Displaying publications 81 - 100 of 314 in total

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  1. Zakaria Z, Hassan L, Ahmad N, Husin SA, Ali RM, Sharif Z, et al.
    Front Microbiol, 2021;12:652642.
    PMID: 34531832 DOI: 10.3389/fmicb.2021.652642
    Salmonella enterica subspecies enterica serovar Enteritidis is one of the major foodborne zoonotic pathogens globally. It has significantly impacted human health and global trade. In this investigation, whole-genome sequencing was employed to determine the antimicrobial resistance (AMR) pattern of a collection of Salmonella Enteritidis isolated from humans, poultry, and food sources. The study also investigated the virulence genes profile of the isolates as well as the phylogenetic relationships among strains. Illumina NextSeq technology was used to sequence the genome of 82 Salmonella Enteritidis strains isolated over 3 years (2016-2018) in Peninsular Malaysia. The pattern of resistance showed that tetracycline had the highest frequency (37/82, 45.12%), and isolates from food samples showed the highest rate of 9/18 (50.00%), followed by human 17/35 (48.57%) and then poultry 11/29 (37.93%). The second drug with the highest resistance rate is ampicillin with 5/29 (17.24%) for poultry, 4/35 (11.43%) for human, and 0/18 (0.00%) for food isolates respectively. Similarly, a total of 19 antimicrobial resistance (AMR) genes corresponding to the nine drugs used in the disc diffusion assay were evaluated from the whole genome sequence data. The aminoglycoside resistance gene aac(6')-ly was detected in 79 of the 82 isolates (96.34%). While the phylogenetic analysis revealed distinct lineages isolated, the three sources indicating possible cross-contamination. In conclusion, the results showed that the genomic profile of Salmonella Enteritidis isolated from humans, poultry, and food samples share genetic traits, hence the need to institute measures at controlling the continuous spread of these resistant pathogens.
  2. Shaibdat NS, Ahmad N, Azmin S, Ibrahim NM
    Front Neurol, 2023;14:1136858.
    PMID: 36959822 DOI: 10.3389/fneur.2023.1136858
    INTRODUCTION: Patients with Parkinson's disease (PD) are at a higher risk of hospital admissions compared to the general population. We studied the causes and factors associated with admissions among patients with PD over 6 years.

    METHODS: We included all PD admissions between 1 January 2016 and 31 December 2021. Other causes of parkinsonism were excluded. Causes of admissions were divided into PD-related (direct or indirect) or non-PD-related. The type of admission was categorized into emergency or elective.

    RESULTS: We identified 605 hospital admissions (259 patients with PD); 345 (57.0%) were PD-related and 260 (43%) were non-PD-related. Emergency PD admissions contributed to 50.4% of all admissions, most commonly from respiratory infection (23%). PD admissions in comparison to non-PD admissions were associated with worse disease severity (HY ≥ 3; p < 0.001), longer disease duration [8.71 (SD 6.23) vs. 6.60 (SD 5.39) years; p < 0.001], and longer hospital stay [7.70 (SD 5.89) vs. 6.42 (SD 7.63) days; p = 0.020]. Non-PD admissions were associated with more comorbidities (97.3%; p = 0.013). There were 124 (20.5%) complications and 31 deaths (5.1%). A total of 29 deaths were due to respiratory infection and 3 deaths were due to COVID-19 pneumonia. Emergency admission (PD- and non-PD-related; p = 0.001) and respiratory-related causes (p < 0.001) were predictors of unfavorable hospital admission outcomes (death and complications).

    CONCLUSION: Respiratory infection was the leading cause of hospital admission and a significant independent predictor of unfavorable hospital admission outcomes (death and complications). PD-related admissions were associated with disease severity and led to more complications and longer hospital stays. Non-PD-related admissions were associated with comorbidities.

