Displaying publications 1 - 20 of 57 in total

Abstract:
Sort:
  1. Sultana S, Azlan A, Mohd Desa MN, Mahyudin NA, Anburaj A
    PMID: 38284970 DOI: 10.1080/19440049.2024.2304577
    Regular testing and systematic investigation play a vital role to ensure product safety. Until now, the existing food authentication techniques have been based on proteins, lipids, and nucleic acid-based assays. Among various deoxyribonucleic acid (DNA)-based methods, the recently developed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) based bio-sensing is an innovative and fast-expanding technology. The CRISPR/Cas-9 is known as Clustered Regularly Interspaced Short Palindromic Repeats due to the flexibility and simplicity of the CRISPR/Cas9 site-specific editing tool has been applied in many biological research areas such as Gene therapy, cell line development, discovering mechanisms of disease, and drug discovery. Nowadays, the CRISPR-Cas system has also been introduced into food authentication via detecting DNA barcodes of poultry and livestock both in processed and unprocessed food samples. This review documents various DNA based approaches, in an accessible format. Future CRISPR technologies are forecast while challenges are outlined.
  2. Liu C, Wang ST, Tan CH, Lin ZE, Lee WJ
    PMID: 38422382 DOI: 10.1080/19440049.2024.2319271
    Glycidyl esters (GEs) and 3-monochloropropanediol esters (3-MCPDEs) are process contaminants commonly found in refined edible oils which are often added to infant formulas. The Taiwan Food and Drug Administration (TFDA) launched regulations for GEs in infant formulas that went into effect on 1 July 2021. To investigate levels of GEs and 3-MCPDEs in infant formula powder, 45 products were sampled and analysed during 2020-2021. The contents of GEs and 3-MCPDEs in formulas of different brands significantly varied, but their concentrations in all of the formulas complied with European Union (EU) regulations. Infant formulas containing palm oil had significantly higher 3-MCPDE levels in both extracted oils and milk powder than those without palm oil. Concentrations of GEs and 3-MCPDEs in infant formula powder and extracted oils were significantly lower in products from Europe than those from Australia and New Zealand. Infants aged 0-1 years in Taiwan who consumed only infant formula showed a margin of exposure (MoE) exceeding 25,000. Mean consumer exposures to 3-MCPDEs stayed below the tolerable daily intake (TDI), while high exposures at the 95th percentile (P95) exceeded the TDI by 1.7-fold. Herein, we present the changing trends in the risk assessment results of infant formula across various countries in the decade. Implementation of regulations and mitigation strategy effectively reduced the risk of infants being exposed to GEs and 3-MCPDEs through infant formula.
  3. Mokhtar NFK, Shun YQ, Raja Nhari RMH, Mohamad NA, Shahidan NM, Warsanah IH, et al.
    PMID: 38190283 DOI: 10.1080/19440049.2023.2298476
    The inclusion of ingredients derived from pigs in highly processed consumer products poses a significant challenge for DNA-targeted analytical enforcement, which could be overcome by using digital PCR. However, most species detection methods use digital PCR to target single-copy nuclear genes, which limits their sensitivity. In this work, we examined the performance of a nanoplate-based digital PCR method that targets multi-copy nuclear (MPRE42) and mitochondrial (Cytb) genes. Poor separation of positive and negative partitions, as well as a 'rain effect' were obtained in the porcine-specific MPRE42 assay. Among the optimization strategies examined, the inclusion of restriction enzymes slightly improved the separation of positive and negative partitions, but a more extensive 'rain effect' was observed. The high copy number of the MPRE42 amplicon is hypothesized to contribute to the saturation of the positive signal. In contrast, the porcine-specific Cytb assay achieved perfect separation of positive and negative partitions with no 'rain effect'. This assay can detect as little as 0.4 pg of pork DNA, with a sensitivity of 0.05% (w/w) in a pork-chicken mixture, proving its applicability for detecting pork in meat and meat-based products. For the MPRE42 assay, potential applications in highly degraded products such as gelatin and lard are anticipated.
