The halal status of meat products is an important factor being considered by many parties, especially Muslims. Analytical methods that have good specificity for the authentication of halal meat products are important as quality assurance to consumers. Metabolomic and lipidomic are two useful strategies in distinguishing halal and non-halal meat. Metabolomic and lipidomic analysis produce a large amount of data, thus chemometrics are needed to interpret and simplify the analytical data to ease understanding. This review explored the published literature indexed in PubMed, Scopus, and Google Scholar on the application of chemometrics as a tool in handling the large amount of data generated from metabolomic and lipidomic studies specifically in the halal authentication of meat products. The type of chemometric methods used is described and the efficiency of time in distinguishing the halal and non-halal meat products using chemometrics methods such as PCA, HCA, PLS-DA, and OPLS-DA is discussed.
Adulteration of high-quality meat products using lower-priced meats, such as pork, is a crucial issue that could harm consumers. The consumption of pork is strictly forbidden in certain religions, such as Islam and Judaism. Therefore, the objective of this research was to develop untargeted metabolomics using liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined with chemometrics for analysis of pork in beef meatballs for halal authentication. We investigated the use of non-targeted LC-HRMS as a method to detect such food adulteration. As a proof of concept using six technical replicates of pooled samples from beef and pork meat, we could show that metabolomics using LC-HRMS could be used for high-throughput screening of metabolites in meatballs made from beef and pork. Chemometrics of principal component analysis (PCA) was successfully used to differentiate beef meatballs and pork meatball samples. Partial least square-discriminant analysis (PLS-DA) clearly discriminated between halal and non-halal beef meatball samples with 100% accuracy. Orthogonal projection to latent structures-discriminant analysis (OPLS-DA) perfectly discriminated and classified meatballs made from beef, pork, and a mixture of beef-pork with a good level of fitness (R2X = 0.88, R2Y = 0.71) and good predictivity (Q2 = 0.55). Partial least square (PLS) and orthogonal PLS (OPLS) were successfully applied to predict the concentration of pork present in beef meatballs with high accuracy (R2 = 0.99) and high precision. Thirty-five potential metabolite markers were identified through VIP (variable important for projections) analysis. Metabolites of 1-(1Z-hexadecenyl)-sn-glycero-3-phosphocholine, acetyl-l-carnitine, dl-carnitine, anserine, hypoxanthine, linoleic acid, and prolylleucine had important roles for predicting pork in beef meatballs through S-line plot analysis. It can be concluded that a combination of untargeted metabolomics using LC-HRMS and chemometrics is promising to be developed as a standard analytical method for halal authentication of highly processed meat products.
Beef sausage (BS) is one of the most favored meat products due to its nutrition and good taste. However, for economic purposes, BS is often adulterated with pork by unethical players. Pork consumption is strictly prohibited for religions including Islam and Judaism. Therefore, advanced detection methods are highly required to warrant the halal authenticity of BS. This research aimed to develop a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method to determine the halal authenticity of BS using an untargeted metabolomics approach. LC-HRMS was capable of detecting various metabolites in BS and BS containing pork. The presence of pork in BS could be differentiated using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) with high accuracy. PLS-DA perfectly classified authentic BS and BS containing pork in all concentration levels of pork with R2X = (0.821), R2Y(= 0.984), and Q2 = (0.795). The level of pork in BS was successfully predicted through partial least squares (PLS) and orthogonal PLS (OPLS) chemometrics. Both models gave high R2 (>0.99) actual and predicted values as well as few errors, indicating good accuracy and precision. Identification of discriminating metabolites' potential as biomarker candidates through variable importance for projections (VIP) value revealed metabolites of 2-arachidonyl-sn-glycero-3-phosphoethanolamine, 3-hydroxyoctanoylcarnitine, 8Z,11Z,14Z-eicosatrienoic acid, D-(+)-galactose, oleamide, 3-hydroxyhexadecanoylcarnitine, arachidonic acid, and α-eleostearic acid as good indicators to detect pork. It can be concluded that LC-HRMS metabolomics combined with PCA, PLS-DA, PLS, and OPLS was successfully used to detect pork adulteration in beef sausages. The results imply that LC-HRMS untargeted metabolomics in combination with chemometrics is a promising alternative as an analytical technique to detect pork in sausage products. Further analysis of larger samples is required to warrant the reproducibility.
