochemicals was studied. The use of the vibration assisted technique could enhance the
    water flux up to 23% during the FO process of distilled water due to the reduction of ICP, and
    a much higher water flux enhancement (up to 70%) was attained during the FO of Mao juice
    due to the reduction of ICP, ECP, and fouling. Phytochemicals including total phenolic
    compounds, anthocyanin, and ascorbic acid were preserved up to 82.7, 72.6, and 95.9%,
    respectively. These results suggest that membrane vibration is a promising technique for the
    enhancement of the FO process performance.
    Matched MeSH terms: Ascorbic Acid
  18. Fulltext EFFECTS OF DIFFERENTEXPOSURE TIMES OF LED LIGHTS ON POSTHARVEST PERFORMANCES OF FRESH-CUT PINEAPPLE(Ananas comosusL. cv. Josapine)
    LEONG JIA Q, WAN ZALIHA WAN SEMBOK
    UMT Journal of Undergraduate Research, 2019;1(1):68-79.
    MyJurnal
    Pineapple is one of the most important commercial fruit crops served in fresh-cut form which is convenientfor the consumers. However, fresh-cut pineapple induces the activity of phenolic compounds which triggers the generation of brown or dark pigments. Browning incidence (BI) directly influences the fruit’s acceptability and marketability. Therefore, different exposure times (5mins, 10mins, 15mins and 20mins)and typesof LED lights (white, red and blue) were applied on fresh-cut pineapple stored at 5oC storage for twelve days to reduce BI. A significant interaction between the two factors was recorded in lightness coefficient, chroma, total phenolic and ascorbic acid (AA)contents. Regardless of exposure times, all types of LED lights, mainly the blue light, succeeded in delaying BI in fresh-cut pineapple. In conclusion, blue light had a tendency todelay BI andmaintaintheother postharvest quality attributes of fresh-cut pineapple.
    Matched MeSH terms: Ascorbic Acid
  19. Fulltext Keterlibatan aktiviti di kolej kediaman dan perkaitannya terhadap status pemakanan dalam kalangan pelajar Universiti Kebangsaan Malaysia (UKM) kampus Kuala Lumpur
    Noor Farhana Nazri, Ruzita Abdul Talib
    Jurnal Sains Kesihatan Malaysia, 2013;11(2):9-17.
    MyJurnal
    Kajian berbentuk hirisan lintang ini dijalankan untuk mengkaji hubungan antara keterlibatan aktiviti di kolej kediaman dengan status pemakanan pelajar Universiti Kebangsaan Malaysia (UKM) Kuala Lumpur dan menentukan tabiat makan pelajar serta kebolehdapatan makanan sihat di sekitar mereka. Seramai 106 pelajar tahun dua hingga empat UKM Kuala Lumpur terlibat dalam kajian ini (20.8% lelaki dan 79.2% perempuan). Data pengambilan makanan subjek direkod dengan menggunakan diari makanan tiga hari. Keterlibatan subjek dalam aktiviti kolej dan juga kebolehdapatan makanan sihat ditentukan dengan menggunakan borang soal selidik yang dibentuk khas untuk kajian ini. Berat badan, ketinggian, ukurlilit pinggang, peratus lemak tubuh dan Indeks Jisim Tubuh (IJT) juga diukur. Hasil kajian menunjukkan majoriti daripada subjek (62.3%) terlibat secara aktif dengan aktiviti yang diadakan di kolej kediaman. Daripada peratusan ini, 5.3% daripada subjek lelaki dan 31.9% perempuan adalah kurang berat badan. 68.4% subjek lelaki dan 55.3% perempuan mempunyai berat badan normal. 21% subjek lelaki dan 8.5% perempuan adalah pra obes. Tambahan pula, 5.3% (n = 1) subjek lelaki dan 4.3% (n = 2) daripada subjek perempuan tergolong dalam klasifi kasi IJT obes. Kajian ini mendapati majoriti subjek bersetuju bahawa mudah untuk memperolehi makanan sihat di kampus. Terdapat korelasi positif yang signifi kan di antara pengambilan tenaga (r = 0.352, p < 0.05) dan lemak (r = 0.391, p < 0.05) dengan Indeks Jisim Tubuh (IJT) bagi penglibatan terhadap aktiviti kolej yang kurang daripada tiga jam. Bagi penglibatan terhadap aktiviti kolej yang lebih daripada tiga jam pula, terdapat korelasi positif yang signifi kan di antara pengambilan tenaga (r = 0.678, p < 0.01), lemak (r = 0.550, p < 0.05), karbohidrat (r = 0.685, p < 0.01), protein (r = 0.465, p < 0.05), kalsium (r = 0.357, p < 0.05), ferum (r = 0.500, p < 0.05), vitamin A (r = 0.733, p < 0.01) dan vitamin E (r = 0.582, p < 0.05) dengan IJT. Pencapaian ‘Recommended Nutrient Intake’ (RNI) bagi pengambilan tenaga, kalsium, ribofl avin, vitamin C dan vitamin E adalah lebih tinggi bagi subjek yang terlibat dengan aktiviti kolej kurang daripada tiga jam berbanding dengan subjek yang terlibat dengan aktiviti kolej lebih daripada tiga jam. Kesimpulannya, walaupun ramai subjek yang aktif, masih terdapat dalam kalangan mereka yang mengalami masalah kurang berat badan, lebih berat badan dan obes. Oleh yang demikian, penglibatan dalam aktiviti di kolej kediaman memberi kesan kepada status pemakanan pelajar Universiti Kebangsaan Malaysia.
    Matched MeSH terms: Ascorbic Acid
  20. Fulltext The effect of storage on the quality attributes of ultraviolet-irradiated and thermally pasteurised pineapple juices
    Chia, S. L., Rosnah, S., Noranizan, M. A., Wan Ramli, W. D.
    International Food Research Journal, 2012;19(3):1001-1010.
    MyJurnal
    The effect of storage time on the quality of ultraviolet-irradiated and thermally pasteurised pineapple juice was evaluated. The juices were irradiated with ultraviolet light (UV-C) at wavelength 254 nm (53.42 mJ/cm2, 4.918 s), thermally pasteurised at 800C for 10 minutes and stored at 40C for 13 weeks. There were significant changes in the total soluble solids, pH, titratable acidity and turbidity of UV-irradiated juice during storage, whereas for the same quality attributes of thermally pasteurised juice remained stable throughout the storage time. There were no significant changes in total phenolics for both treatments throughout the storage period. Other quality parameters (ascorbic acid, colour L, hue angle and chroma) were significantly affected by the storage time. Regarding the microbiological analysis, the total plate counts and yeast and mould counts of the UV-irradiated juice increased gradually throughout the 13 weeks of storage while these parameters remained unchanged in the thermally pasteurised juice with almost no microorganism growth. UV-irradiated pineapple juice preserved better quality attributes (TSS, pH, titratable acidity, ascorbic acid, turbidity, total phenolic, L (lightness), hue angle and chroma) than the thermal pasteurised juice during the storage time. Hence, UV irradiation has great potential as an alternative technology to thermal pasteurisation in producing products of high nutritive values.
    Matched MeSH terms: Ascorbic Acid
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