  3. Abubakar M, Ahmad N, Ghafoor A, Latif A, Ahmad I, Atif M, et al.
    Front Pharmacol, 2021;12:640555.
    PMID: 33867989 DOI: 10.3389/fphar.2021.640555
    Background: The current study is conducted with the aim to the fill the gap of information regarding treatment outcomes and variables associated with unsuccessful outcome among XDR-TB patients from Pakistan. Methods: A total of 404 culture confirmed XDR-TB patients who received treatment between 1st May 2010 and June 30, 2017 at 27 treatment centers all over Pakistan were retrospectively followed until their treatment outcomes were reported. A p-value <0.05 reflected a statistical significant association. Results: The patients had a mean age 32.9 ± 14.1 years. The overall treatment success rate was 40.6% (95% confidence interval [CI]:35.80-45.60%). A total of 155 (38.4%) patients were declared cured, 9 (2.2%) completed treatment, 149 (36.9%) died, 60 (14.9%) failed treatment and 31 (7.7%) were lost to follow up (LTFU). The results of the multivariate binary logistic regression analysis revealed that the patients' age of >60 years (OR = 4.69, 95%CI:1.57-15.57) and receiving high dose isoniazid (OR = 2.36, 95%CI:1.14-4.85) had statistically significant positive association with death, whereas baseline body weight >40 kg (OR = 0.43, 95%CI:0.25-0.73) and sputum culture conversion in the initial two months of treatment (OR = 0.33, 95%CI:0.19-0.58) had statistically significant negative association with death. Moreover, male gender had statistically significant positive association (OR = 1.92, 95%CI:1.04-3.54) with LTFU. Conclusion: The treatment success rate (40.6%) of XDR-TB patients in Pakistan was poor. Providing special attention and enhanced clinical management to patients with identified risk factors for death and LTFU in the current cohort may improve the treatment outcomes.
  4. Yusli NANM, Roslan S, Zaremohzzabieh Z, Ghiami Z, Ahmad N
    Front Psychol, 2021;12:646329.
    PMID: 34489779 DOI: 10.3389/fpsyg.2021.646329
    Many university students experience high levels of study-related fatigue, hence, necessitating opportunities for restoration. They could potentially benefit from campus-based physical activities that provide them with effective restoration breaks and allow them to return to their studies cognitively refreshed. Thus, a cross-sectional study was conducted to assess the association between perceived restorativeness among postgraduates and their psychological well-being by using the four constructs of Kaplan's attention restoration theory (ART): fascination, being away, extent, and compatibility. In this study, nature view windows were also used as a moderator. Malaysian postgraduate students [n = 192; 94 females; age in years (M = 30.64, SD = 2.73)] completed the Ryff's scale of psychological wellbeing (PWB) and perceived restorativeness scale for activity (PRAS). This study used the partial least squares-structural equation model (PLS-SEM) to examine these relationships. The results demonstrate that three ART constructs, namely, being away, fascination, and compatibility, are significant predictors of psychological well-being across the sample size. Furthermore, for participants who reside in university dormitories, windows that overlook nature can enhance the relationship of being away, compatibility, and fascination to psychological well-being, compared with those with less natural views. Thus, this study confirmed the moderating effect of nature view windows and provided insight into the ART constructs that facilitate and enhance restorative experiences. By strengthening ART with additional factors, this study has also contributed toward the improvement of the psychological well-being of university students.
  5. Ishaq R, Shoaib M, Baloch NS, Sadiq A, Raziq A, Huma ZE, et al.
    Front Public Health, 2021;9:801035.
    PMID: 35111720 DOI: 10.3389/fpubh.2021.801035
    Background: Quality of Life (QoL) and its determinants are significant in all stages of life, including pregnancy. The physical and emotional changes during pregnancy affect the QoL of pregnant women, affecting both maternal and infant health. Hence, assessing the QoL of pregnant women is gaining interest in literature. We, therefore, aimed to describe the QoL of pregnant women during physiological pregnancy and to identify its associated predictors in women attending a public healthcare institute of Quetta city, Pakistan.

    Methods: A cross-sectional study was conducted at the Obstetrics and Gynecology Department of Sandeman Provincial Hospital Quetta city, Pakistan. The respondents were asked to answer the Urdu (lingua franca of Pakistan) version of the Quality of Life Questionnaire for Physiological Pregnancy. Data were coded and analyzed by SPPS v 21. The Kolmogorov-Smirnov test was used to establish normality of the data and non-parametric tests were used accordingly. Quality of Life was assessed as proposed by the developers. The Chi-square test was used to identify significant associations and linear regression was used to identify the predictors of QoL. For all analyses, p < 0.05 was taken significantly.

    Results: Four hundred and three pregnant women participated in the study with a response rate of 98%. The mean QoL score was 19.85 ± 4.89 indicating very good QoL in the current cohort. The Chi-Square analysis reported a significant association between age, education, occupation, income, marital status, and trimester. Education was reported as a positive predictor for QoL (p = 0.006, β = 2.157). On the other hand, trimester was reported as a negative predictor of QoL (p = 0.013, β = -1.123).