Chicken is known to be the most common meat type involved in food mislabeling and adulteration. Establishing a method to authenticate chicken content precisely and identifying chicken breeds as declared in processed food is crucial for protecting consumers' rights. Categorizing the authentication method into their respective omics disciplines, such as genomics, transcriptomics, proteomics, lipidomics, metabolomics, and glycomics, and the implementation of bioinformatics or chemometrics in data analysis can assist the researcher in improving the currently available techniques. Designing a vast range of instruments and analytical methods at the molecular level is vital for overcoming the technical drawback in discriminating chicken from other species and even within its breed. This review aims to provide insight and highlight previous and current approaches suitable for countering different circumstances in chicken authentication.
Meat is an important food source that can provide a significant amount of protein for human development. The occurrence of bacteria that are resistant to antimicrobials in meat poses a public health risk. This study evaluated the occurrence and antimicrobial resistance of E. coli (Escherichia coli) isolated from raw meats, ready-to-eat (RTE) meats and their related samples in Ghana. E. coli was isolated using the USA-FDA Bacteriological Analytical Manual and phenotypic antimicrobial susceptibility test was performed by the disk diffusion method. Of the 200 examined meats and their related samples, 38% were positive for E. coli. Notably, E. coli was highest in raw beef (80%) and lowest in RTE pork (0%). The 45 E. coli isolates were resistant ≥ 50% to amoxicillin, trimethoprim and tetracycline. They were susceptible to azithromycin (87.1%), chloramphenicol (81.3%), imipenem (74.8%), gentamicin (72.0%) and ciprofloxacin (69.5%). A relatively high intermediate resistance of 33.0% was observed for ceftriaxone. E. coli from raw meats, RTE meats, hands of meat sellers and working tools showed some differences and similarities in their phenotypic antimicrobial resistance patterns. Half (51.1%) of the E. coli isolates exhibited multidrug resistance. The E. coli isolates showed twenty-two different resistant patterns, with a multiple antibiotic resistance index of 0.0 to 0.7. The resistant pattern amoxicillin (A, n = 6 isolates) and amoxicillin-trimethoprim (A-TM, n = 6 isolates) were the most common. This study documents that raw meats, RTE meats and their related samples in Ghana are potential sources of antimicrobial-resistant E. coli and pose a risk for the transfer of resistant bacteria to the food chain, environment and humans.
Crab meat is a valuable source of proteins and functional lipids and it is widely consumed worldwide. However, the prevalence of crab allergy has increased over the past few years. In order to understand crab allergy better, it is necessary to identify crab allergens. The aim of the present study was to compare the IgE-binding proteins of raw and cooked extracts of mud crab (Scylla serrata). Raw and cooked extracts of the mud crab were prepared. Protein profiles and IgE reactivity patterns were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by immunoblotting using sera from 21 skin prick test (SPT) positive patients. In SDS-PAGE, 20 protein bands (12 to 250 kDa) were observed in the raw extract while the cooked extract demonstrated fewer bands. Protein bands between 40 to 250 kDa were sensitive to heat denaturation and no longer observed in the cooked extract. In immunoblotting experiments, raw and cooked extracts demonstrated 11 and 4 IgE-binding proteins, respectively, with molecular weights of between 23 and 250 kDa. A heat-resistant 36 kDa protein, corresponding to crab tropomyosin was identified as the major allergen of both extracts. In addition, a 41 kDa heat-sensitive protein believed to be arginine kinase was shown to be a major allergen of the raw extract. Other minor allergens were also observed at various molecular weights.
