Displaying publications 41 - 60 of 160 in total

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  1. Potential authentication of various meat-based products using simple and efficient DNA extraction method
    Khairil Mokhtar NF, El Sheikha AF, Azmi NI, Mustafa S
    J Sci Food Agric, 2020 Mar 15;100(4):1687-1693.
    PMID: 31803942 DOI: 10.1002/jsfa.10183
    BACKGROUND: The growth of halal food consumption worldwide has resulted in an increase in the request for halal authentication. DNA-based detection using powerful real-time polymerase chain reaction (PCR) technique has been shown to be highly specific and sensitive authentication tool. The efficient DNA extraction method in terms of quality and quantity is a backbone step to obtain successful real-time PCR assays. In this study, different DNA extraction methods using three lysis buffers were evaluated and developed to recommend a much more efficient method as well as achieve a successful detection using real-time PCR.

    RESULTS: The lysis buffer 2 (LB2) has been shown to be the best lysis buffer for DNA extraction from both raw and processed meat samples comparing to other lysis buffers tested. Hence, the LB2 has been found to be ideal to detect meat and porcine DNAs by real-time PCR using pairs of porcine specific primers and universal primers which amplified at 119 bp fragment and 93 bp fragment, respectively. This assay allows detection as low as 0.0001 ng of DNA. Higher efficiency and sensitivity of real-time PCR via a simplified DNA extraction method using LB2 have been observed, as well as a reproducible and high correlation coefficient (R2  = 0.9979) based on the regression analysis of the standard curve have been obtained.

    CONCLUSION: This study has established a fast, simple, inexpensive and efficient DNA extraction method that is feasible for raw and processed meat products. This extraction technique allows an accurate DNA detection by real-time PCR and can also be implemented to assist the halal authentication of various meat-based products available in the market. © 2019 Society of Chemical Industry.

    Matched MeSH terms: Food Contamination/analysis*
  2. Fulltext Microbiological Safety of Street-Vended Beverages in Chow Kit, Kuala Lumpur
    Mohd Nawawee NS, Abu Bakar NF, Zulfakar SS
    Int J Environ Res Public Health, 2019 11 13;16(22).
    PMID: 31766289 DOI: 10.3390/ijerph16224463
    Improper handling, poor hygienic practices, and lack of environmental control affect the safety of street-vended beverages. The objective of this study is to determine the bacterial contamination level of three types of beverages (cordial-based drinks, milk-based drinks, fruit juices) sold by street vendors at Chow Kit, Kuala Lumpur. A total of 31 samples of beverages were analyzed to determine total viable count (TVC), total coliform, Escherichia coli, and Staphylococcus aureus counts via the standard plate count method. The results showed that only 9.7% of the total samples were not contaminated with the tested microorganisms. All milk-based drink samples were positive for TVC and also had the highest average bacterial counts at 5.30 ± 1.11 log Colony Forming Unit/mL (CFU/mL). About 71% of the samples were contaminated with total coliform with the average readings ranging between 4.30 and 4.75 log CFU/mL, whereas 58.1% of the samples were positive with S. aureus, with fruit juices having the highest average reading (3.42 ± 1.15 log CFU/mL). Only one sample (milk-based drink) was E. coli positive. This study showed that the microbiological safety level of street-vended beverages in Chow Kit, Kuala Lumpur was average and needs to be improved. Provision of food safety education and adequate sanitary facilities at vending sites are suggested to increase the safety of food products.
    Matched MeSH terms: Food Contamination/analysis*
  3. Rapid detection of porcine DNA in processed food samples using a streamlined DNA extraction method combined with the SYBR Green real-time PCR assay
    Tan LL, Ahmed SA, Ng SK, Citartan M, Raabe CA, Rozhdestvensky TS, et al.
    Food Chem, 2020 Mar 30;309:125654.
