Fairuzeta Ja'afar

Dr. Fairuzeta Ja'afar

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 May 2018 in Food Science & Nutrition
Verified
Journal Article
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NGNurul Aqilah A. Ghani
Nurul Aqilah A. Ghani
ACAmy‐Arniza Channip
Amy‐Arniza Channip
PHPhoebe Chok Hwee Hwa
Phoebe Chok Hwee Hwa
FJFairuzeta Ja'afar
Fairuzeta Ja'afar
HYHartini Mohd Yasin
Hartini Mohd Yasin
Anwar UsmanAnwar Usman
Anwar Usman
Different from cooking oils which contain long‐chain fatty acids, virgin coconut oil (VCO) has high medium‐chain fatty acids, making it a potential functional food which can provide some health benefits. In this study, our objective is to investigate the physicochemical properties, antioxidant capacity, and metal contents of the VCO extracted through four different processing methods: chilling and centrifugation; fermentation; direct micro expelling‐oven dried; and direct micro expelling‐sun‐dried processes. We found that the physicochemical properties, including moisture content, refractive index, viscosity, iodine value, saponification value, peroxide value, free fatty acid, and fatty acid content, of all the VCO conform to the Asian and Pacific Coconut Community (APCC) standard. All of the VCO predominantly contains lauric acid which is in the range of 48.40%–52.84% of the fatty acid content. The total phenolic content and DPPH radical‐scavenging activity (IC50) of the VCO was obtained to be in the range of 1.16–12.54 mg gallic acid equivalents (GAE)/g and 7.49–104.52 mg/ml, respectively, and the metal contents in the VCO were within the acceptable range of the recommended APCC limit. These findings ensure good quality and safety assurance of the VCO produced from the coconut grown in Brunei Darussalam through the different processing methods.

1 September 2019 in Heliyon
Verified
Journal Article
Open access
NANurul Aliah Abdullah
Nurul Aliah Abdullah
FJFairuzeta Ja'afar
Fairuzeta Ja'afar
HYHartini M. Yasin
Hartini M. Yasin
HTHussein Taha
Hussein Taha
MPMark Ihrwell Remollo Petalcorin
Mark Ihrwell Remollo Petalcorin
Anwar UsmanAnwar Usman
Anwar Usman
In this study, the physicochemical, antioxidant, antibacterial properties, and the toxicity of propolis particles produced by stingless bee Heterotrigona itama found in Brunei Darussalam were investigated. Propolis particles of different sizes were extracted from raw propolis using various volume fractions of ethanol in water. Spectroscopic analyses were utilized to characterize the chemical structures, functional groups, as well as absorbance and fluorescence properties. The total antioxidant capacity of propolis particles, which was assessed using DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, was found to increase with volume fraction of ethanol. The maximum antioxidant capacity was as high as 317.65 mg ascorbic acid equivalent per gram of propolis particles. All of the propolis particles showed antibacterial activity against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The diameters of the inhibition zone were either significantly higher or equivalent to those of two standard antibiotics (rifampicin and streptomycin), suggesting strong antibacterial activity. The toxicity studies of propolis particles against Caenorhabditis elegans revealed that they are non-toxic after 24 h exposure. Overall findings suggest that H. itama propolis particles are not only an important source of natural antioxidants that could be beneficial for human health, but they have potentials as antimicrobial against bacteria.

1 November 2015 in Ultrasound in Medicine & Biology
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Journal Article
Closed access
FJFairuzeta Ja'afar
Fairuzeta Ja'afar
CLChee Hau Leow
Chee Hau Leow
VGValeria Garbin
Valeria Garbin
CSCharles A. Sennoga
Charles A. Sennoga
MTMeng-Xing Tang
Meng-Xing Tang
John Michael SeddonJohn Michael Seddon
John Michael Seddon