This review places emphasis on the food and water borne protozoal diseases like, cryptosporidiosis, giardiasis, cyclosporiasis, and toxoplasmosis which are endemic in many parts of the world. The article addresses cryptosporidiosis, giardiasis, cyclosporiasis, and toxoplasmosis. Cryptosporidium and Giardia are widespread in the environment and major outbreaks have occurred as a result of contaminated drinking water. Cyclospora has significance in the preparation and consumption of fresh food that have not received heat treatment. Toxoplasma gondii, transmission occur through contaminated water, unpasteurised milk and also the consumption of raw meat, which has been regarded as a major route of transmission to humans .These parasitic protozoa do not multiply in foods, but they may survive in or on moist foods for months especially in cool and damp environment. Their ecology makes control of these parasites difficult. Transmission, clinical manifestations, outbreaks, public health surveillance and control measures that are used for those diseases will be reviewed in this article.
This experiment aimed to determine microbial spoilage and lipid and protein oxidation during aerobic refrigerated (4°C) storage of rabbit meat. Forty male New Zealand white rabbits were slaughtered according to the Halal slaughter procedure. The hind limbs were used for microbial analysis while the Longissimus lumborum m. was used for determination of lipid and protein oxidation. Bacterial counts generally increased with aging time and the limit for fresh meat (10(8)cfu/g) was reached at d 7 postmortem. Significant differences in malondialdehyde content were observed after 3d of storage. The thiol concentration significantly decreased with increase in aging time. The band intensities of myosin heavy chain and troponin T significantly reduced with increased refrigerated storage while actin remained relatively stable. This study thus proposes protein oxidation as a potential deteriorative change in refrigerated rabbit meat along with microbial spoilage and lipid oxidation.
The beef industry worldwide is showing a trend towards increased cutting pace aimed at higher profits. However, prior research in the duck meat industry suggested that a higher cutting pace reduced quality and yield, leading to losses. This study aimed to test this hypothesis by investigating the effects of varying beef-cutting paces on yield, quality and economy. A field experiment was conducted on six workers cutting beef fillet, sirloin and entrecôte. Three types of paces were sequentially tested: Baseline (i.e., status quo), 'Quantity focus' (i.e., pace required to maximise quantity) and 'Quality focus' (i.e., pace required to minimise errors). The results showed a significant drop in yield, increased rate of quality deficiency and economic losses with the change to 'Quantity focus' (from Baseline and 'Quality focus') for all meat types. Workers supported these results and also added health problems to the list. The results confirmed that an increased cutting pace is unprofitable.
The study assessed the effect of conscious halal slaughter and slaughter following minimal anesthesia on bleeding efficiency of goats and keeping quality of goat meat. Ten Boer cross bucks were divided into two groups and subjected to either halal slaughter without stunning (HS) or minimal anesthesia prior to slaughter (AS). The blood lost during exsanguination was measured. Residual blood was further quantified by determination of hemoglobin and myoglobin content in longissimus lumborum muscle. Storage stability of the meat was evaluated by microbiological analysis and lipid oxidation. Blood loss at exsanguination, residual hemoglobin and lipid oxidation were not significantly different (p>0.05) between HS and AS. Lactic acid bacteria was the only microbe that was significantly elevated after 24h of storage at 4°C in the AS group. In conclusion, slaughtering goats under minimal anesthesia or fully conscious did not affect bleeding efficiency and keeping quality of goat meat.
In the recent years, Muslims have become increasingly concerned about the meat they eat. Proper product description is very crucial for consumers to make informed choices and to ensure fair trade, particularly in the ever growing halal food market. Globally, Muslim consumers are concerned about a number of issues concerning meat and meat products such as pork substitution, undeclared blood plasma, use of prohibited ingredients, pork intestine casings and non-halal methods of slaughter. Analytical techniques which are appropriate and specific have been developed to deal with particular issues. The most suitable technique for any particular sample is often determined by the nature of the sample itself. This paper sets out to identify what makes meat halal, highlight the halal authenticity issues that occur in meat and meat products and provide an overview of the possible analytical methods for halal authentication of meat and meat products.