    PMID: 31678669 DOI: 10.1016/j.foodchem.2019.125654
    A specialized DNA extraction method and a SYBR Green quantitative polymerase chain reaction (SyG-qPCR) assay were combined to generate a ready-to-use kit for rapid detection of porcine admixtures in processed meat products. Our qPCR assay utilized repetitive LINE-1 elements specific to the genome of Sus scrofa domesticus (pig) as a target and incorporated internal controls. We improved the genomic DNA extraction method, and reduced extraction times to the minimum. The method was validated for specificity, sensitivity (0.001% w/w) and robustness, and values were compared with those of a commercially available kit. We also tested our method using 121 processed food products and consistently detected amplification only in samples containing pork. Due to its efficiency and cost-effectiveness, our method represents a valuable new method for detecting food adulteration with pork that is superior to existing quality control approaches.
    Matched MeSH terms: Food Contamination/analysis*
  4. A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles
    Che Sulaiman IS, Chieng BW, Osman MJ, Ong KK, Rashid JIA, Wan Yunus WMZ, et al.
    Mikrochim Acta, 2020 01 15;187(2):131.
    PMID: 31940088 DOI: 10.1007/s00604-019-3893-8
    This review (with 99 refs.) summarizes the progress that has been made in colorimetric (i.e. spectrophotometric) determination of organophosphate pesticides (OPPs) using gold and silver nanoparticles (NPs). Following an introduction into the field, a first large section covers the types and functions of organophosphate pesticides. Methods for colorimetric (spectrophotometric) measurements including RGB techniques are discussed next. A further section covers the characteristic features of gold and silver-based NPs. Syntheses and modifications of metal NPs are covered in section 5. This is followed by overviews on enzyme inhibition-based assays, aptamer-based assays and chemical (non-enzymatic) assays, and a discussion of specific features of colorimetric assays. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section addresses current challenges and discusses potential future trends and opportunities. Graphical abstractSchematic representation of organophosphate pesticide determinations based on aggregation of nanoparticles (particular silver or gold nanoparticles). This leads to a color change which can be determined visually and monitored by a red shift in the absorption spectrum.
    Matched MeSH terms: Food Contamination/analysis
  5. Electrochemical determination of zearalenone using a label-free competitive aptasensor
    Azri FA, Eissa S, Zourob M, Chinnappan R, Sukor R, Yusof NA, et al.
    Mikrochim Acta, 2020 04 12;187(5):266.
    PMID: 32279134 DOI: 10.1007/s00604-020-4218-7
    An electrochemical aptasensor is described for determination of the phytohormone of zearalenone (ZEA). The gold electrode was modified with ZEA via covalent attachment using cysteamine-hydrochloride and 1,4-phenylene diisocyanate linker. A truncated ZEA aptamer with a dissociation constant of 13.4 ± 2.1 nM was used in an aptasensor. The electrochemical property was investigated using square wave voltammetry for monitoring the change in the electron transfer using the ferro/ferricyanide system as redox probe. Under optimal experimental conditions, the response was best measured at a potential of 0.20 V (vs. Ag/AgCl). The signals depended on the competitive mechanism between the immobilised ZEA and free ZEA for the aptamer binding site. The aptasensor works in the range 0.01 to 1000 ng·mL-1 ZEA concentration, with a detection limit of 0.017 ng·mL-1. High degree of cross-reactivity with the other analogues of ZEA was observed, whereas none towards other mycotoxins. The aptasensor was further applied for the determination of ZEA in the extract of maize grain and showed good recovery percentages between 87 and 110%. Graphical abstract Schematic representation of the electrochemical determination of zearalenone based on indirect competitive assay. Step a Immobilisation of ZEA on the surface of gold electrode via covalent attachment, b competition for the ZEA aptamer binding site between immobilised and free ZEA, and c current signal of the binding event based on SWV technique.
    Matched MeSH terms: Food Contamination/analysis
  6. Survival of antibiotic resistant Escherichia coli in vacuumpacked keropok lekor: Food safety alert among SME keropok lekor producers
    Wan-Hamat H, Lani MN, Hamzah Y, Alias R, Hassan Z, Mahat NA
    Trop Biomed, 2020 Mar 01;37(1):103-115.