  4. Yung YL, Lakshmanan S, Chu CM, Tham HJ, Kumaresan S
    PMID: 38011619 DOI: 10.1080/19440049.2023.2283873
    The presence of 3-monochloropropane-1,2 diol ester (3-MCPDE) and glycidyl ester (GE) in processed palm oils is of concern, as these oils are widely used for edible purposes. The mitigation method studied here optimizes the removal of chloride through water washing of crude palm oil (CPO), to limit the formation of 3-MCPDE. The contaminant removal obtained via washing CPO supports the quantitative findings. By utilizing 5% water in the washing step, water-soluble chlorides in CPO are removed by up to 76%, resulting in a 71% reduction of 3-MCPDE to within statutory limits. In this study, a linear correlation was developed between the chloride and the corresponding 3-MCPDE with a correlation coefficient (R2) of 0.99. Using the correlations, 1.0 mg/kg of 3-MCPDE in refined, bleached and deodorized palm oil (RBDPO) will be obtained from CPO with 1.2 mg/kg chloride with 7% wash water usage. The study also showed minor GE reduction between 7 and 11% was attained after water washing.
  5. Anual ZF, Ahmad NI, Anak Robun C, Ahmad Suhaimi LR, Surawi NH, Sudin K, et al.
    PMID: 37883683 DOI: 10.1080/19440049.2023.2272726
    Food contaminated with heavy metals poses a serious threat to consumers. This study aims to assess levels of lead (Pb) and cadmium (Cd) in offals of chicken, cattle, and pig as well as tin (Sn) in canned food. A total of 378 offal samples was collected from wet markets, while 218 canned food samples were purchased locally. Samples were digested using a microwave before analysis with inductively coupled plasma mass spectrometry (ICP-MS). Pb was determined, highest in cattle lung (0.11 ± 0.20 mg/kg) followed by cattle spleen (0.09 ± 0.14 mg/kg), and cattle tripe (0.09 ± 0.12 mg/kg). For Cd, the highest concentrations were in cattle liver (0.13 ± 0.12 mg/kg), pig liver (0.08 ± 0.05 mg/kg), and chicken liver (0.03 ± 0.02 mg/kg). Significant variations of Sn levels existed in different canned food categories with 3.21% samples (n = 7) exceeded the maximum level of 250 mg/kg set by Codex Alimentarius. All offal samples were below the Malaysian regulatory limits, indicating their safety for human consumption. However, Sn levels varied significantly among canned food categories, with the highest levels found in canned pineapple chunks in syrup, mixed pineapple cubes in syrup, pineapple slices and longan. Samples exceeding the maximum level set by Codex Alimentarius may pose a risk to consumers.
  6. Ramli NAS, Roslan NA, Abdullah F, Bilal B, Ghazali R, Abd Razak RA, et al.
    PMID: 37682685 DOI: 10.1080/19440049.2023.2255290
    Esters of 2- and 3-monochloropropanediol (2-MCPDE, 3-MCPDE) and glycidol (GE) are regarded as process contaminants that are found in refined vegetable oils and oil-based foods. Since glycerol is produced during fat splitting, saponification and biodiesel production, it is important to have methods for determining contaminants that might be formed during these processes. Due to the use of glycerol as a food additive, data on the presence of compounds of toxicological concern, including 3-MCPD, are of interest. This study focuses on modifying the indirect analysis of 2-MCPDE, 3-MCPDE and GE using GC-MS based on the AOCS Official Method Cd 29a-13, validating the modified method, and quantifying 2-MCPDE, 3-MCPDE and GE in glycerol. The AOCS Cd 29a-13 method was modified at the initial stage of sample preparation in which the targeted esters were extracted from glycerol by vortex-assisted extraction before sample analysis. This modification was performed based on the polarity of all compounds involved. The calibration functions for all analytes were fitted to linear regression with R2 above 0.99. Limits of detection (LOD) 0.02, 0.01 and 0.02 mg kg-1 were obtained for 2-MCPDE, 3-MCPDE and GE, respectively. Spiked glycerol with 3-MCPDE and 2-MCPDE (0.25, 0.51 and 1.01 mg kg-1) and GE (0.58, 1.16 and 2.32 mg kg-1) were used for recovery and precision measurements. Recoveries of 100-108%, 101-103%, and 93-99% were obtained for 2-MCPDE, 3-MCPDE and GE, respectively. Acceptable precision levels with relative standard deviations ranged from 3.3% to 8.3% were obtained for repeatability and intermediate precision. The validated method was successfully applied for the analysis of the target compounds in refined glycerol from commercial plants, which showed that 2-MCPDE, 3-MCPDE and GE levels in the analysed samples were below the detection limit.
