Beef Homogenates Research Articles

Antioxidant Activity of Egg Yolk Protein Hydrolysates Obtained by Enzymatic and Sub-Critical Water Hydrolysis

Obtaining peptides with antioxidant properties by enzymatic hydrolysis has been widely described; however, the use of non-enzymatic methods to obtain peptides with antioxidant capacities has been poorly investigated. In this study, non-soluble proteins obtained from delipidated egg yolk granules were hydrolyzed with trypsin, and with a non-enzymatic method using sub-critical water hydrolysis under a non-oxidizing (nitrogen) and oxidizing (oxygen) atmosphere. The effect of the sub-critical water hydrolysis on the amino acids’ composition of the hydrolysates was assessed. Furthermore, the antioxidant capacities of the hydrolysates were evaluated using the ABTS•+ scavenging assay, the DPPH radical scavenging activity assay, and by measuring the reducing power of the peptides, the peptides’ ferrous ion chelating capacities, and the antioxidant effect of the peptides on beef homogenates. The hydrolysate obtained by sub-critical water hydrolysis under a nitrogen stream showed similar or better results in the antioxidant tests than those obtained using trypsin hydrolysis, except in the ferrous chelating capacity, where the trypsin hydrolysate showed the best performance. The oxidizing environment promoted by the oxygen in the other sub-critical water hydrolysis method tested produced the peptides with the lowest antioxidant capacities, due to changes in the primary structure of the peptides. These results suggest that the sub-critical water hydrolysis method under a nitrogen stream, in comparison with the enzymatic hydrolysis, is a reliable method to obtain peptides with good antioxidant capacities.

Physicochemical stability of antilisterial proteins from P. polymyxa Kp10 as potential food biopreservative

AbstractListeria monocytogenes has continuously become a significant threat to consumers worldwide. The use of chemical‐derived preservatives that are commonly associated with safety and nutritional issues has prompted the use of natural‐based preservatives as a better alternative. Many bacterial strains including Paenibacillus polymyxa Kp10 have been reported to produce various antimicrobial proteins and compounds that are considered more natural. However, their stability in various physicochemical conditions should be examined before being applied in various types of food. In this study, the stability of four previously identified antilisterial proteins in P. polymyxa Kp10 upon exposure to several physicochemical conditions was examined. More than 80% residual antilisterial activity is conserved upon heat and proteinase K treatment. But, sensitivity to 24 h trypsin digestion has been observed. P1 and P2 proteins (histone‐like DNA binding proteins HU) were sensitive to alkaline pH (pH 10‐12) as compared with other proteins. More than 70% and 97% residual antilisterial activity were recovered after incubation in raw beef homogenates and simulated meat gravy model, respectively. However, the antilisterial activity of most proteins was highly compromised in chicken and salmon meat homogenates, and UHT cow milk. Inoculation of these proteins into Listeria‐contaminated simulated meat gravy showed that all proteins exerted a bactericidal action against L. monocytogenes. P1 and P2 shared almost similar antilisterial activity rates, while P4 was the most potent antilisterial protein. The findings in this study could provide important preliminary data for future applications of these proteins as preservative in food products especially beef‐based meat products.

Quality properties of beef patties manufactured with chestnut powder

This study was investigated the quality properties of beef patty incorporated with chestnut powder. The flesh of chestnut was lyophilized and then pulverized. The chestnut powder was added at a level of 1% (10 g), 2% (20 g), and 3% (30 g) into beef homogenate consisted of minced beef (600 g), water (100 g), unpolished rice oil (80 g), onion (100 g), garlic (15 g), bread crumb (80 g), egg (15 g), salt (10 g). Beef patties were manufactured without chestnut powder were used as a control. The pH of raw beef homogenate was not affected by the addition of chestnut powder. Cooking loss was gradually reduced with the increase of chestnut powder (p<0.05) and the texture of beef patty was softened with increasing chestnut powder content (p<0.05). The addition of chestnut powder significantly reduced the lightness, redness, and yellowness of beef patty. The malondialdehyde content was significantly increased in beef patty with 2% of chestnut powder, but there was no dose-dependence. Therefore, the addition of chestnut powder to beef patties did not have an effect on improving the oxidation stability but improved water holding capacity of the beef patties.