    PMID: 33612722
    The microbiological quality of thirty ready-to-eat (RTE) keropok lekor (a sausage shape Malaysian fish product) was evaluated in comparison to microbiological guidelines for ready to eat foods. The two E. coli isolates were subjected to DNA sequencing, identified and tested for their resistance towards fifteen different antibiotics. The survival and growth of the isolated E. coli strains inoculated in keropok lekor at atmospheric air and vacuum packaging were also evaluated. Results revealed that four samples (13.33%) contained Enterobacteriaceae counts that exceeded the recommended allowable counts of 4.0 log10 CFU/g. Unsatisfactory level of coliforms (< 1.7 log10 CFU/g) was also observed in ten of the samples; two of which contained E. coli (2.1 ± 0.17 and 3.7 ± 0.02 log10 CFU/g), suggesting of poor hygiene and sanitation practices. While the 'Possible E10' E. coli strain was observably resistant towards Nalidixic acid (30µg) alone, B10 E. coli isolate was worryingly resistant towards Ampicillin (10µg), Ceftazidime (30µg), Ciprofloxacin (5µg), Ceftriaxone (30µg), Nalidixic acid (30µg) and Tetracycline (30µg). This study also revealed that the growth and survival of the 'Possible E10' and B10 E. coli strains were not significantly affected by vacuum packaging when stored at both 4°C and 28°C. Therefore, intervention programmes to alert and educate smallmedium enterprisers (SMEs) of keropok lekor producers on food safety as well as potential health risks that can be associated due to inappropriate handling procedures of such product, merits consideration.
    Matched MeSH terms: Food Contamination/analysis*
  7. Monoclonal antibody-based enzyme immunoassay for detection of porcine plasma in fish surimi
    Raja Nhari RMH, Khairil Mokhtar NF, Hanish I, Hamid M, Mohamed Rashidi MAA, Shahidan NM
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2018 May;35(5):807-817.
    PMID: 29285986 DOI: 10.1080/19440049.2017.1420920
    Detection of porcine plasma using indirect ELISA was developed using mAb B4E1 for the prevention of their usage in human food that creates religious and health conflicts. The immunoassay has a CV 
    Matched MeSH terms: Food Contamination/analysis*
  8. Simulation of cross-contamination and decontamination of Campylobacter jejuni during handling of contaminated raw vegetables in a domestic kitchen
    Chai LC, Lee HY, Ghazali FM, Abu Bakar F, Malakar PK, Nishibuchi M, et al.
    J Food Prot, 2008 Dec;71(12):2448-52.
    PMID: 19244897
    Campylobacter jejuni was found to occur at high prevalence in the raw salad vegetables examined. Previous reports describe cross-contamination involving meat; here we investigated the occurrence of cross-contamination and decontamination events in the domestic kitchen via C. jejuni-contaminated vegetables during salad preparation. This is the first report concerning quantitative cross-contamination and decontamination involving naturally contaminated produce. The study was designed to simulate the real preparation of salad in a household kitchen, starting with washing the vegetables in tap water, then cutting the vegetables on a cutting board, followed by slicing cucumber and blanching (heating in hot water) the vegetables in 85 degrees C water. Vegetables naturally contaminated with C. jejuni were used throughout the simulation to attain realistic quantitative data. The mean of the percent transfer rates for C. jejuni from vegetable to wash water was 30.1 to 38.2%; from wash water to cucumber, it was 26.3 to 47.2%; from vegetables to cutting board, it was 1.6 to 10.3%; and from cutting board to cucumber, it was 22.6 to 73.3%. The data suggest the wash water and plastic cutting board as potential risk factors in C. jejuni transmission to consumers. Washing of the vegetables with tap water caused a 0.4-log reduction of C. jejuni attached to the vegetables (most probable number/gram), while rapid blanching reduced the number of C. jejuni organisms to an undetectable level.