  7. Yung YL, Lakshmanan S, Chu CM, Kumaresan S, Tham HJ
    PMID: 37549246 DOI: 10.1080/19440049.2023.2235608
    The rising concern about the presence of 3-monochloropropane 1,2 diol ester (3-MCPDE) and glycidyl ester (GE) in food has prompted much research to be conducted. Some process modifications and the use of specific chemicals have been employed to mitigate both 3-MCPDE and GE. Alkalisation using NaOH, KOH, alkali metals or alkaline earth metals and post sparging with steam or ethanol and short path distillation have shown simultaneous mitigation of 51-91% in 3-MCPDE and of 13-99% in GE, both contaminants achieved below 1000 µg/kg. Some of the mitigation methods have resulted in undesirable deterioration in other parameters of the refined oil. When the processed oil is used in food processing, it results in changes to 3-MCPDE and GE. Repeated deep frying above 170 °C in the presence of NaCl and baking at 200 °C with flavouring (dried garlic and onion), resulted in increased 3-MCPDE. Repeated frying in the presence of antioxidants (TBHQ, rosemary and phenolics) decreased 3-MCPDE in processed food. The GE content in foods tends to decline with time, indicating instability of GE's epoxide ring.
  8. Raja Nhari RMH, Soh JH, Khairil Mokhtar NF, Mohammad NA, Mohd Hashim A
    PMID: 37535014 DOI: 10.1080/19440049.2023.2242955
    Lateral flow devices (LFDs) are straightforward scientific tools that have made substantial advances in recent years. They have been used in many fields including the meat industry to detect disease markers, determine meat freshness or meat species determination. They are, therefore, significant in the research of meat adulteration by mixed animal species, because food component authenticity is a serious concern encompassing health, economic, legal, and religious issues. Pork adulteration is one of the most crucial issues in the global meat industry. In this review, we discuss the various types of LFDs and recent research on the development of LFDs as an authenticity tool for detecting pig additives in meat-based products, and how regulatory authorities could adopt LFDs for their workflows. Despite the benefits of rapidity, simplicity, low cost, high sensitivity, and specificity, researchers face challenges when using LFD as a final confirmation test. Future directions are suggested for globalising the use of LFD as a halal authentication method.
