Now showing 1 - 10 of 11
  • Publication
    Atomisation and vacuum drying studies on Malaysian honey encapsulation
    (The Korean Society of Food Preservation, 2023)
    Nurul Aisyah Rosli
    ;
    ; ;
    Malaysian honey is rich in nutrients and bioactive compounds, which can be a healthy alternative to refined sugar in food production. However, liquid honey’s viscous and sticky nature makes it unpreferable in industrial handling. This study, an atomization system coupled with vacuum drying to produce honey powders to overcome the problem. Three types of Malaysian honey, namely Acacia, Gelam, and Tualang, were encapsulated in Ca-alginate gel beads using the atomization system. The density viscosity, and surface tension of the honey-alginate solutions were measured, and the concentration of honey and alginate influenced the physical properties of the solutions. Honey-encapsulated gel beads in the size range of 2.16-2.92 mm were produced using the atomization system with the air-liquid mass flow rate ratios of 0.22-0.31, Weber number (We) of 112-545, and Ohnersorges number (Oh) of 0.35-10.46. Gel bead diameter can be predicted using a simple mathematical model. After vacuum drying, the honey gel powder produced was in the size range of 1.50-1.79 mm. Results showed that honey gel powders with good encapsulation efficiency and high honey loading could be produced using the atomization system and vacuum drying.
  • Publication
    Complex Impedance and Modulus Analysis on Porous and Non-Porous Scaffold Composites Due to Effect of Hydroxyapatite/Starch Proportion
    This study aims to investigate the electric responses (complex modulus and complex impedance analysis) of hydroxyapatite/starch bone scaffold as a function of hydroxyapatite/starch proportion and the microstructural features. Hence, the non-porous and porous hydroxyapatite/starch composites were fabricated with various hydroxyapatite/starch proportions (70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 10/90 wt/wt%). Microstructural analysis of the porous hydroxyapatite/starch composites was carried out by using scanning electron microscopy. It shows that the formation of hierarchical porous microstructures with high porosity is more significant at a high starch proportion. The complex modulus and complex impedance analysis were conducted to investigate the electrical conduction mechanism of the hydroxyapatite/starch composites via dielectric spectroscopy within a frequency range from 5 MHz to 12 GHz. The electrical responses of the hydroxyapatite/starch composites are highly dependent on the frequency, material proportion, and microstructures. High starch proportion and highly porous hierarchical microstructures enhance the electrical responses of the hydroxyapatite/starch composite. The material proportion and microstructure features of the hydroxyapatite/starch composites can be indirectly reflected by the simulated electrical parameters of the equivalent electrical circuit models.
      4
  • Publication
    Antimicrobial activity and phytochemical analysis of Azadirachta Indica (neem) and Clinacanthus Nutans (snake grass) leaves extract
    (AIP Publishing, 2023) ;
    Siti Zulaika Zaini
    ;
    Nurul Jannah Jamaluddin
    ;
    ;
    Shaida Fariza Sulaiman
    Azadirachta indica (A. indica) and Clinacanthus nutans (C. nutans) is a traditional medicinal plant with a great medical impact on bacteria inflammation. They are few studies for the phytochemical and antimicrobial were conducted for both types of plants. Phytochemical analysis was performed using classical colorimetric methods, which is the folin-Ciocalteu method and aluminum chloride precipitation were employed for quantitative of total phenolic content (TPC) and total flavonoid content (TFC). Meanwhile, antioxidant activity was estimated by DPPH scavenging value. Antimicrobial activity was determined by using the agar well diffusion method against Escherichia coli (E. coli) and Staphylococcus aureus (Staphy. aureus). The methanol crude extract of A. indica and C. nutans showed low content of phenolic, 1.65 mg GAE/g, 0.18 mg GAE/g; flavonoid content is 43.56 mg QE/g and 26.07 mg QE/g respectively for both extracts. Meanwhile, the percentage of scavenging activity is 87.13% and 34.90% for A. indica and C. nutans. Regarding the antimicrobial activity, the A. indica extract inhibits the growth of target bacteria with a minimum inhibitory concentration of 31.25 mg/ml for both strains and almost no inhibitory concentration for C. nutans. Hence, aim this study is to determine two local plant varieties as a source of antimicrobial agents by used soxhlet extraction method.