    Matched MeSH terms: Food Contamination/analysis*
  9. Survival of SA11 rotavirus in fresh fruit juices of pineapple, papaya, and honeydew melon
    Leong YK, Xui OC, Chia OK
    J Food Prot, 2008 May;71(5):1035-7.
    PMID: 18522042
    Survival of rotavirus in fresh fruit juices of papaya (Caraca papaya L.), honeydew melon (Cucumis melo L.), and pineapple (Ananas comosus [L.] Merr.) was studied. Clarified juices were prepared from pulps of ripe fruits and sterilized by ultrafiltration. One milliliter of juice from each fruit was inoculated with 20 microl of 1 x 10(6) PFU of SA11 rotavirus and sampled immediately (0-h exposure) and 1 and 3 h later at 28 degrees C. Mean viral titers in juices of papaya (pH 5.1) and honeydew melon (pH 6.3) at 1 and 3 h were not significantly different from titers at 0-h exposure. Mean viral titers in juices from pineapples with ripening color indices of 3 (pH 3.6) and 6 (pH 3.7) at 1-h exposure (color index 3: 4.0 +/- 1.7 x 10(4); color index 6: 2.3 +/- 0.3 x 10(5)) and 3-h exposure (color index 3: 1.1 +/- 0.4 x 10(4); color index 6:1.3 +/- 0.6 x 10(5)) were significantly lower than titers at 0-h exposure (color index 3: 5.7 +/- 2.9 x 10(5); color index 6: 7.4 +/- 1.3 x 10(5)). Virus titers in pineapple juices of color index 3 were significantly lower than titers of the virus in juices of index 6. In cell culture medium (pH 7.4), SA11 titer remained stable over 3 h at 28 degrees C. However, at pH 3.6, the virus titer was reduced to a level not significantly different from that of the virus in pineapple juice of color index 6 (pH 3.7). In conclusion, papaya and honeydew melon juices, in contrast to pineapple juice, have the potential to transmit rotavirus. Inactivation of SA11 virus in pineapple juice can be possibly attributed to low pH and constituent(s) in the juice.
    Matched MeSH terms: Food Contamination/analysis*
  10. Enterobacteriaceae in dehydrated powdered infant formula manufactured in Indonesia and Malaysia
    Estuningsih S, Kress C, Hassan AA, Akineden O, Schneider E, Usleber E
    J Food Prot, 2006 Dec;69(12):3013-7.
    PMID: 17186672
    To determine the occurrence of Salmonella and Shigella in infant formula from Southeast Asia, 74 packages of dehydrated powdered infant follow-on formula (recommended age, > 4 months) from five different manufacturers, four from Indonesia and one from Malaysia, were analyzed. None of the 25-g test portions yielded Salmonella or Shigella. However, further identification of colonies growing on selective media used for Salmonella and Shigella detection revealed the frequent occurrence of several other Enterobacteriaceae species. A total of 35 samples (47%) were positive for Enterobacteriaceae. Ten samples (13.5%) from two Indonesian manufacturers yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. (n = 12), Escherichia hermanii (n = 10), Enterobacter cloacae (n = 8), Klebsiella pneumoniae subsp. pneumoniae (n = 3), Citrobacter spp. (n = 2), Serratia spp. (n = 2), and Escherichia coli (n = 2). To our knowledge, this is the first report to describe the contamination of dehydrated powdered infant formula from Indonesia with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Improper preparation and conservation of these products could result in a health risk for infants in Indonesia.
    Matched MeSH terms: Food Contamination/analysis*
  11. Prevalence and genetic characterization of Vibrio vulnificus in raw seafood and seawater in Malaysia
    Paydar M, Thong KL
    J Food Prot, 2013 Oct;76(10):1797-800.