  9. Muhamad Rosli SH, Lau MS, Khalid T, Maarof SK, Jeyabalan S, Sirdar Ali S, et al.
    PMID: 36947708 DOI: 10.1080/19440049.2023.2183068
    3-Monochloropropane-1,2-diol esters (3-MCPDE) are food contaminants commonly found in refined vegetable oils and fats, which have possible carcinogenic implications in humans. To investigate this clinically, we conducted an occurrence level analysis on eight categories of retail and cooked food commonly consumed in Malaysia. This was used to estimate the daily exposure level, through a questionnaire-based case-control study involving 77 subjects with renal cancer, with 80 matching controls. Adjusted Odds Ratio (AOR) was calculated using the multiple logistic regression model adjusted for confounding factors. A pooled estimate of total 3-MCPDE intake per day was compared between both groups, to assess exposure and disease outcome. Among the food categories analysed, vegetable fats and oils recorded the highest occurrence levels (mean: 1.91 ± 1.90 mg/kg), significantly more than all other food categories (p 
  10. Nik Azmi NNA, Tan TC, Ang MY, Leong YH
    PMID: 36602442 DOI: 10.1080/19440049.2022.2163054
    The presence of 3-monochloropropanediol esters (3-MCPDE), 2-monochloropropanediol esters (2-MCPDE) and glycidyl esters (GE) in infant formula products has raised serious concerns. They incorporate vegetable oils, particularly palm-based oils, which are well-known to contain large amounts of these process contaminants. An analysis was conducted on infant formula samples (n = 16) obtained from the Malaysian market to determine the levels of 3-MCPDE, 2-MCPDE and GE using gas chromatography-mass spectrometry (GC-MS). The method was validated, with a limit of quantification (LOQ) on instrument of 0.10 µg/g for all analytes. The median concentrations of 3-MCPDE, 2-MCPDE and GE in infant formula in this study were 0.008 µg/g, 0.003 µg/g and 0.002 µg/g respectively. The estimated dietary intakes calculated from consumption of infant formula show higher exposures to infants within the age group of 0 to 5 months, highest for GE (1.61 µg/kg bw/day), followed by 3-MCPDE (0.68 µg/kg bw/day) and 2-MCPDE (0.41 µg/kg bw/day) compared to the age group of 6 to 12 months. Only one sample, relating to GE exposure is a potential risk for both age groups with MOE value below 25,000.
  11. Kua JM, Azizi MMF, Abdul Talib MA, Lau HY
    PMID: 36252206 DOI: 10.1080/19440049.2022.2134591
    Halal authentication has become essential in the food industry to ensure food is free from any prohibited ingredients according to Islamic law. Diversification of food origin and adulteration issues have raised concerns among Muslim consumers. Therefore, verification of food constituents and their quality is paramount. From conventional methods based on physical and chemical properties, various diagnostic methods have emerged relying on protein or DNA measurements. Protein-based methods that have been used in halal detection including electrophoresis, chromatographic-based methods, molecular spectroscopy and immunoassays. Polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) are DNA-based techniques that possess better accuracy and sensitivity. Biosensors are miniatured devices that operate by converting biochemical signals into a measurable quantity. CRISPR-Cas is one of the latest novel emerging nucleic acid detection tools in halal food analysis as well as quantification of stable isotopes method for identification of animal species. Within this context, this review provides an overview of the various techniques in halal detection along with their advantages and limitations. The future trend and growth of detection technologies are also discussed in this review.
  12. Tiong SH, Nair A, Abd Wahid SA, Saparin N, Ab Karim NA, Ahmad Sabri MP, et al.
    PMID: 34407744 DOI: 10.1080/19440049.2021.1960430
    Chlorinated compounds such as sphingolipid-based organochlorine compounds are precursors for the formation of 3-monochlororopanediol (3-MCPD) esters in palm oil. This study evaluates the effects of several factors within the palm oil supply chain on the levels of sphingolipid-based organochlorine, which in turn may influence the formation of 3-MCPD esters during refining. These factors include application of inorganic chlorinated fertiliser in the oil palm plantation, bruising and degradation of oil palm fruits after harvest, recycling of steriliser condensate as water for dilution of crude oil during oil palm milling, water washing of palm oil and different refining conditions. It was observed that bruised and degraded oil palm fruits showed higher content of sphingolipid-based organochlorine than control. In addition, recycling steriliser condensate during milling resulted in elevated content of sphingolipid-based organochlorine in palm oil. However, the content of sphingolipid-based organochlorine compounds was reduced by neutralisation, degumming and bleaching steps during refining. Although water washing of crude palm oils (CPO) prior to refining did not reduce the content of sphingolipid-based organochlorine, it did reduce the formation of 3-MCPD esters through the removal of water-soluble chlorinated compounds. It was found that the use of inorganic chlorinated fertiliser in plantations did not increase the content of chlorinated compounds in oil palm fruits and extracted oil, and hence chlorinated fertiliser does not seem to play a role in the formation of 3-MCPD esters in palm oil. Overall, this study concluded that lack of freshness and damage to the fruits during transport to mills, combined with water and oil recycling in mills are the major contributors of chlorinated precursor for 3-MCPD esters formation in palm oil.
