Building Teaching And Research Capacity At The Food Science Cluster Of Western Kentucky University To Control Salmonella In Chicken Products

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Teaching Objectives
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Objective 1. Develop a novel poultry technology class at WKU Food Science Cluster A poultry technology class will include three hours lectures and one hour bench-top laboratory emphasizing the principles of operation and study of poultry processing. The objective of this course is to provide students with a comprehensive understanding of fundamentals and practical applications of modern poultry processing and working knowledge of processing of poultry meat, manufacturing of different commercial poultry products, regulatory issues related to processing and shell egg processing. In the lecture part of this course, mechanical separation of poultry meat, marinating technology, smoking and curing technology, and sausage manufacture will be covered as four course lectures/chapters. In the lab portion, the processing of chicken meat, including marination, and manufacturing of chicken sausage and cooking processing, its related spoilage and pathogenic bacteria testing, and cultivation/numeration of BSL-2 pathogenic bacteria will be included in three poultry technology lab sections. The syllabus and course outline will be developed approximately 6-12 months after receiving funding.
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Objective 2. Purchasing of food safety/quality equipment and recruit undergraduates to conduct research projects of control Salmonella during chicken products processingSubtitle 1. Purchasing of food safety/quality equipment The following equipment will be purchased, installed and tested.electronic sprayer and installation-80oC freezerincubation chamber bench-top centrifugecommercial display casecirculated water bathcommercial size meat grounderfat and moisture analyzerstandard kitchen ovenSubtitle 2. Recruit undergraduates to conduct research projects of control Salmonella during chicken products processingDuring the grant period, we are planning to recruit 10-15 high ability and motivated biology or chemistry major undergraduate students into conducting research tasks focusing on reduction of Salmonella (PD, Dr. Shen) and chicken quality control (Co-PD Ms. Norris) during chicken meat processing. The students will be trained to complete lab research objectives, data collection and analysis, contribute to conference abstracts and peer-review journal manuscripts' writing, and food science conferences poster or oral presentation preparation.
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Research Objectives
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Objective 1. Compare the efficacy of electrostatic spraying versus conventional spraying with chlorinated water on commercially processed chicken wings for reducing Salmonella spp Salmonella Typhimurium and Salmonella Enteritidis (poultry processing isolation, obtained by USDA-ARS, College Station, TX) strains will be maintained in brain heart infusion broth with 20% glycerol and stored at -80°C. Prior to an experiment, the stock cultures will be grown up in 10 mL of TSB and incubated at 37°C for 24 h.Fresh chicken wings will be obtained from a local poultry processor Perdue Farms, Hartford, KY. Batches of 5 chicken wings will be transferred to a 2.5-gal Hefty OneZip bags. The bagged chicken wings will be inoculated by adding 10 ml of Salmonella inoculum with 90 ml of buffered peption warer into the bag, and shaken for 15 min to make the wings surfaces equally inoculated of approximately 5 log CFU/cm2. After inoculation, chicken wings will sit for 15 min on foil covered trays under biohazard hood to dry. The inoculated procedures are used to simulate the pathogen cross contamination among chicken wings on commercial packaging bags.Inoculated chicken wings will be transferred into a biohazard hood, placed on sterile grill wire netting, and sprayed from a distance of 15 or 30 cm at approximately 23oC by an electrostatic sprayer or a conventional sprayer containing chlorinated water (free chlorine: 0, 10, or 50 ppm, pH 6.8, 5 or 23oC) for 30 s, 60 s, or 120 s, turned over, sprayed for another 30 s, 60 s, or 120 s, and then air dried for 1 min. Two sprayed chicken wings in each treatment will be individually vacuum-packaged and stored at 4oC in simulated commercial retail display case for up to 21 days. On day 0, 1, 3, 7, 14, and 21, sprayed chicken wings will be individually placed in a Whirl-Pak filter bag with 100 ml of maximum recovery diluent (0.85% NaCl and 0.1% peptone) and shaken vigorously in a rotating mechanical shaker for 2 min. Serial 10-fold dilutions of each sample in 0.1% buffered peptone water will be surface plated onto Aerobic Plate Counts (APC) , E. coli/Coliform petrifilms, and XLT-4 for enumeration of total bacterial populations and Salmonella spp., respectively. Objective color measurements will be taken with a HunterLab Miniscan EZ with full spectral data being obtained as well as L* (lightness), a* (redness), and b* (yellowness). The experiment will be performed twice, and each time will include three individual samples per treatment. The microbial, physical and chemical data will be analyzed using Mixed Procedure of SAS.
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Objective 2. Evaluate the thermal inactivation activity of Salmonella in commercial marinated chicken sausage without/with antimicrobials Fresh raw chicken meat will be purchased from a local chicken establishment (Perdue Farms). The 1-kg of chicken meat will be inoculated with 5-6 log CFU/g of Salmonella spp. The meat and inoculum will be thoroughly mixed for 2 minutes using a bowl lift stand mixer (Kitchen aid). The inoculated chicken will be mixed for an additional 2 minutes with tomato puree-based (A1® Classic Marinade), lemon-based (Lawry's® Lemon Pepper) or soy sauce-based (Kikkoman® Teriyaki marinade) commercial marinades, or lemon juice (Kroger®), soy sauce (Kikkoman®) or tomato juice (Campbell's®) domestic marinades. The marinated samples will be extruded through sausage stuffer into peelable cellulose casings and then will undergo aerobic storage at 4oC for 15 days in air-permeable films to simulate retail display packaging. After storage of 0, 3, 5, 7, 10, and 15 days, chicken sausage will be cooked by pan-broiling for 0.5, 1.0, 1.5, 2.0, 3.0, 5.0 or 10.0 min per side a Presto® electronic skillet set at 176.7oC or 232oC, or roasting for 1, 2, 4, 6, 10, 15, 20 or 30 min in a convention kitchen oven with setting at 232oC. The temperatures of the meat and cooking appliance will be monitored and recorded using Type K thermocouples. Populations of Salmonella spp. and total microorganism will be tested before and after cooking. To evaluate potential development of thermal resistance, chicken meat will be prepared with variable fat contents (5 or 10%). Furthermore, marinated chicken with various types of commercial antimicrobials (e.g., lactic acid, citric acid, acidified sodium chlorite, peracetic acid, cetylpyridinium chloride, sodium metasilicate) and different ratios of meat to marinades (e.g., 2:1, 1:1, 1:2) will be evaluated for development of thermal inactivation activity. Chicken samples will be placed in Whirl-Pac filter bag with maximum recovery dilutes (MRD; 0.85% NaCl and 0.1% peptone) at a 1:1 ratio of sample weight (g) verse volume (ml) and homogenized for 2 min (Masticator, IUL Instruments). The stomached samples will be serially diluted in 0.1% buffered peptone water (Difco, Becton Dickison), and surfaced plated for Salmonella populations on XLT-4 agar, Colonies of Salmonella and total microorganism will be manually counted after incubating plates at 35?C for 24 h and 25?C for 72 h, respectively. For pathogen survivals below detection limit, an enrichment procedure using tryptic soy broth for 24-72 h aerobic incubation followed by streaking plating will be conducted to detect the presence/absence of pathogens after thermal treatments. Experimental design in this project will include factorial, completely randomized, nested or block designs with 3-5 repeats, and in each repeat, 3-4 samples will be analyzed per treatment using the ProcMixed Procedure of SAS.</p>