The volatile compounds of pork, other meats and meat products were studied using an electronic nose and gas chromatography mass spectrometer with headspace analyzer (GCMS-HS) for halal verification. The zNose™ was successfully employed for identification and differentiation of pork and pork sausages from beef, mutton and chicken meats and sausages which were achieved using a visual odor pattern called VaporPrint™, derived from the frequency of the surface acoustic wave (SAW) detector of the electronic nose. GCMS-HS was employed to separate and analyze the headspace gasses from samples into peaks corresponding to individual compounds for the purpose of identification. Principal component analysis (PCA) was applied for data interpretation. Analysis by PCA was able to cluster and discriminate pork from other types of meats and sausages. It was shown that PCA could provide a good separation of the samples with 67% of the total variance accounted by PC1.
Thirty-two male goats were randomly assigned to four dietary treatments namely, basal diet 70% concentrate and 30% oil palm fronds (control, CN), CN + 400 mg/kg vitamin E (VE), 0.5% turmeric (TU) or 0.5% Anderographis paniculata (AP). After 100 days of feeding, the goats were slaughtered and longissimus dorsi (LD) muscle was sampled. The muscle was vacuum-packaged and conditioned for 0, 7 and 14 days in a chiller (4 °C). The drip loss of the LD muscle increased (P < 0.05) with aging time. Meat tenderness was improved (p < 0.05) at 14 days aging. All antioxidant supplements improved (P < 0.05) colour of the meat. The TBARS value increased (P < 0.05) at 7 days of aging while the fatty acid composition was not affected by the dietary supplements. It is concluded that TU and AP are potential dietary antioxidant supplements, for the purpose of improving the quality of chevon.
Traditional halal slaughter and other forms of religious slaughter are still an issue of debate. Opposing arguments related to pre-slaughter handling, stress and pain associated with restraint, whether the incision is painful or not, and the onset of unconsciousness have been put forward, but no consensus has been achieved. There is a need to strike a balance between halal bleeding in the light of science and animal welfare. There is a paucity of scientific data with respect to animal welfare, particularly the use of restraining devices, animal handling, and efficient halal bleeding. However, this review found that competent handling of animals, proper use of restraining devices, and the efficient bleeding process that follows halal slaughter maintains meat eating quality. In conclusion, halal bleeding, when carried out in accordance with recommended animal welfare procedures, will not only maintain the quality and wholesomeness of meat but could also potentially reduce suffering and pain. Maintained meat quality increases consumer satisfaction and food safety.
This study assessed the effect of gas stunning which has not been conducted until now in comparison with slaughter without stunning on the welfare and meat quality of rabbits. Eighty male New Zealand White rabbits were divided into two groups of 40 animals and subjected to either halal slaughter without stunning (HS) or gas stunning using 61.4% CO2, 20.3% oxygen and 18.3 % nitrogen (GS). Analysis of the sticking blood revealed that both slaughter procedures caused a substantial increase in the levels of catecholamines, hypercalcemia, hyperglycemia, lactic acidemia and an increase in enzyme activities. The ultimate pH of the Longissimus lumborum muscle did not differ between treatments. GS exhibited higher lightness and cooking loss, and lower glycogen and MFI than HS. This indicates that both GS and HS can be significant stressors although the amount of stress may be below the threshold to negatively affect rabbit meat quality.
The influence of dietary lecithin at doses of 0, 4, 20 or 80 g/kg fed to finisher gilts for six weeks prior to slaughter on growth performance, carcass quality and pork quality was investigated. M. longissimus lumborum (loin) was removed from 36 pig carcasses at 24h post-mortem for Warner-Bratzler shear force, compression, collagen content and colour analyses. Dietary lecithin increased dressing percentage (P=0.009). Pork chewiness and collagen content were decreased by dietary lecithin (P<0.05, respectively), suggesting that improved chewiness may be due to decreased collagen content. However, dietary lecithin had no effect on shear force, cohesiveness or hardness (P>0.05, respectively). Dietary lecithin reduced loin muscle L* values and increased a* values (P<0.05, respectively) but no changes on b* values (P=0.56). The data showed that dietary lecithin improved dressing percentage and resulted in less chewy and less pale pork.