    PMID: 24112583 DOI: 10.4315/0362-028X.JFP-13-141
    Vibrio vulnificus is a highly invasive human pathogen that exists naturally in estuarine environment and coastal waters. In this study, we used different PCR assays to detect V. vulnificus in 260 seafood and 80 seawater samples. V. vulnificus was present in about 34 (13%) of the 260 seafood samples and 18 (23%) of the 80 seawater samples. Repetitive extragenic palindromic PCR (REP-PCR) and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) were applied to subtype the V. vulnificus isolates. Twenty-five REP profiles and 45 ERIC profiles were observed, and the isolates were categorized into 9 and 10 distinct clusters at the similarity of 80%, by REP-PCR and ERIC-PCR, respectively. ERIC-PCR is more discriminative than REP-PCR in subtyping V. vulnificus, demonstrating high genetic diversity among the isolates.
    Matched MeSH terms: Food Contamination/analysis*
  12. Level of chemical and microbiological contaminations in chili bo (paste)
    Zaini NA, Harith HH, Olusesan AT, Zulkifli AH, Bakar FA, Osman A, et al.
    J Food Prot, 2010 Mar;73(3):541-6.
    PMID: 20202342
    The objective of this study was to determine the level of preservatives and microbiological loads in various brands of commercially available chili bo (paste). Fifteen different brands of chili bo obtained from the local market and hypermarkets were analyzed for pH, moisture and benzoic acid content, microbiological loads (aerobic, anaerobic, aerobic spores, and fungi), and thermophilic microorganisms. Results showed that both moisture content and pH vary among samples. The concentrations of benzoic acid detected in chili bo were found to be in the range of 537 to 5,435 mg/kg. Nine of fifteen brands were found to exceed the maximum level permitted by the Malaysian Food Law in accordance with the Codex Alimentarius (1,000 mg/kg for benzoic acid). An apparent correlation between benzoic acid concentration and microbiological loads present in the chili bo was observed. The microbiological loads were found to be relatively low in the end products containing high amounts of benzoic acid. The heat-resistant (70 to 80 degrees C) microorganisms present in chili bo were identified as Ochrobacterum tritici, Stenotrophomonas rhizophila, Microbacterium maritypicum, Roseomonas spp., CDC group II-E subgroup A, Flavimonas oryzihabitans, and Pseudomonas aeruginosa, with M. maritypicum being the most frequently found (in 9 of 15 samples) microorganism. Most of these identified microorganisms were not known to cause foodborne illnesses.
    Matched MeSH terms: Food Contamination/analysis*
  13. Laboratory study of Vibrio cholerae O1 survival on three types of boiled rice (Oryza sativa L.) held at room temperature
    Huat JT, Leong YK, Lian HH
    J Food Prot, 2008 Dec;71(12):2453-9.
    PMID: 19244898
    This study examined whether the survival of Vibrio cholerae O1 on contaminated cooked rice was influenced by the type of rice. Vibrios survived unchanged on clumps of glutinous white rice (wet, grains adhered) held at room temperature for 24 h. On nonglutinous white rice (slightly moist, grains separate), 30% viable vibrios remained at 24 h. On nonglutinous brown rice (moist, separate, covered with a mucus-like substance), the number of vibrios increased 2.7-fold at 24 h. Survival rates of vibrios on the surfaces of a row of five cooked rice grains after 2 h of exposure at room temperature were 86, 29, 12, and 4% for glutinous rice, white rice, and the endosperm and pericarp of brown rice, respectively. (Each boiled brown rice grain surface was partly pericarp and partly endosperm, which became exposed by a rupture of the pericarp.) Covering each inoculated grain with a similar cooked rice grain surface increased the corresponding figures to 93, 99, 60, and 94%. Scanning electron microscopy revealed that each type of cooked grain surface possessed a distinct microtopography. For example, the surfaces of glutinous rice grains consisted of separated overlapping strips with many holes, while the pericarps of brown rice were flat interspersed with small pits. In conclusion, each type of boiled rice produced a distinct survival pattern of V. cholerae O1 caused by both the distinct gross features and the fine surface characteristics of the rice. The significance of this finding is that the type of rice consumed can be a factor in cholera transmission by contaminated rice.