  13. Uddin SMK, Hossain MAM, Chowdhury ZZ, Johan MRB
    PMID: 34077338 DOI: 10.1080/19440049.2021.1925748
    Food fraud is a global problem raising increased concerns during the past decades and food authenticity is now a burning issue. Beef, buffalo, chicken, duck, goat, sheep, and pork are heavily consumed meats bearing nutritional, economic and cultural/religious importance and are often found to be adulterated in raw and processed states. To authenticate these species, we developed and validated a highly specific multiplex (heptaplex) PCR assay targeting short length amplicons (73-263 bp) using seven pairs of species-specific primer sets targeting mitochondrial cytochrome b (cytb) and NADH dehydrogenase subunit 5 (ND5) genes. Specificity checking (in silico and in vitro) against 25 non-target species revealed no cross-species amplification. The developed multiplex assay was validated with various adulterated and heat-treated (boiled, microwaved and autoclaved) meatball products and were found to show high sensitivity and stability under all processing conditions. The assay was sensitive enough to detect 0.01-0.005 ng of DNA from raw meat and 0.5% (w/w) adulterated meat in mixed matrices. A market survey revealed mislabelling of 95% beef and 15% chicken products while pork products were found pure. Given some advantageous features including short sizes of amplicons, exceptional stability and superior sensitivity, the developed assay could be conveniently used for discriminatory detection of target species with a variety of raw meat as well as processed meat products undergoing extreme processing treatments.
  14. Leong YH, Azmi NI, Majid MIA, Wen S
    PMID: 34014804 DOI: 10.1080/19440049.2021.1922758
    An average 50 ml breast milk samples were collected from 21 lactating primiparous mothers (range 25 to 45 years, mean 33 years), 4-8 weeks after delivery in Penang Island, Malaysia. The geometric mean concentration of the most toxic congeners, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) was 0.14 pg WHO2005-TEQ g-1 zlipid. The most abundant congeners of PCDD/Fs were octachlorodibenzo-p-dioxin (OCDD) (5.9-75.4%), followed by 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1,2,3,4,6,7,8-HpCDD) (1.1-30.7%). The geometric mean level of total dioxins and dl-PCBs was 2.2 pg WHO2005-TEQ g-1 lipid, significantly lower than those in developed countries or highly contaminated areas. The total dioxins and dl-PCBs in pg WHO2005-TEQ levels in breast milk were significantly correlated with years of residence at potential contaminated site. The average daily intake of 11.8 pg WHO2005-TEQ kg-1 body weight was estimated for a breastfed infant at 6 months of age. This demonstrates the exposure risk to infants, especially from Penang region, to these pollutants from human milk intake are potentially high during the lactation period.
  15. Lakshmanan S, Yung YL
    PMID: 33596165 DOI: 10.1080/19440049.2020.1842516
    Chloride reduction in crude palm oil (CPO) of greater than 80% was achieved with water washing conducted at 90°C. Inorganic chloride content in CPO was largely removed through washing, with no significant reduction in the organic chloride. Phosphorous content of CPO reduced by 20%, while trace elements such as calcium, magnesium and iron were also reduced in the washing operation. The 3-MCPDE formed in the refined, bleached and deodorised palm oil displayed (RBDPO) a linear relationship with the chloride level in washed CPO, which could be represented by the equation y = 0.91x, where y is 3-MCPDE and x represents the chloride in RBDPO refined from washed CPO. In plant scale trials using 5% water at 90°C, mild acidification of the wash water at 0.05% reduced chloride by average 76% in washed CPO. Utilising selected bleaching earths, controlled wash water temperature and wash water volume produced low chloride levels in RBDPO. Chloride content less than 1.4 mg kg-1 in plant RBDPO production was achieved, through physical refining of washed CPO containing less than 2 mg kg-1 chloride and would correspond to 3-MCPDE levels of 1.25 mg kg-1 in RBDPO. The 3-MCPDE reduced further to 1.1 mg kg-1 as the chloride level of washed CPO decreased below 1.8 mg kg-1. Chloride has been shown to facilitate the 3-MCPDE formation and its removal in lab scale washing study has yielded lower 3-MCPDE levels formed in RBDPO. In actual plant operations using washed CPO, 3-MCPDE levels below 1.25 mg kg-1 were achieved consistently in RBDPO.