    Conclusion: Improving the QoL among pregnant women requires better identification of their difficulties and guidance. The current study highlighted educational status and trimester as the predictors of QoL in pregnant women. Health care professionals and policymakers should consider the identified factors while designing therapeutic plans and interventions for pregnant women.

  6. Ahmad N, Khan SA, Majid HA, Ali R, Ullah R, Bari A, et al.
    Front Vet Sci, 2024;11:1380203.
    PMID: 38655530 DOI: 10.3389/fvets.2024.1380203
    INTRODUCTION: Haemonchus contortus (H. contortus) is a blood-feeding nematode causing infectious disease haemonchosis in small ruminants of tropical and subtropical regions around the world. This study aimed to explore the prevalence and phylogeny of H. contortus in small ruminants using the internal transcribed spacer-2 (ITS-2) gene. In addition, a comprehensive review of the available literature on the status of H. contortus in Pakistan was conducted.

    METHODS: Fecal samples were collected from sheep and goats (n = 180). Microscopically positive samples were subjected to DNA extraction followed by PCR using species-specific primers.

    RESULTS: The overall prevalence of H. contortus was 25.55% in small ruminants. The prevalence of H. contortus was significantly associated with months and area. The highest occurrence of haemonchosis was documented in July (38.70%), whereas the lowest occurred in December (11.11%), with significant difference. The prevalence was highest in the Ghamkol camp (29.4%) and lowest in the arid zone of the Small Ruminant Research Institute (17.5%) (p = 0.01). The results of the systematic review revealed the highest prevalence of haemonchosis (34.4%) in Khyber Pakhtunkhwa (p = 0.001).

    DISCUSSION: Phylogenetic analysis revealed a close relationship between H. contortus and isolates from Asia (China, India, Iran, Bangladesh, Malaysia, and Mongolia) and European countries (Italy and the United Kingdom). It has been concluded that H. contortus is prevalent in small ruminants of Kohat district and all over Pakistan, which could be a potential threat to food-producing animals, farmers, dairy, and the meat industry. Phylogenetic analysis indicates that H. contortus isolates share close phylogenetic relationships with species from Asia and Europe.

  7. Arushothy R, Ahmad N, Amran F, Hashim R, Samsuddin N, Che Azih CR
    Genome Announc, 2018 Apr 19;6(16).
    PMID: 29674530 DOI: 10.1128/genomeA.00167-18
    After the introduction of the pneumococcal conjugate vaccine in Malaysia in recent years, the emergence of nonvaccine serotypes is of concern, particularly the antibiotic-resistant strains, with an increase specifically in serotype 15A. Here, we report the draft genome sequence of Streptococcus pneumoniae strain SS40_16, isolated from the blood sample of a 19-month-old female in 2016. SS40_16 is a multidrug-resistant strain with resistance to penicillin (MIC, ≥2 µg/ml), tetracycline, and trimethoprim-sulfamethoxazole. The strain belongs to serotype 15A and sequence type 1591 (ST1591).
  8. Mohd Tap R, Kamarudin NA, Ginsapu SJ, Ahmed Bakri AR, Ahmad N, Amran F, et al.
    Genome Announc, 2018 Apr 05;6(14).
    PMID: 29622608 DOI: 10.1128/genomeA.00166-18
    Candida pseudohaemulonii is phylogenetically close to the C. haemulonii complex and exhibits resistance to amphotericin B and azole agents. We report here the draft genome sequence of C. pseudohaemulonii UZ153_17 isolated from the blood culture of a neutropenic patient. The draft genome is 3,532,003,666 bp in length, with 579,838 reads, 130 contigs, and a G+C content of 47.15%.
  9. Amran F, Mohd Khalid MK, Mohamad S, Mat Ripen A, Ahmad N, Goris MG, et al.
    Genome Announc, 2016;4(5).
    PMID: 27609924 DOI: 10.1128/genomeA.00956-16
    Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia.
  10. Mohamed Zahidi J, Ahmad N, Tay BY, Hashim R, Khoo E, Ahmad N, et al.
    Genome Announc, 2017 Aug 03;5(31).
    PMID: 28774972 DOI: 10.1128/genomeA.00689-17
    Human brucellosis is a neglected zoonotic disease and has widespread geographical distribution. Brucella melitensis has caused outbreaks and sporadic cases in Malaysia. Here, we present the whole-genome sequences of four B. melitensis strains isolated from brucellosis patients in Malaysia.
  11. Ahmad N, Hii SY, Mohd Khalid MK, Abd Wahab MA, Hashim R, Tang SN, et al.
    Genome Announc, 2017 Mar 02;5(9).
    PMID: 28254972 DOI: 10.1128/genomeA.01670-16
    Corynebacterium diphtheriae has caused multiple isolated diphtheria cases in Malaysia over the years. Here, we report the first draft genome sequences of 15 Malaysia C. diphtheriae clinical isolates collected from the years 1981 to 2016.
  12. Ahmad N, Zakaria WR, Mohamed R
    Helicobacter, 2011 Feb;16(1):47-51.
    PMID: 21241412 DOI: 10.1111/j.1523-5378.2010.00816.x
    The prevalence of antibiotic resistance varies in geographic areas. The information on the antibiotic susceptibility patterns of Helicobacter pylori (H. pylori) in our local setting is therefore relevant as a guide for the treatment options.
  13. Baharom M, Ahmad N, Hod R, Ja'afar MH, Arsad FS, Tangang F, et al.
    Heliyon, 2024 Jan 15;10(1):e23473.
    PMID: 38173528 DOI: 10.1016/j.heliyon.2023.e23473
    BACKGROUND: Leptospirosis is a neglected emerging zoonotic disease with a profound public health impact worldwide with higher burden of disease in resource-poor countries. The environmental and occupational exposures contribute to human and animal transmission, but the interaction was less explored. A deeper understanding of the critical environmental and occupational drivers in different contexts will provide useful information for disease control and prevention measures.