    Matched MeSH terms: Food Contamination/analysis*
  14. Simulation of improper food hygiene practices: A quantitative assessment of Vibrio parahaemolyticus distribution
    Malcolm TTH, Chang WS, Loo YY, Cheah YK, Radzi CWJWM, Kantilal HK, et al.
    Int J Food Microbiol, 2018 Nov 02;284:112-119.
    PMID: 30142576 DOI: 10.1016/j.ijfoodmicro.2018.08.012
    Kitchen mishandling practices contribute to a large number of foodborne illnesses. In this study, the transfer and cross-contamination potential of Vibrio parahaemolyticus from bloody clams to ready-to-eat food (lettuce) was assessed. Three scenarios were investigated: 1) direct cross-contamination, the transfer of V. parahaemolyticus from bloody clams to non-food contact surfaces (hands and kitchen utensils) to lettuce (via slicing), was evaluated; 2) perfunctory decontamination, the efficacy of two superficial cleaning treatments: a) rinsing in a pail of water, and b) wiping with a kitchen towel, were determined; and 3) secondary cross-contamination, the microbial transfer from cleaning residuals (wash water or stained kitchen towel) to lettuce was assessed. The mean of percent transfer rates through direct contact was 3.6%, and an average of 3.5% of total V. parahaemolyticus was recovered from sliced lettuce. The attempted treatments reduced the transferred population by 99.0% (rinsing) and 94.5% (wiping), and the relative amount of V. parahaemolyticus on sliced lettuce was reduced to 0.008%. V. parahaemolyticus exposure via secondary cross-contamination was marginal. The relative amount of V. parahaemolyticus recovered from washed lettuce was 0.07%, and the transfers from stained kitchen towel to lettuce were insubstantial. Our study highlights that V. parahaemolyticus was readily spread in the kitchen, potentially through sharing of non-food contact surfaces. Results from this study can be used to better understand and potentially raising the awareness of proper handling practices to avert the spread of foodborne pathogens.
    Matched MeSH terms: Food Contamination/analysis
  15. Fulltext The use of innovative and efficient nanocomposite (magnetic graphene oxide) for the reduction on of Fusarium mycotoxins in palm kernel cake
    Pirouz AA, Selamat J, Iqbal SZ, Mirhosseini H, Karjiban RA, Bakar FA
    Sci Rep, 2017 Sep 29;7(1):12453.
    PMID: 28963539 DOI: 10.1038/s41598-017-12341-3
    Adsorption plays an important role in the removal of mycotoxins from feedstuffs. The main objective of this study was to investigate the efficacy of using magnetic graphene oxide nanocomposites (MGO) as an adsorbent for the reduction of Fusarium mycotoxins in naturally contaminated palm kernel cake (PKC). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to assess the mycotoxins in animal feed. Target mycotoxins included the zearalenone (ZEA), the fumonisins (FB1 and FB2) and trichothecenes (deoxynivalenol (DON), HT-2 and T-2 toxin). Response surface methodology (RSM) was applied to investigate the effects of time (3-7 h), temperature (30-50 °C) and pH (3-7) on the reduction. The response surface models with (R2 = 0.94-0.99) were significantly fitted to predict mycotoxins in contaminated PKC. Furthermore, the method ensured a satisfactory adjustment of the polynomial regression models with the experimental data except for fumonisin B1 and B2, which decrease the adsorption of magnetic graphene oxide (MGO). The optimum reduction was performed at pH 6.2 for 5.2 h at of 40.6 °C. Under these optimum conditions, reduced levels of 69.57, 67.28, 57.40 and 37.17%, were achieved for DON, ZEA, HT-2, and T-2, respectively.
    Matched MeSH terms: Food Contamination/analysis
  16. Fulltext Electrochemical Immunosensor for Detection of Aflatoxin B₁ Based on Indirect Competitive ELISA
    Azri FA, Sukor R, Selamat J, Abu Bakar F, Yusof NA, Hajian R
    Toxins (Basel), 2018 May 11;10(5).