Detection of pathogenic bacteria in large volume food samples using an enzyme-linked immunoelectrochemical biosensor

Increased speed and sensitivity of testing are always desired for the detection of pathogens in foods. Presented a test sample with low microbial analyte concentration, it is an advantage to analyze as much volume as possible of the sample to attain the best limit of detection (LOD). Therefore, a rapid screening method using a novel flow-through immunoelectrochemical biosensor was developed for the detection of pathogenic bacteria (E. coli O157:H7 and Salmonella) in food (ground beef). As the working electrode employed was comprised of a porous, antibody-coated graphite felt electrode that served as both a biorecognition-element coated solid support for capture of targeted pathogens as well as a signal transducer, high volumes of aqueous sample could be rapidly exposed to the solid support via gravity flow. Flow rates as high as 16.7 mL/min and 12.3 mL/min could be achieved for bacterial samples in buffer and 1:4 ground meat (beef) homogenate, respectively, with no significant effect on LOD. Fastest flow rates for beef homogenate, without clogging of the porous electrode as well as reduction in apparent electrochemical interference, was realized with a tandem combination of sample pretreatment strategies that included filtration with glass wool and graphite felt as well as continuous flow centrifugation. The LOD for 10,000 E. coli O157 cells in 5, 60, and 1000 mL of buffer was 2000, 170, and 10 cells/mL, respectively in a total assay time of 3 h whereas the LOD for E. coli O157 was 400 cells/mL in 1:4 beef homogenate.

In vitro Antioxidant Capabilities and Vitamin Levels in Beef, Chicken and Fish Homogenates

In this modern era of functional food research, there are possibilities that we could eat not only to derive nutritional values but also to get well. In this study, the antioxidant and vitamin level in fish, beef and chicken homogenates were determined using various assays. The results showed that vitamin E levels in fish homogenate (34.47 ± 1.04 µg/dL) were significantly high (p<0.05) compared with chicken homogenate (29.55 ± 4.84 µg\dL), and beef homogenate (19.16 ± 0.96 µg/dL). Also the vitamin C levels in the beef homogenates (51.12 ± 3.74) was significantly higher (p<0.05) compared to the chicken homogenates (28.60 ± 2.42 mg/dL) and fish homogenates (26.39 ± 1.63). However, there was no significant difference (p>0.05) in the vitamin C levels between the fish and chicken homogenates. The fish and chicken homogenate showed significant dose-dependent DPPH radical inhibiting capacities, inhibiting 17.55 ± 3.71% and 16.61 ± 2.22% of DPPH at a concentration of 15 mg/mL compared to the meat homogenate which inhibited 11.68 ± 1.78% at the same concentration. The IC50 of superoxide anion radical inhibition was found to be significantly lower (p<0.05) for the chicken and meat homogenate compared to the fish homogenate. From this experiment it can be postulated that fish and beef have a higher antioxidant levels compared to chicken and could be better source of functional foods.

Membrane Insertion for the Detection of Lipopolysaccharides: Exploring the Dynamics of Amphiphile-in-Lipid Assays.

Shiga toxin-producing Escherichia coli is an important cause of foodborne illness, with cases attributable to beef, fresh produce and other sources. Many serotypes of the pathogen cause disease, and differentiating one serotype from another requires specific identification of the O antigen located on the lipopolysaccharide (LPS) molecule. The amphiphilic structure of LPS poses a challenge when using classical detection methods, which do not take into account its lipoglycan biochemistry. Typically, detection of LPS requires heat or chemical treatment of samples and relies on bioactivity assays for the conserved lipid A portion of the molecule. Our goal was to develop assays to facilitate the direct and discriminative detection of the entire LPS molecule and its O antigen in complex matrices using minimal sample processing. To perform serogroup identification of LPS, we used a method called membrane insertion on a waveguide biosensor, and tested three serogroups of LPS. The membrane insertion technique allows for the hydrophobic association of LPS with a lipid bilayer, where the exposed O antigen can be targeted for specific detection. Samples of beef lysate were spiked with LPS to perform O antigen specific detection of LPS from E. coli O157. To validate assay performance, we evaluated the biophysical interactions of LPS with lipid bilayers both in- and outside of a flow cell using fluorescence microscopy and fluorescently doped lipids. Our results indicate that membrane insertion allows for the qualitative and reliable identification of amphiphilic LPS in complex samples like beef homogenates. We also demonstrated that LPS-induced hole formation does not occur under the conditions of the membrane insertion assays. Together, these findings describe for the first time the serogroup-specific detection of amphiphilic LPS in complex samples using a membrane insertion assay, and highlight the importance of LPS molecular conformations in detection architectures.