    OBJECTIVE: This review aimed to summarize the potential environmental and occupational risk factors associated with leptospirosis infection.

    METHODS: Four databases (Scopus, Web of Science, Ovid MEDLINE, EBSCOhost) were searched for articles published from 2012 to 2021. Eligible articles were assessed using a checklist for assessing the quality of the studies. The quality of the articles was assessed based on the laboratory diagnosis approach and statistical analysis method.

    RESULTS: A total of 32 studies were included in this systematic review. Water-related risk factors such as natural water as the primary water source (AOR 1.8-18.28), water-related recreational activities (AOR 2.36-10.45), flood exposure (AOR 1.54-6.04), contact with mud (AOR 1.57-4.58) and stagnant water (AOR 2.79-6.42) were associated with increased risk of leptospirosis. Infrastructural deficiencies such as un-plastered house walls and thatched houses presented a higher risk (AOR 2.71-5.17). Living in low-lying areas (AOR 1.58-3.74), on clay loam soil (OR 2.72), agricultural land (OR 2.09), and near rubber tree plantations (AOR 11.65) is associated with higher risk of leptospirosis. Contact with rats (AOR 1.4-3.5), livestock (AOR 1.3-10.4), and pigs (AOR 1.54-7.9) is associated with an increased risk of leptospirosis. Outdoor workers (AOR 1.95-3.95) and slaughterhouse workers (AOR 5.1-7.5) have higher risk of leptospirosis.

    CONCLUSION: The environmental and occupational components related to water, infrastructure, landscape, agriculture, and exposed animals play an essential role in leptospirosis transmission. The magnitude of those risk factors differs with geographical region, climate factor, urbanization and population growth, and the country's socioeconomic status.

