Most outbreaks of foodborne illness in the United States occur as a result of improper food-handling and preparation practices in homes or food establishments. Some food-safety recommendations that are difficult to incorporate into handling and cooking procedures have contributed to a gap between food-safety knowledge and the actual behavior. The first part (Chapter 3, 4) of this study sought to ensure microbial safety by establishing alternative processing of meat products that can be easily practiced by food-operators and consumers. In Chapter 3, a novel method was developed to thaw frozen chicken-breast by submersion in hot water at 60 °C, an appropriate temperature setting for foodservice hot-holding equipment. This method is rapid (compared to either refrigerator or cold-water thawing that also uses a significant amount of water), safe, and the final cooked-product sensory-quality was not different from refrigerator-thawed and cooked product (microwave thawing results in localized overheating). Chapter 4 developed marinade-cooking (91 °C) and holding (60 °C) procedures for hamburger-patties. Frozen patties were partially grilled and finished cooking in marinade. The moderate temperature of marinade cooking overcomes the chances of thick-patties being surface-overcooked while innermost portions remain undercooked as seen in high-temperature cooking methods (grilling and pan-frying). Consumers liked the marinade-finished cooked and held patties (up to 4 h) equally or more (holding-time dependent) compared to patties grilled and held in a hot-steam cabinet. Reducing salt in perishable foods including cheese is microbial-safety concern especially in their distribution and storage. The second part (Chapter 5, 6) of this study sought to evaluate microbial safety of low-salt hard-type cheese. Aged Cheddar cheeses were inoculated with either Listeria monocytogenes (3.5 log CFU/g) or Salmonella spp. (4.0 log CFU/g) and their survival or growth was monitored at 4, 10, and 21°C for up to 90, 90, and 30 d, respectively. Low-salt (0.7% NaCl) Cheddar formulated at pH 5.1 or 5.7 exhibited no-growth or gradual reduction in L. monocytogenes and Salmonella counts. The results suggest that low-salt Cheddar is as safe as its full-salt counterparts (1.8% NaCl) and that salt may only be a minor food-safety hurdle regarding the post-aging contamination and growth of L. monocytogenes and Salmonella.

The poultry industry is seeking an advanced chilling system that can improve chilling efficiency, microbial safety, and water consumption without compromising meat quality. The objective of this study was to evaluate the effects of sub-zero saline chilling methods on chilling efficiency, breast fillet tenderness and microbial reduction of broiler carcasses. Following evisceration and rinsing, broiler carcasses were randomly assigned to one of three chilling solutions: 1) 0% salt or ice water control (0% NaCl/0.5oC), 2) 3% salt (3% NaCl/-1.8oC), and 3) 4% salt (4% NaCl/-2.41oC) solutions. Broiler carcasses in sub-zero saline solutions reached the target internal temperature of < 4.4 oC in a faster rate than the 0% salt control, reducing the chilling time by 11% and 39 % for 3% NaCl/-1.8oC and 4% NaCl/-2.41oC solutions, respectively. There was no significant difference in breast fillet pH, regardless of chilling treatment (P < 0.05). However, the breast fillets from sub-zero saline solutions showed higher R-value and longer sarcomere length than those of control fillets (P < 0.05). Breast fillets excised from carcasses in 4% NaCl/2.41oC were significantly tenderized more than the control fillets, with an intermediate tenderness observed for the fillets from 3% NaCl/-1.8oC (P< 0.05). Before chilling, broiler carcasses contained mesophilic aerobic bacteria (MAB), Escherichia coli(E. coli), and total coliforms for 3.81, 0.78, and 1.86 log colony forming unit (CFU)/g, respectively. After chilling, the populations of E. coliand total coliforms were significantly reduced on the carcasses in 3% NaCl/-1.8oC and 4% NaCl/-2.41oCcompared to the control fillets (P< 0.05). There was no significant difference for MAB populations, regardless of treatment. Based on these results, chilling of broiler carcasses in 4% NaCl/-2.4 °C solution seems to be the best choice to improve chilling efficiency, meat tenderness, and microbial reduction compared to the control (0% NaCl/0.5ºC) and 3% NaCl/-1.8oCsolutions.