Effects of Plant-Derived Extracts, Other Antimicrobials, and Their Combinations against Escherichia coli O157:H7 in Beef Systems

The antimicrobial effects of thyme oil (TO), grapefruit seed extract (GSE), and basil essential oil, alone or in combination with cetylpyridinium chloride (CPC), sodium diacetate, or lactic acid, were evaluated against Escherichia coli O157:H7 in a moisture-enhanced beef model system. The model system was composed of a nonsterile beef homogenate to which NaCl (0.5%) and sodium tripolyphosphate (0.25%) were added, together with the tested antimicrobial ingredients. Beef homogenate treatments were inoculated (ca. 3 log CFU/ml) with rifampin-resistant E. coli O157:H7 (eight-strain mixture) and incubated at 15°C (48 h). The most effective individual treatments were TO (0.25 or 0.5%) and GSE (0.5 or 1.0%), which immediately reduced (P < 0.05) pathogen levels by ≥3.4 log CFU/ml. Additionally, CPC (0.04%) reduced initial E. coli O157:H7 counts by 2.7 log CFU/ml. Most combinations of the tested plant-derived extracts with CPC (0.02 or 0.04%) and sodium diacetate (0.25%) had an additive effect with respect to antibacterial activity. In a second study, antimicrobial interventions were evaluated for their efficacy in reducing surface contamination of E. coli O157:H7 on beef cuts and to determine the effect of these surface treatments on subsequent internalization of the pathogen during blade tenderization. Beef cuts (10 by 8 by 3.5 cm) were inoculated (ca. 4 log CFU/g) on one side with the rifampin-resistant E. coli O157:H7 strain mixture and were then spray treated (20 lb/in2, 10 s) with water, GSE (5 and 10%), lactic acid (5%), or CPC (5%). Untreated (control) and spray-treated surfaces were then subjected to double-pass blade tenderization. Surface contamination (4.4 log CFU/g) of E. coli O157:H7 was reduced (P < 0.05) to 3.4 (5% CPC) to 4.1 (water or 5% GSE) log CFU/g following spray treatment. The highest and lowest transfer rates of pathogen cells from the surface to deeper tissues of blade-tenderized sections were obtained in the untreated control and CPC-treated samples, respectively.

Radiofrequency pasteurization of inoculated ground beef homogenate

Inactivation of nonpathogenic Escherichia coli in ground beef homogenate using radio-frequency (RF) heating both individually and in combination with antimicrobial treatments was investigated. Beef homogenate was prepared in phosphate buffer (pH 5.8). Inoculated beef homogenate was heated in an RF oven without antimicrobials to end-point temperatures of 50 °C resulting in 0.84 log reductions and 55 °C resulting in 0.94 log reductions. Adding antimicrobials-potassium, sodium, and ammonium bicarbonates (0.5 and 1.5%); citric acid (0.5%); potassium lactate (2.5%); and a blend of potassium bicarbonate (1.5%) and citric acid (0.5%) to the beef homogenates before RF heating did not inactivate E. coli. E. coli inactivation was also not affected in beef homogenates containing antimicrobials when heated to 50 °C in the RF oven. Heating to 55 °C did reduce E. coli more than 5 log (CFU/mL) reduction of E. coli in homogenates containing 2.5% potassium bicarbonate, 0.5% citric acid, and blends of citric acid and potassium bicarbonate at varying concentrations (0.5% citric acid + 0.5% Citric acid and 1.5% bicarbonate). This study offers scope and potential for the application of RF assisted pasteurization with antimicrobial systems as interventions to enhance the overall ground beef safety. The findings of this study should provide potential to explore industrial scale RF pasteurization of beef and other meat products while ensuring that the quality characteristics are maintained.