  16. Shaari NA, Ahmad Tarmizi AH, Md Sikin A
    PMID: 33332229 DOI: 10.1080/19440049.2020.1845400
    The study aimed to establish the detection method for bound 3-, 2-MCPD, and glycidol using accelerated solvent extraction (ASE) and gas chromatography mass spectrometry (GC-MS). The ASE was modified for reduced solvent volume and process time to extract lipid from the chocolate spread, infant formula, potato chips, and sweetened creamer. The solvent selected for ASE was a mixture of iso-hexane and acetone at 100°C with the lipid and analyte recovery ranging from 96.9% to 98.6% and 84.1% to 107.5%, respectively. The derivatisation of analytes was adopted from the AOCS method Cd29a-13 for GC-MS analysis. The results showed that the coefficient of determination (R2) of all analytes was >0.99. The limit of detection (LOD) was 0.1 mg kg-1 expressed in lipid basis for both bound 3- and 2-MCPD and 0.2 mg kg-1 expressed in lipid basis for bound glycidol. The limit of quantitation (LOQ) was 0.3 mg kg-1 expressed in lipid basis for both bound 3- and 2-MCPD and 0.6 mg kg-1 expressed in lipid basis for bound glycidol. A blank spiked with 3-monochloropropanediols fatty acid esters (MCPDE) and 2-MCPDE (0.3, 2.1, and 7.2 mg kg-1) and glycidol esters (0.6, 4.7, and 16.6 mg kg-1) were chosen for accuracy and precision tests. The recoveries were 91.7% to 105.9%. Both repeatability and within-laboratory reproducibility of the analysis were within the acceptable level of precision ranging from 1.7% to 16%. This is the first time that a full validation procedure extending to both accuracy and precision tests has been carried out for sweetened creamer and chocolate spread. Overall, the combined protocol of ASE and AOCS Cd29a-13 was successfully validated for both solid and liquid food samples with lipid content from 10% to 30%.
  17. Raja Nhari RMH, Muhammad Zailani AN, Khairil Mokhtar NF, Hanish I
    PMID: 32027553 DOI: 10.1080/19440049.2020.1717645
    The usage of porcine pepsin or other porcine derivatives in food products is a common practice in European, American and certain Asian countries although it creates issues in religious and personnel health concerns. In this study, porcine pepsin was detected using indirect ELISA that involved the anti-pep80510 polyclonal antibody raised against a specific peptide of porcine pepsin, pep80510. The sensitivity of the assay for standard porcine pepsin was 0.008 µg/g. The immunoassay did not cross-react to other animal rennet and milk proteins except for microbial coagulant from Mucor miehie. The recovery of porcine pepsin in spiked cheese curd within the range of CV < 20% while for porcine pepsin in spiked cheese whey the recovery is also within the range of CV% < 20%.