    PMID: 29751668 DOI: 10.3390/toxins10050196
    Mycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B₁ (AFB₁) was successfully developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Various parameters of ELISA, including antigen⁻antibody concentration, blocking agents, incubation time, temperature and pH of reagents, were first optimized in a 96-well microtiter plate to study the antigen⁻antibody interaction and optimize the optimum parameters of the assay. The optimized assay was transferred onto the multi-walled carbon nanotubes/chitosan/screen-printed carbon electrode (MWCNTs/CS/SPCE) by covalent attachment with the aid of 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Competition occurred between aflatoxin B₁-bovine serum albumin (AFB₁⁻BSA) and free AFB₁ (in peanut sample and standard) for the binding site of a fixed amount of anti-AFB₁ antibody. Differential pulse voltammetry (DPV) analysis was used for the detection based on the reduction peak of TMB(ox). The developed immunosensor showed a linear range of 0.0001 to 10 ng/mL with detection limit of 0.3 pg/mL. AFB₁ analysis in spiked peanut samples resulted in recoveries between 80% and 127%. The precision of the developed immunosensor was evaluated by RSD values (n = 5) as 4.78% and 2.71% for reproducibility and repeatability, respectively.
    Matched MeSH terms: Food Contamination/analysis
  17. Natural occurrence of aflatoxins and ochratoxin A in processed spices marketed in Malaysia
    Ali N, Hashim NH, Shuib NS
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2015;32(4):518-32.
    PMID: 25658149 DOI: 10.1080/19440049.2015.1011712
    The analysis of aflatoxins (B1, B2, G1 and G2) and ochratoxin A (OTA) was performed in processed spices marketed in Penang, Malaysia, using immunoaffinity columns and HPLC equipped with fluorescence detector (HPLC-FD). The processed powdered spices analysed include dried chilli, fennel, cumin, turmeric, black and white pepper, poppy seed, coriander, 'garam masala', and mixed spices for fish, meat and chicken curry. Two different studies were carried out. The limit of detection (LOD) was 0.01 ng g(-1) for each aflatoxin (AF) and 0.10 ng g(-1) for OTA (signal-to-noise ratio = 3:1). In the first study, 34 commercial processed spices analysed with a mean level, range and incidence of positive samples for total AF were 1.61 ng g(-1), 0.01-9.34 ng g(-1) and 85%, respectively, and for AFB1 were 1.38 ng g(-1), 0.01-7.68 ng g(-1) and 85%, respectively. The mean level, range and incidence of positive samples for OTA were 2.21 ng g(-1), 0.14-20.40 ng g(-1) and 79%, respectively. Natural co-occurrence of AF and OTA was found in 25 (74%) samples. In the second study of 24 commercial processed spices, the mean level, range and incidence of positive samples for total AF were 8.38 ng g(-1), 0.32-31.17 ng g(-1) and 88%, respectively, and for AFB1 were 7.31 ng g(-1), 0.32-28.43 ng g(-1) and 83%, respectively. Fifteen positive samples for total AF and two positive samples for OTA exceeded the permissible Malaysian limit of 5 ng g(-1). Contamination of both mycotoxins in spices may represent another route of exposure to consumers due to their frequent and prolonged consumption, as spices are common ingredients in popular dishes among Asian countries.
    Matched MeSH terms: Food Contamination/analysis*
  18. Use of differential scanning calorimetry to detect canola oil (Brassica napus L.) adulterated with lard stearin
    Marikkar JM, Rana S
    J Oleo Sci, 2014;63(9):867-73.