Effect of radio-frequency on heating characteristics of beef homogenate blends

The heating characteristics of different lean-to-fat ratios in ground beef (90/10, 85/15, 80/20, 73/27) was investigated using radio-frequency (RF) heating of ground beef homogenates. A homogenate model system was prepared with ground beef in phosphate buffer (pH 6.0). Homogenate blends were packaged in vacuum bags, immersed in pre-heated water at 10, 25 and 50 °C, and heated in the RF equipment to a target temperature of 60 °C. Beef homogenate blends with more lean and less fat (90/10 and 85/15) heated more rapidly, reaching the target temperature faster than the higher fat composition blends. The RF heating rates of the beef homogenate blends varied with water temperature; higher temperature resulted in rapid RF heating. The RF heating rate at 50 °C was the most rapid in heating all homogenate blends. The instrumental color characteristics for RF heated homogenate blends exhibited lower L* and a* values than uncooked homogenate blends. RF heating resulted in reduced redness and more oxidation of myoglobin (metmyoglobin formation) and lesser oxy- and deoxy-myoglobin redox forms in all beef homogenate blends independent of the initial water temperature. The results present scope to explore short time heating processes which will minimize quality deterioration in RF heated meat products.

Fractionation of Protein Hydrolysates of Fish and Chicken Using Membrane Ultrafiltration: Investigation of Antioxidant Activity

In this work, chicken and fish peptides were obtained using the proteolytic enzymes α-Chymotrypsin and Flavourzyme. The muscle was hydrolyzed for 4 h, and the resulting peptides were evaluated. Hydrolysates were produced from Argentine croaker (Umbrina canosai) with a degree of hydrolysis (DH) of 25.9 and 27.6% and from chicken (Gallus domesticus) with DH of 17.8 and 20.6% for Flavourzyme and α-Chymotrypsin, respectively. Membrane ultrafiltration was used to separate fish and chicken hydrolysates from Flavourzyme and α-Chymotrypsin based on molecular weight cutoff of >1,000, <1,000 and >500, and <500 Da, to produce fractions (F1,000, F1,000-500, and F500) with antioxidant activity. Fish hydrolysates produced with Flavourzyme (FHF) and α-Chymotrypsin showed 60.8 and 50.9% of peptides with a molecular weight of <3 kDa in its composition, respectively. To chicken hydrolysates produced with Flavourzyme and α-Chymotrypsin (CHC) was observed 83 and 92.4% of peptides with a molecular weight of <3 kDa. The fraction that showed, in general, higher antioxidant potential was F1,000 from FHF. When added 40 mg/mL of FHF and CHC, 93 and 80% of lipid oxidation in ground beef homogenates was inhibited, respectively. The composition of amino acids indicated higher amino acids hydrophobic content and amino acids containing sulfuric residues for FHF, which showed antioxidant potential.

Redox stability of myoglobin influenced by inorganic redox iron forms and metabolic substrates in a beef homogenate system

Redox stability of myoglobin influenced by inorganic redox iron forms and metabolic substrates in a beef homogenate system

Lactic acid resistance of Shiga toxin-producing Escherichia coli and multidrug-resistant and susceptible Salmonella Typhimurium and Salmonella Newport in meat homogenate

This study compared lactic acid resistance of individual strains of wild-type and rifampicin-resistant non-O157 Shiga toxin-producing Escherichia coli (STEC) and of susceptible and multidrug-resistant (MDR) and/or MDR with acquired ampC gene (MDR-AmpC) Salmonella against E. coli O157:H7. After inoculation of sterile 10% beef homogenate, lactic acid was added to a target concentration of 5%. Before acid addition (control), after acid addition (within 2 s, i.e. time-0), and 2, 4, 6 and 8 min after addition of acid, aliquots were removed, neutralized, and analyzed for survivors. Of wild-type and of rifampicin-resistant non-O157 STEC strains, irrespective of serogroup, 85.7% (30 out of 35 strains) and 82.9% (29 out of 35 strains), respectively, reached the detection limit within 0–6 min. Of Salmonella strains, 87.9% (29 out of 33 isolates) reached the detection limit within 0–4 min, irrespective of antibiotic resistance phenotype. Analysis of non-log-linear microbial survivor curves indicated that non-O157 STEC serogroups and MDR and susceptible Salmonella strains required less time for 4D-reduction compared to E. coli O157:H7. Overall, for nearly all strains and time intervals, individual strains of wild-type and rifampicin-resistant non-O157 STEC and Salmonella were less (P < 0.05) acid tolerant than E. coli O157:H7.