The transformation of an animal into pieces fit for human consumption is a very important operation. Rather than argue about halal slaughter without stunning being inhumane or stunning being controversial from the Islamic point of view, we discuss slaughter, stunning and animal welfare considering both Islamic and animal welfare legislation requirements. With the world Muslim population close to two billion, the provision of halal meat for the Muslim community is important both ethically and economically. However, from the animal welfare standard point of view, a number of issues have been raised about halal slaughter without stunning, particularly, about stressful methods of restraint and the latency of the onset of unconsciousness. This paper sets out to, discuss the methods of stunning that are acceptable by Islamic authorities, highlight the requirements for stunning to be acceptable in Islam and suggest practical ways to improve the humanness of slaughter.
The study was carried out to determine the effect of cooking method on Heterocyclic Aromatic Amines (HAs) concentration in grilled chicken and beef (satay). Six common HAs were investigated: 2-amino-3-methylimidazo[4,5-f]quinolone (IQ), 2amino 3,4dimethylimidazo [4,5f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8 trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8trimethylimidazo [4,5-f]quinoxaline (7,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Chicken and beef satay samples were grilled to medium and well done level of doneness. Charcoal grilled (treatment A), microwave pre-treatment prior to grilling (treatment B), and microwave-deep fried (treatment C) were applied to beef and chicken satay samples. The satay samples which were microwaved prior to grilling (B) showed significantly (p<0.05) lower HAs concentration as compared to those charcoal grilled (A). Both medium and well done cooked beef and chicken satay samples that were microwaved and deep fried (C) as an alternative method to grilling were proven to produce significantly lesser HAs as compared to charcoal-grilled (A) and microwaved prior to grilling (B).
A test for assessing pork adulteration in meatballs, using TaqMan probe real-time polymerase chain reaction, was developed. The assay combined porcine-specific primers and TaqMan probe for the detection of a 109 bp fragment of porcine cytochrome b gene. Specificity test with 10 ng DNA of eleven different species yielded a threshold cycle (Ct) of 15.5 ± 0.20 for the pork and negative results for the others. Analysis of beef meatballs with spiked pork showed the assay can determine 100-0.01% contaminated pork with 102% PCR efficiency, high linear regression (r(2) = 0.994) and ≤ 6% relative errors. Residuals analysis revealed a high precision in all determinations. Random analysis of commercial meatballs from pork, beef, chicken, mutton and goat, yielded a Ct between 15.89 ± 0.16 and 16.37 ± 0.22 from pork meatballs and negative results from the others, showing the suitability of the assay to determine pork in commercial meatballs with a high accuracy and precision.
The present investigation focuses on the textural properties, sensory attributes and color changes of beef frankfurter, beef ham and meat-free sausage produced by different levels of bleached tomato pomace. The texture and color profile were performed using an instrumental texture analyzer and colorimeter. The findings indicated that tomato pomace-added sausages had higher water holding capacity (WHC) compared to that of commercial samples. The frankfurters containing 5 and 7% (w/w) tomato pomace had the highest redness (a*), chroma (C*) and color differences (ΔE) values, while the meat-free sausages containing 7% (w/w) tomato pomace had significant (p<0.05) values for lightness (L*) and yellowness (b*). Furthermore, there were no significant (p>0.05) color differences between beef ham samples (with and without tomato pomace). A significant progression in the textural hardness and chewiness of systems containing tomato pomace was observed as well as higher sensory scores by panelists. According to sensorial evaluations, bleached tomato pomace improved the consumer acceptability and preference.