Control of Bacillus cereus Spores and Spoilage Microflora in Sous Vide Chicken Breast

Safety of sous vide chicken breast with respect to Bacillus cereus and effect of processing parameters on natural microflora were evaluated. B. cereus, a facultatively anaerobic sporeformer, may cause foodborne illness and has been isolated from poultry. Product was inoculated and processed to 77°C or 94°C. Populations were reduced by 0.5- to 1.0-log and by 3-log in products heated to 77°C and 94°C, respectively. Spores germinated within 1 day at 10°C yet detectable changes in populations were not evident through 28 days storage. Lactate did not influence B. cereus populations or spore germination. Natural microflora was reduced by processing and remained low through 28 days storage at 4°C and 10°C.     

Effect of skin addition on the technological properties of comminuted chicken meat emulsions

Possibility of using skin supplement as collagen raw material (substituting leg muscles) in highly comminuted sausages made from breast muscles was investigated. It was found that 5% skin added to the comminuted breast muscles resulted in the collagen content equal to that obtained with 40% leg muscles. Addition of 5% skin to the breast muscles decreases emulsifying capacity of protein extracts but increases thermal stability, and changes the flow curve of meat emulsions more than the addition of dark muscles. The skin used instead of leg muscles does not change sausage binding (shear force) and overall sensory value, but reduces water-holding capacity and palat-ability of sausages.     

Bacteriocins Applied to Food Packaging Materials to Inhibit Listeria monocytogenes on Meats

Bacteriocins in powders were produced from milk-based media and applied to food packaging films. Nisin and pediocin “powders” were retained in casings during dialysis. Antilisterial casings were prepared by internal coating with pediocin. Antilisterial activity applied in powdered form was retained during processing and retained on contact food packaging surfaces. Pediocin powder was applied to plastic packaging bags at 7.75 μg/cm². Meats and poultry samples were inoculated with Listeria monocytogenes. The bags coated with pediocin powder completely inhibited growth of inoculated L. monocytogenes through 12 wk storage at 4°C. Applying bacteriocins to food packaging films is an effective approach to reduce L. monocytogenes contamination in meats and poultry.     

Textural Properties of Chicken Frankfurters with Added Collagen Fibers

Chicken frankfurters made with 0, 2, 4, 6, 8% added collagen fibers and 10, 15, 20, 25, 30% added water were evaluated for textural differences using a torsion test and sensory texture profile analysis. Frankfurters with high amounts of added water and low amounts of collagen fibers had lower shear stress values. Sensory analysis indicated that both collagen fibers and added water had significant influences (P<0.05) on hardness, springiness and juiciness. The addition of collagen fibers resulted in harder, springier, and less juicy frankfurters. Added water resulted in softer, less springy and juicier frankfurters. Response surface methodology demonstrated that for 2% added collagen, the optimum added water was ～20%.     

Temperature and NaCl Affect Growth and Survival of Escherichia coli 0157:H7 in Poultry-Based and Laboratory Media

In tryptic soy broth (TSB) and a poultry extract broth (PB) with 0 to 10% (w/v) NaCl incubated at 37°C, growth of E. coli 0157:H7 was inhibited at 28% NaCl whereas at 10°C, growth was inhibited at 24% NaCl in TSB and at 26% NaCl in PB. The bacterium did not grow at 4°C. Increased NaCl-sensitivity observed at 10°C was a bacteriostatic effect that was ineffective with increasing incubation temperature. At 10°C, E. coli 0157:H7 was more salt-tolerant in PB than in TSB, although PB growth rates were lower. Findings suggest that PB may be a more suitable medium for testing E. coli 0157:H7 in poultry products. Cells of E. coli 0157:H7 that were exposed to refrigeration (4°C) and/or NaCl for 24 days did not grow on MacConkey agar with 1% sorbitol.     

不同来源肠炎沙门菌毒力基因特征分析

目的研究石家庄地区不同来源的肠炎沙门菌毒力基因携带情况的差异及特点。方法收集石家庄地区早市生禽销售点、生禽屠宰场及食物中毒标本中分离出的肠炎沙门菌124株,对其中8种毒力基因(invA、sopE、agfA、spvR、hilA、stn、pefA、shdA)进行聚合酶链式反应(PCR)检测。结果肠炎沙门菌具有不同的毒力基因谱型,8种毒力基因在不同来源的肠炎沙门菌中均有检出,其中毒力基因invA、sopE、stn、hilA、spvR、pefA在食物中毒分离株中的携带率高,均在94%以上。食物中毒分离株与早市生禽销售点分离株的8种毒力基因携带率差异无统计学意义(P0.05),而生禽屠宰场分离株与食物中毒和早市生禽销售点分离株之间差异有统计学意义(P0.05)。结论石家庄地区早市生禽销售点检出的肠炎沙门菌中易致病的高风险株较多,应加强对生禽的卫生监督与防控。     

Annual dose rate for Qena governorate population due to consume the animal products

In this work, the natural radionuclide concentrations of the 226Ra, 228Ra, 232Th and 40K were estimated from samples of cattle and poultry fodder, South Valley University farms and Qena Governorate farm, Qena, Upper Egypt. The radionuclide concentrations and annual consumption rate of twenty-nine animal fodders were analyzed using low-level γ-spectrometer, including a mixture fodder, silage, hay, rice straw, and poultry fodder. The irradiation risk of human health was assessed due to indirect ingestion of the beef, milk, poultry and egg, the annual effective dose of the radionuclides for the local consumer was 2.7, 14, 0.1, and 0.14 μSv·y–1, respectively.     

Simultaneous immunochemical detection of four banned antibiotic growth promoters in raw and cooked poultry tissue

Spiramycin, tylosin, bacitracin and virginiamycin are among a group of antibiotic growth promoters that have been banned in the European Union since the 1999 Council. This was due to concerns over the development of resistant bacteria emerging between humans and animals with the threat of antibiotics no longer being able to be used effectively to treat human infections. A sensitive and fast immunochemical method is presented for the determination of these four antibiotic growth promoters simultaneously in poultry tissue. The method employs methanol extraction followed by sample clean-up by solid-phase extraction (SPE) with determination by enzyme-linked immunoabsorbant assay (ELISA). The limit of detection (LOD) was less than 1 ng g^?1 and the detection capability (CCβ) was 3 ng g^?1 or less for all four antibiotic growth promoters. Validation was completed with both raw and cooked chicken, therefore either matrix could be used for the monitoring of these banned drugs. In a feeding trial no residues of either bacitracin or virginiamycin were found in medicated birds even without a withdrawal period. In the case of tylosin and spiramycin much higher residues level were detected immunochemically than was the case by mass spectrometry.