The effects of high salt and low pH on the water-holding of meat

The study investigated the water-holding (WH) in meat in the pH–NaCl (ionic strength) combinations that prevail in dry sausages during fermentation and drying. WH in raw beef homogenates, with 230% added water, was determined by centrifugation at pH values of 5.47–4.60, and ionic strengths (μ) 0.50–1.50. The minimum WH in relation to pH was at pH 4.8, but at higher pH values, the WH optimum was at 1.0–1.5μ; at lower pH-values (<5.0) the optimum was more pronounced at 1.0μ. The WH reducing effect by pH decrease was stronger than the effect of μ. At lower pH values, the relative effect of μ on WH was higher compared to that of pH than at higher pH values. The pH–salt combinations prevailing in fermented sausage in the beginning of the ripening produced a high WH, which decreased, first with pH decrease and then in the last period of ripening mainly due to the increase of ionic strength.

New Zealand green-lipped mussels (Perna canaliculus) enhance non-haem iron absorptionin vitro

Fe bioavailability can be manipulated by the nutritional composition of a meal. Ascorbic acid and unidentified components of meat, fish and poultry, but particularly beef, all appear to enhance the absorption of non-haem Fe. The aim of the present study is to identify whether extracts of green-lipped mussels (GLM; Perna canaliculus) enhance non-haem Fe absorption in Caco-2 cells and to compare the effect with that of beef. Raw GLM and raw beef homogenates were digested in vitro with pepsin at pH 2, and pancreatin and bile salts at pH 7. Tracer ⁵⁵Fe was used to measure cellular Fe uptake. Ascorbic acid was used as a positive control and egg albumin, exposed to the same in vitro digestion process, was used as a negative control. Caco-2 cell monolayers were incubated with treatments for 60 min. All values were standardised per μg of GLM, egg albumin, beef or ascorbic acid. The results showed that ascorbic acid enhanced non-haem Fe absorption to the highest degree. Beef and GLM digestates both significantly enhanced Fe absorption compared with egg albumin. In conclusion, GLM digestate significantly enhances non-haem Fe uptake in Caco-2 cells with a similar magnitude to that of beef.

Rapid detection and identification of bacterial pathogens by using an ATP bioluminescence immunoassay.

Rapid identification of viable bacterial contaminants in food products is important because of their potential to cause disease. This study examined a method for microbial detection by using a combined ATP bioluminescence immunoassay. Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium were selected as target organisms because of their implication in foodborne illness. Various matrices containing the target cells were examined, including ground beef homogenate, apple juice, milk, and phosphate-buffered saline. Specific antibodies were immobilized on the surface of 96-well plates, and then the sample matrices containing target cells in the wells were incubated. Sample matrix (no cells) was used to establish background. The plates were washed, and the wells were incubated with BacTiter-Glo reagent in Mueller-Hinton II broth. Bioluminescent output was measured with the GloMax 96 luminometer. Signal-to-noise ratios were calculated, resulting in a limit of detection of 10(4) CFU/ml for both E. coli O157:H7 and Salmonella Typhimurium. The limit of detection for both species was not affected by the presence of nontarget cells. The various sample matrices did not affect signal-to-noise ratios when E. coli O157:H7 was the target. A weak matrix effect was observed when Salmonella Typhimurium was the target. A strong linear correlation was observed between the number of cells and luminescent output over 4 orders of magnitude for both species. This method provides a means of simultaneously detecting and identifying viable pathogens in complex matrices, and could have wider application in food microbiology.

Development and Use of a Chromogenic Macroarray System for the Detection ofStaphylococcus aureuswith Enterotoxin A, B, C, D, E, and G Genes in Food and Milk Samples

Abstract Staphylococcus aureus is one of the major pathogens that can cause staphylococcal infection and food poisoning. There are five major classical types of staphylococcal enterotoxins (SEs): SEA, SEB, SEC, SED, and SEE, as well as new SEs or SE-like superantigens (SAgs), such as SEG to SEU. Since many S. aureus strains harbor more than one SE gene and identification of SEs involved in food poisoning cases is time consuming, we developed a chromogenic macroarray method that allows convenient and simultaneous detection of classical SE genes and a new SE gene (seg), which is phylogenetically highly related to seb and sec. Two sets of degenerated primers labeled with biotin were used to co-amplify all SE genes in S. aureus strains through the polymerase chain reaction (PCR). Afterwards, these biotin-labeled PCR products were hybridized with SE gene-specific probes spotted on the nitrocellulose membrane. When this macroarray was used to detect enterotoxingenic S. aureus in milk or beef homogenate containing 10(0)-10(4) target cells per milliliter or gram of the sample, all six enterotoxin genes could be identified after a 12-hour enrichment step. This macroarray offers clinical and food inspection laboratories a rapid and economical visual method to detect common enterotoxigenic S. aureus strains.