      11  1
  • Publication
    Radar plot analysis of Helicobacter pylori detection in North Peninsular Malaysia
    (Intisari Sains Medis (Indonesia), 2023) ;
    Yahya Mat Arip
    ;
    Uyub Abdul Manaf
    ;
    Marni Azera Markon
    Introduction: Helicobacter pylori (H. pylori) infection is one serious disease that could result in complications such as gastritis, peptic ulcer and gastric cancer. Both invasive and non-invasive methods have been used to detect the infection, however the best detection depends on the clinical setting. One way to determine this is by graphical radar plot analysis, as it provides practical and useful data for many clinical aspects. The aim of this study was to investigate the prevalence rate of H. pylori ureA genotypes infection with a graphical technique. Method: We conducted a cross-sectional study in which data was collected from patients with infection symptoms in north peninsular Malaysia. All eligible subjects were required to perform a simple clinical procedure to provide their cell and saliva samples. Subjects were also examined by the medical staff based on their symptoms. Detection of H.pylori in the samples were conducted with three different detection methods such as culture, biopsy, saliva and the combination of thee three methods. Results: Biopsies were cultured and revealed 19.2% (48/250) of the patients had H. pylori infection. However, when PCR and culture were combined, the prevalence of H. pylori infection jumped by three times to 59.6% (149/250), indicating that PCR on biopsies and saliva was more sensitive. Males who were not Malay and Malay males in the age range of 41 to 60 were found to have significantly different rates of H. pylori infection (p 0.05), according to age group. According to ethnicity, 49.5% (28/58) Malay men were infected compared to 68.1% (62/91) non-Malaysia men (p0.05), while there was no difference between 64.2% (34/53) non-Malaysia women and 51.1% (23/45) Malay women. Conclusion: This study found that saliva method is accurate for the identification of H. pylori. This approach has several advantages that could be helpful to patients worldwide, thus diagnosis and treatment can be done earlier to prevent complications.
      23  1
  • Publication
    Lumped-element circuit modeling for composite scaffold with nano-hydroxyapatite and wangi rice starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      21  1
  • Publication
    Lumped-Element Circuit Modeling for Composite Scaffold with Nano-Hydroxyapatite and Wangi Rice Starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      2  31
  • Publication
    Lumped-element circuit modeling for composite scaffold with Nano-Hydroxyapatite and wangi rice starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      15  1
  • Publication
    Mineral composition, crystallinity and dielectric evaluation of Bamboo Salt, Himalaya Salt, and Ba’kelalan salt content
    ( 2024) ; ; ; ;
    Ong Hong Liang
    ;
    Tan Xiao Jian
    ;
    Lee Kim Yee
    ;
    You Kok Yeow
    ;
    Emma Ziezie Mohd Tarmizi
    ;
    Mohd Riza Mohd Roslan
    ;
    Siti Aishah Baharuddin
      33  1
  • Publication
    Complex impedance and modulus analysis on porous and non-porous scaffold composites due to effect of Hydroxyapatite/starch proportion
    This study aims to investigate the electric responses (complex modulus and complex impedance analysis) of hydroxyapatite/starch bone scaffold as a function of hydroxyapatite/starch proportion and the microstructural features. Hence, the non-porous and porous hydroxyapatite/starch composites were fabricated with various hydroxyapatite/starch proportions (70/30, 60/40, 50/50, 40/60, 30/70, 20/80, and 10/90 wt/wt%). Microstructural analysis of the porous hydroxyapatite/starch composites was carried out by using scanning electron microscopy. It shows that the formation of hierarchical porous microstructures with high porosity is more significant at a high starch proportion. The complex modulus and complex impedance analysis were conducted to investigate the electrical conduction mechanism of the hydroxyapatite/starch composites via dielectric spectroscopy within a frequency range from 5 MHz to 12 GHz. The electrical responses of the hydroxyapatite/starch composites are highly dependent on the frequency, material proportion, and microstructures. High starch proportion and highly porous hierarchical microstructures enhance the electrical responses of the hydroxyapatite/starch composite. The material proportion and microstructure features of the hydroxyapatite/starch composites can be indirectly reflected by the simulated electrical parameters of the equivalent electrical circuit models.
      2  8
  • Publication
    Lumped-element circuit modeling for composite Scaffold with Nano-Hydroxyapatite and Wangi Rice Starch
    Mechanistic studies of the interaction of electromagnetic (EM) fields with biomaterials has motivated a growing need for accurate models to describe the EM behavior of biomaterials exposed to these fields. In this paper, biodegradable bone scaffolds were fabricated using Wangi rice starch and nano-hydroxyapatite (nHA). The effects of porosity and composition on the fabricated scaffold were discussed via electrical impedance spectroscopy analysis. The fabricated scaffold was subjected to an electromagnetic field within the X-band and Ku-band (microwave spectrum) during impedance/dielectric measurement. The impedance spectra were analyzed with lumped-element models. The impedance spectra of the scaffold can be embodied in equivalent circuit models composed of passive components of the circuit, i.e., resistors, inductors and capacitors. It represents the morphological, structural and chemical characteristics of the bone scaffold. The developed models describe the impedance characteristics of plant tissue. In this study, it was found that the ε′ and ε″ of scaffold composites exhibited up and down trends over frequencies for both X-band and Ku-band. The circuit models presented the lowest mean percentage errors of Z′ and Z″, i.e., 3.60% and 13.80%, respectively.
      1  17