15 January 2019 in American Journal of Nanomaterials
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Journal Article
Open access
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SZSiti Lailatul N. Zulmajdi
Siti Lailatul N. Zulmajdi
NZNur Izzah I. Zamri
Nur Izzah I. Zamri
AMAbdul Hanif Mahadi
Abdul Hanif Mahadi
MRMohd Yameany H. Rosli
Mohd Yameany H. Rosli
FJFairuzeta Ja'afar
Fairuzeta Ja'afar
Anwar UsmanAnwar Usman
Anwar Usman
This paper describes the photocatalytic degradation of methylene blue (MB) in aqueous solution in the presence of TiO2 nanoparticles (NPs) in different compositions of anatase and rutile phases under UV light irradiation. The different compositions of crystalline phases of TiO2 NPs were synthesized using sol-gel method at the same temperature for various calcination times. The TiO2 NPs were subjected to crystal phase, vibrational, size, and morphological characterizations. The photocatalytic degradation of MB revealed that anatase TiO2 NPs have a superior catalytic activity in the front of rutile phase. This finding further suggested that low charge resistance and low electron-hole recombination probability lead to the acceleration of the OH• formation on the surface of anatase TiO2 NPs.

6 May 2023 in Sustainability
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Md Sumon RezaMd Sumon Reza
Md Sumon Reza
SAShammya Afroze
Shammya Afroze
KKKairat A. Kuterbekov
Kairat A. Kuterbekov
AKAsset Kabyshev
Asset Kabyshev
KBKenzhebatyr Bekmyrza
Kenzhebatyr Bekmyrza
Md Shahinoor IslamMd Shahinoor Islam
Md Shahinoor Islam
Energy demands keep increasing in this modern world as the world population increases, which leads to a reduction in fossil fuels. To resolve these challenges, Pennisetum purpureum, an invasive grass in Brunei Darussalam, was examined as the feedstock for renewable energy through a catalytic pyrolysis process. The activated carbon was applied as the catalyst for a simple and economical solution. The catalytic pyrolysis was executed at 500 °C (the temperature for the highest biofuel yield) for both reactors to produce the highest amount of upgraded biofuels. The biochar produced from the non-catalytic and catalytic pyrolysis processes showed a consistent yield due to stable operating conditions, from which the activated carbon was generated and used as the catalyst in this work. A significant amount of improvement was found in the production of biofuels, especially bio-oil. It was found that for catalysts, the number of phenolic, alcohol, furans, and ketones was increased by reducing the amount of acidic, aldehyde, miscellaneous oxygenated, and nitrogenous composites in bio-oils. The highest amount of phenolic compounds was produced due to a number of functional groups (-C=O and -OH) in activated carbon. The regenerated activated carbons also showed promising outcomes as catalysts for upgrading the bio-oils. The overall performance of synthesized and regenerated activated carbon as a catalyst in catalytic pyrolysis was highly promising for improving the quality and stability of bio-oil.

1 January 2024 in The Scientific World Journal
Verified
Journal Article
Open access
ATAmanina Yusrina Taufik
Amanina Yusrina Taufik
HYHartini Mohd Yasin
Hartini Mohd Yasin
NANorhayati Ahmad
Norhayati Ahmad
MAMasayoshi Arai
Masayoshi Arai
FJFairuzeta Ja'afar
Fairuzeta Ja'afar
This present study aimed to investigate the phytochemical content and antioxidant and antidiabetic activities of Curculigo latifolia leaves (CL) and C. latifolia roots (CR) found in Brunei Darussalam. Phytochemical screening showed that CL and CR extracts contain saponins, tannins, glycosides, and terpenoids. CR showed higher total phenolic content (TPC), but lower total flavonoid content (TFC) when compared to CL. The high TPC in CR contributed to its potent radical scavenging activity (RSA) against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radicals and strong ferric reducing antioxidant power (FRAP). Additionally, CR exerted significant inhibition of ∝‐glucosidase and ∝‐amylase, suggesting a potential link between the chemical compounds and its antioxidant and antidiabetic effects. In the animal study of antihyperglycemic activity, treatment with 250 mg/kg body weight (b.w.) of the CL extract normalised the blood glucose levels and improved body weight gain of alloxan‐induced diabetic rats within 14 weeks. Furthermore, our investigation into the wound‐healing effects of young C. latifolia leaves (YCL) and matured C. latifolia leaves (MCL) showed a significant reduction in wound size on Day 3, 5, and 7 of the experimental study, indicating its wound‐healing potential. Based on our findings, C. latifolia can be consumed as part of a balanced diet due to its antioxidant and antidiabetic properties.