  14. Ab Hamid N, Mohd Noor SN, Susubi J, Isa NR, Md Rodzay R, Bachtiar Effendi AM, et al.
    Heliyon, 2020 Jan;6(1):e03230.
    PMID: 31993521 DOI: 10.1016/j.heliyon.2020.e03230
    In recent decades, dengue incidence has trended upward worldwide causing urgent needs for new or modified vector control methods. We modified the existing indoor residual spraying (IRS) method by applying insecticide on the outer walls of building structures in an outdoor residual spraying (ORS) study. A semi-field study was conducted to investigate the bio-efficacy of two different deltamethrin formulations: K-Othrine® Polyzone, new polymer-enhanced deltamethrin formulated as a suspension concentrate (SC-PE), and K-Othrine® WG 250, traditional deltamethrin formulated as water dispersible granule (WG). The residual bio-efficacy of deltamethrin SC-PE was compared to deltamethrin WG on finished cement surfaces applied to the outer walls at the Institute for Medical Research (IMR), Malaysia. Standard WHO cone wall bioassays were adapted to evaluate the effective duration of action of these deltamethrin formulations against susceptible laboratory-reared and wild, free-flying Aedes aegypti and Ae. albopictus. Analyses of bioassay results showed that deltamethrin SC-PE 30 mg/m2 has improved longevity in comparison to deltamethrin WG 30 mg/m2. Deltamethrin SC-PE 30 mg/m2 was effective until week 17 (producing > 80% mortality), surpassing deltamethrin WG 30 mg/m2 which only lasted until week 10. This was supported by post-hoc test analyses which demonstrated that deltamethrin SC-PE 30 mg/m2 produced the highest mean of mortality in laboratory-reared Aedes species and the wild Ae. albopictus. However, the effective duration of action of deltamethrin SC-PE (17 weeks) was less than the recommended period by WHO (6 months) but was reasonable given that the spraying was undertaken outdoor. This preliminary data could be of use for the deployment of locally adapted ORS operation in controlling dengue.
  15. Shafie AA, Ahmad N, Naidoo J, Foo CY, Wong C, Pugh S, et al.
    Hum Vaccin Immunother, 2020 07 02;16(7):1719-1727.
    PMID: 31951782 DOI: 10.1080/21645515.2019.1701911
    Pneumococcal disease is a potentially fatal bacterial infection that is vaccine-preventable. Malaysia has yet to adopt a pneumococcal conjugate vaccine (PCV) into its national immunization program (NIP). In 2016, pneumonia was the 3rd leading cause of death in children under five in Malaysia, accounting for 3.8% of under-five deaths. Introducing a pneumococcal conjugate vaccine (PCV) is an effective strategy to reduce the disease burden. This study used a decision-analytic model to assess the potential impacts of introducing the available PCVs (13-valent and 10-valent) in Malaysia. Epidemiological and costs inputs were sourced from published literature. For each vaccination program, health outcomes and associated healthcare costs were estimated. The scenarios of initiating PCV13 vs. PCV10 and the status quo (no pneumococcal vaccine) were compared. Serotype trends of Finland and the U.K. were used to model the clinical impacts of PCV10 and PCV13 respectively. The base-case analysis used a societal perspective over a 5-year time horizon. Compared with PCV10, PCV13 was projected to avert an additional 190,628 cases of pneumococcal disease and 1126 cases of death. The acquisition of PCV13 was estimated to cost an incremental US$89,904,777, offset by a cost reduction of -US$250,219,914 on pneumococcal disease-related medical care and lost productivity. PCV13 demonstrated a higher cost-saving potential over PCV10. Compared with no vaccination, PCV13 was estimated as cost-saving. Results were robust across a series of sensitivity analyses. The introduction of PCV13 in a NIP was estimated to reduce a significant burden of disease and to be a cost-saving for the Malaysian health system.
  16. Tan S, Ismail MAB, Daud TIM, Hod R, Ahmad N
    Indian J Psychiatry, 2023 Sep;65(9):934-940.
    PMID: 37841542 DOI: 10.4103/indianjpsychiatry.indianjpsychiatry_240_23
    INTRODUCTION: Despite the increasing number of mental health professionals in Malaysia, many have yet to receive adequate treatment for common mental illnesses such as depression and anxiety. Coupled with the increasing number of mobile phone users globally, smartphone-based intervention can be a promising mental health intervention. Thus, this study aims to investigate the efficacy of using a smartphone-based mental health application in addition to treatment-as-usual (TAU) in outpatients with depressive and/or anxiety symptoms.

    METHODS: Psychiatric outpatients that fulfill the selection criteria were recruited and randomized into two groups, the intervention group (n = 24) and the control group (n = 24). Those in the intervention group received MoodMission in addition to TAU, while those in the control group received TAU. Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) scores were assessed at baseline and after four weeks.

    RESULTS: A total of 48 participants were recruited, randomized, and completed the study. Baseline characteristics for both groups were comparable. There is no significant mean difference between-group comparison of PHQ-9 (1.31, 95% CI -1.35, 3.98) and GAD-7 (0.02, 95% CI -2.01, 2.05) scores at four weeks. However, for the intervention group, there was a significant improvement in the PHQ-9 score at four weeks [mean difference 2.58 (95% CI 1.16, 4.01), P = 0.001)].