  18. Abd Razak RA, Ahmad Tarmizi AH, Abdul Hammid AN, Kuntom A, Ismail IS, Sanny M
    PMID: 31437078 DOI: 10.1080/19440049.2019.1654139
    This study was conducted to investigate on the effect of different sampling regions of palm-refined oils and fats on the 2- and 3-monochloropropanediol fatty acid esters (MCPDE) and glycidol fatty acid esters (GE) levels. The American Oil Chemists' Society (AOCS) Official Method Cd 29a-13 on the determination of MCPDE and GE in edible oils and fats by acid transesterification was successfully verified and optimised, with slight modification using 7890A Agilent GC system equipped with 5975C quadrupole detector. The determined limits of detection (LOD) for MCPDE were 0.02 mg kg-1 and 0.05 mg kg-1 for GE. The method performance has showed good recovery between 80% and 120% for all pertinent compounds with seven replicates assayed in three separate days. Round robin test with two European laboratories, i.e. Eurofins and SGS, has shown compliance results with those of the present study. Among the sampling regions, only one refinery located in the central region of Malaysia showed a significant increment of the MCPDE and GE levels after refining process. The GE level averaging at 2.5 mg kg-1 was slightly higher than that of 3-MCPDE averaging at 1.3 mg kg-1. Both esters were preferentially partitioned into the liquid phase rather than the solid phase after fractionation. However, the overall results exhibited no direct correlation between the esters content and the different sampling locations of the palm oil products in Malaysia. Analysis of total chlorine content also displayed significant variations between sampling locations which clearly show its effect on the chlorine content in the CPO samples.
  19. Ahmad Nizar NN, Hossain M, Sultana S, Ahamad MN, Johan MR, Ali ME
    PMID: 30945985 DOI: 10.1080/19440049.2019.1584407
    Consumption and exploitation of crocodiles have been rampant for their exotic, nutritive and medicinal attributes. These depredations are alarming and although they have continued to be monitored by wildlife and conservation agencies, unlawful trading of crocodiles shows an increasing trend worldwide. Recently, conventional polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) assays for crocodile have been documented but they are only suitable for identification and cannot quantify adulterations. We described here a quantitative duplex real-time PCR assay with probes to quantify contributions from Crocodylus porosus materials simultaneously. A very short amplicon size of 127bp was used because longer targets could have been broken down in samples, bringing considerable uncertainty in molecular analysis. We have validated a TaqMan probe-based duplex real-time PCR (qPCR) assay for the detection of 0.004 ng DNA in pure state and 0.1% target meat in model chicken meatball. False negative detection was eliminated through an endogenous control (141-bp site of eukaryotic 18S rRNA). Analysis of 12 model chicken meatballs adulterated with C. porosus reflected 96.3-120.2% target recovery at 0.1-10% adulterations. A validation test of 21 commercial food and traditional medicine (TM) crocodile-based products showed 100% effectiveness. Short amplicon sizes, alternative complementary target, exceptional stability and superior sensitivity suggested the assay could be used for the identification and quantitative determination of C. porosus in any food or TM samples even under degraded conditions.
  20. Hossain MAM, Uddin SMK, Chowdhury ZZ, Sultana S, Johan MR, Rohman A, et al.
    PMID: 30865559 DOI: 10.1080/19440049.2019.1580389
    Mislabelling in fish products is a highly significant emerging issue in world fish trade in terms of health and economic concerns. DNA barcoding is an efficient sequencing-based tool for detecting fish species substitution but due to DNA degradation, it is in many cases difficult to amplify PCR products of the full-length barcode marker (~650 bp), especially in severely processed products. In the present study, a pair of universal primers targeting a 198 bp sequence of the mitochondrial 16s rRNA gene was designed for identification of fish species in the processed fish products commonly consumed in Malaysia. The specificity of the universal primers was tested by both in-silico studies using bioinformatics software and through cross-reaction assessment by practical PCR experiments against the DNA from 38 fish species and 22 other non-target species (animals and plants) and found to be specific for all the tested fish species. To eliminate the possibility of any false-negative detection, eukaryotic endogenous control was used during specificity evaluation. The developed primer set was validated with various heat-treated (boiled, autoclaved and microwaved) fish samples and was found to show high stability under all processing conditions. The newly developed marker successfully identified 92% of the tested commercial fish products with 96-100% sequence similarities. This study reveals a considerable degree of species mislabelling (20.8%); 5 out of 24 fish products were found to be mislabelled. The new marker developed in this work is a reliable tool to identify fish species even in highly processed products and might be useful in detecting fish species substitution thus protecting consumers' health and economic interests.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links