Casein peptides with inhibitory activity on lipid oxidation in beef homogenates and mechanically deboned poultry meat

Bioactive peptides obtained by enzymatic hydrolysis of casein may have antioxidant activity. In this work, casein peptides were obtained using the proteolytic enzymes Alcalase and Flavourzyme. Casein was hydrolyzed for 4 h at 50 °C and pH 8, and the resulting peptides were analyzed. The enzymatic hydrolysis with Flavourzyme resulted in higher concentration of soluble protein and free amino acids, and produced peptides with lower molecular mass than those obtained with Alcalase, as observed by gel permeation chromatography and polyacrylamide gel electrophoresis. Casein peptides obtained with Flavourzyme also exhibited greater antioxidant capacity using the ABTS radical method. Casein peptides (20 mg ml−1) effectively inhibited lipid peroxidation in ground beef homogenates and mechanically deboned poultry meat. Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavor formation in meat products and increasing shelf life.

Optimization of emulsion characteristics of beef, chicken and turkey meat mixtures in model system using mixture design

Emulsion pH (pHe), emulsion capacity (EC), emulsion stability (ES), emulsion density (ED) and apparent yield stress of emulsion (raw emulsion, AYSe) and emulsion gel (cooked emulsion, AYSg) of beef, chicken and turkey meats and their mixtures were studied using a model system. Turkey meat homogenate was found to have higher protein concentration than chicken or beef homogenates. The highest pHe, EC and ES values and the lowest ED and AYSe values were found in chicken meat. However, the highest AYSg value was found in chicken–turkey meat mixture. Generally, the increasing amount of chicken meat in mixtures increased EC and ES, and decreased ED and AYSe values. Also, chicken–turkey meat mixtures had lower ES values than the mixtures containing only chicken or only turkey meat. With beef, the addition of chicken and turkey meats improved emulsion characteristics significantly. Optimum levels of beef, chicken and turkey meats were found to be 0–23%, 9–30% and 53–91% respectively.

The effect of phytic acid on oxidative stability of raw and cooked meat

The effects of phytic acid addition (0.1, 1 and 5 mM) to pork and beef homogenates on TBARS and metmyoglobin levels in raw meat, and TBARS and heme iron contents in cooked meat during 3 days of storage at 4 °C were investigated. Also, the role of inositol as a potential synergist of IP 6 (phytic acid) was examined. IP 6 effectively decreased the TBARS accumulation in raw and cooked meat homogenates. The metmyoglobin formation was inhibited in raw beef by phytic acid in a dose-dependent manner. The effect of IP 6 was more pronounced in cooked meat than in raw and in cooked beef homogenates more than pork. Inositol did not enhance antioxidant action of phytic acid in minced meat.

Detection of beef contaminated by bovine central nervous system tissue by enzyme immunoassay

To study influencing factors of detection of bovine central nervous system (CNS) tissue contaminated beef by enzyme immunoassay (EIA), and the method was applied to the detection of imported beef and domestic beef of China. Raw beef homogenates containing different concentrations of raw CNS tissue and the same samples which were heated were detected after different time by RIDASCREEN(r) Risk Material 10/5 and RIDASCREEN(r) Probennahme- zubehor Sampling tools kits. PBS suspension and sample dilution buffer (SDB) suspension of bovine brain tissue with the same concentration of the standard were detected. Beef from USA and domestic market of China were then detected by the kits. The kits could detect both raw and heated CNS tissue in the products with high sensitivity. The absorbance values (AV) increased with the concentrations of CNS in samples. Heating and increasing of time could decrease the absorbance values of the samples which contain CNS tissue. The AV of the PBS suspension of bovine brain tissue was higher than the SDB suspension and the AV of both were higher than the AV of standard of the same concentration. No CNS tissue was detected from all imported beef. No CNS tissue was detected in all samples from domestic market of China except for foxtail. The EIA method has high sensitivity for detection of bovine CNS tissue contaminated beef with the glial fibrillary acidic protein (GFAP) as accurate target substance. Heating and increasing of time can lead to decreasing of the AV of samples. Improper slaughter process can lead to contamination of bovine products by bovine CNS tissue.