    PMID: 25174673
    A study was conducted to detect and quantify lard stearin (LS) content in canola oil (CaO) using differential scanning calorimetry (DSC). Authentic samples of CaO were obtained from a reliable supplier and the adulterant LS were obtained through a fractional crystallization procedure as reported previously. Pure CaO samples spiked with LS in levels ranging from 5 to 15% (w/w) were analyzed using DSC to obtain their cooling and heating profiles. The results showed that samples contaminated with LS at 5% (w/w) level can be detected using characteristic contaminant peaks appearing in the higher temperature regions (0 to 70°C) of the cooling and heating curves. Pearson correlation analysis of LS content against individual DSC parameters of the adulterant peak namely peak temperature, peak area, peak onset temperature indicated that there were strong correlations between these with the LS content of the CaO admixtures. When these three parameters were engaged as variables in the execution of the stepwise regression procedure, predictive models for determination of LS content in CaO were obtained. The predictive models obtained with single DSC parameter had relatively lower coefficient of determination (R(2) value) and higher standard error than the models obtained using two DSC parameters in combination. This study concluded that the predictive models obtained with peak area and peak onset temperature of the adulteration peak would be more accurate for prediction of LS content in CaO based on the highest coefficient of determination (R(2) value) and smallest standard error.
    Matched MeSH terms: Food Contamination/analysis*
  19. Sol-gel hybrid methyltrimethoxysilane-tetraethoxysilane as a new dispersive solid-phase extraction material for acrylamide determination in food with direct gas chromatography-mass spectrometry analysis
    Omar MM, Wan Ibrahim WA, Elbashir AA
    Food Chem, 2014 Sep 1;158:302-9.
    PMID: 24731346 DOI: 10.1016/j.foodchem.2014.02.045
    A sol-gel hybrid sorbent, methyltrimethoxysilane-tetraethoxysilane (MTMOS-TEOS) was successfully used as new dispersive solid phase extraction (dSPE) sorbent material in the determination of acrylamide in several Sudanese foods and analysis using GC-MS. Several important dSPE parameters were optimised. Under the optimised conditions, excellent linearity (r(2)>0.9998) was achieved using matrix matched standard calibration in the concentration range 50-1000 μg kg(-1). The limits of detection (LOD) and limit of quantification ranged from 9.1 to 12.8 μg/kg and 27.8-38.9 μg/kg, respectively. The precision (RSD%) of the method was ⩽6.6% and recoveries of acrylamide obtained were in the range of 88-103%, (n=3). The LOD obtained is comparable with the LODs of primary secondary amine dSPE. The proposed MTMOS-TEOS dSPE method is direct and safe for acrylamide analysis, showed reliable method validation performances and good cleanup effects. It was successfully applied to the analysis of acrylamide in real food samples.
    Matched MeSH terms: Food Contamination/analysis*
  20. Contamination of food samples from Malaysia with polychlorinated dibenzo-p-dioxins and dibenzofurans and estimation of human intake
    Leong YH, Chiang PN, Jaafar HJ, Gan CY, Majid MI
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2014 Apr;31(4):711-8.
    PMID: 24392728 DOI: 10.1080/19440049.2014.880519
    A total of 126 food samples, categorised into three groups (seafood and seafood products, meat and meat products, as well as milk and dairy products) from Malaysia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The concentration of PCDD/Fs that ranged from 0.16 to 0.25 pg WHO05-TEQ g(-1) fw was found in these samples. According to the food consumption data from the Global Environment Monitoring System (GEMS) of the World Health Organization (WHO), the dietary exposures to PCDD/F from seafood and seafood products, meat and meat products, as well as milk and dairy products for the general population in Malaysia were 0.064, 0.183 and 0.736 pg WHO05-TEQ kg(-1) bw day(-1), respectively. However, the exposure was higher in seafood and seafood products (0.415 pg WHO05-TEQ kg(-1) bw day(-1)) and meat and meat products (0.317 pg WHO05-TEQ kg(-1) bw day(-1)) when the data were estimated using the Malaysian food consumption statistics. The lower exposure was observed in dairy products with an estimation of 0.365 pg WHO05-TEQ kg(-1) bw day(-1). Overall, these dietary exposure estimates were much lower than the tolerable daily intake (TDI) as recommended by WHO. Thus, it is suggested that the dietary exposure to PCDD/F does not represent a risk for human health in Malaysia.
    Matched MeSH terms: Food Contamination/analysis*
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