    CONCLUSION: This study showed no significant improvement in anxiety symptoms after four weeks. Use of smartphone-based mental health applications led to significant reduction of depressive symptoms.

  17. Mohd-Zain Z, Kamsani NH, Ahmad N, Clarke SC
    Infect Genet Evol, 2015 Dec;36:240-3.
    PMID: 26394107 DOI: 10.1016/j.meegid.2015.09.017
    The epidemiology of non-typeable Haemophilus influenzae (NTHi) remains poorly understood. We therefore sought to determine the genetic relationship of 25 NTHi isolated from various states in Malaysia using multilocus sequence typing (MLST). The majority of isolates were obtained from sputum. There were 24 novel sequence types (STs). Eight isolates were single-locus variants, the remainder being singletons. Clustering was not based on clinical site of isolation or geographical origin. Despite the limited number of isolates examined in this study, we demonstrate that NTHi isolates in Malaysia are diverse and warrant further investigation.
  18. Mhd Abd Kader, K. A., Ab. Aziz, N., Aziz, A., Talib, A. T., Ahmad, N. H., Tan, C. P., et al.
    MyJurnal
    Pink Guava Puree (PGP) factory produces tons of residues from its unit operation [refiner (R),
    siever (S), and decanter (D)]. These residues represent a waste of nutrients and can contribute
    to environmental problem. However, it can benefit related industries if the properties of the
    residues are known. Thus, this research aims to determine the compositions of the residues
    from PGP processing factory in order to evaluate possible value-added by-product and energy
    sources. The residues from each unit operation were being tested for proximate composition,
    dietary fibre components, pH value, emulsifying activity (EA) and emulsifying stability (ES),
    carbon-to-nitrogen (C/N) ratio, and sugar analysis. The sugar content was analysed using High
    Performance Liquid Chromatography (HPLC-RI detector). Results showed that the residues
    have good composition of carbohydrate (11.82–12.18%), and thus potential as carbon source
    and can be a good substrate for fermentation. These residues may also benefit the food industry
    as a good source of dietary fibre (18.63–29.86%). The pH value for these PGP residues is 4;
    thus they were considered as acidic food by-product. The low pH value also contributed to the
    low EA and ES value other than the low content of protein in the sample. C/N ratio for PGP
    residue from R (46:1) is the lowest compared to the C/N ratio from S (84:1) and D (115:1). The
    amount of sugars detected in the PGP residues in descending order were fructose > glucose >
    sucrose.
  19. Boon, Y. T., Naim, M. N., Zakaria, R., Abu Bakar, N. F., Ahmad, N.
    MyJurnal
    A study on the feasibility of using gel electrophoresis technique in grading the agarwood oil
    quality was investigated. Prior to electrophoresis, the emulsified agarwood oil droplets were
    screened by a diffuse layer of ions that have equal absolute charge to that of the droplets surface
    charge in aqueous phase. The condition was obtained by varying the concentrations of nonionic
    surfactant; Tween 80 until the critical aggregation concentration (CAC) value of 0.0167%
    (v/v) was achieved. The prepared droplets suspended in the aqueous within nano-metre size and
    had ability to migrate through the agarose gel with its own specific electrophoretic mobility.
    However, due to the limitation of gel pore size, only large oil droplets (>200 nm) indicated
    visible bands. Overall, a novel work for grading the emulsified agarwood oil droplet with its
    own electrical properties was feasible.
  20. Zainal Abidin, N.F., Yusoff, A., Ahmad, N.
    MyJurnal
    Octenyl succinic anhydride (OSA) modified sago starch was prepared in order to improve the emulsification properties of native starch. In the present study, the major factors affecting esterification were investigated with respect to OSA concentration, pH and reaction time using response surface methodology (RSM) based on central composite rotatable design (CCRD) to obtain the highest value of degree of substitution (DS). Results shown that the optimum conditions for OSA concentration, pH and reaction time were 5.00%, pH 7.20 and 9.65 h, respectively. At optimum condition, the esterification of sago starch with OSA resulted in DS value of 0.0120. The DS increased linearly with the increase in amount of OSA, whilst pH and reaction time show a curvature trend on the value of DS. The value of DS was found to be significantly affected by all the three variables. The experimental values under optimum condition were in good consistent with the predicted values (0.0131), which suggested that the optimisation by RSM is more efficient process than conventional optimisation.
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