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The objective of the current study was to evaluate the color changes and lipid oxidation of ground chicken patties packaged in polyvinyl chloride (PVC) film, high-oxygen (HiOx)–modified atmospheric packaging (MAP; 80% oxygen + 20% carbon dioxide [CO2]), and carbon monoxide (CO)-MAP (0.4% CO + 19.6% CO2 + 80% nitrogen) and stored at 2°C. Surface color was measured using a HunterLab MiniScan spectrophotometer on days 0, 1, 2, and 4. Lipid oxidation, pH, and aerobic plate count were determined on days 0 and 4 of storage. Fatty acid profiles were determined on day 0 to characterize saturated and unsaturated fatty acids. Patties packaged in PVC had greater (P < 0.05) pH than HiOx-MAP and CO-MAP. Gas chromatography analysis indicated that ground chicken has 72.8% unsaturated fatty acids and 27.2% saturated fatty acids (based on total lipids and fatty acid methyl ester). The formation of carboxymyoglobin on ground chicken patty surface was confirmed by peaks at 420 and 570 nm, whereas oxymyoglobin had peaks at 410 and 580 nm. Instrumental color analysis indicated both HiOx-MAP and CO-MAP had greater (P < 0.05) redness (a* values) than PVC on day 4 of storage. Patties packaged in HiOx-MAP had greater (P < 0.05) chroma values than CO-MAP and PVC on day 4 of storage. Visual panelists noted less (P < 0.05) surface discoloration in CO-MAP than PVC and HiOx-MAP on day 4 of storage. Lipid oxidation was greater (P < 0.05) in PVC and HiOx-MAP than CO-MAP. CO inclusion at 0.4% level effectively inhibited lipid oxidation and stabilized surface redness during refrigerated storage of ground chicken.

Cooking temperature of poultry meat is typically inadequate to inactivate the heat resistant spores of Clostridium botulinum. The purpose of this study is to develop a predictive model for C. botulinum during cooling of cooked ground chicken. Cooked chicken was inoculated with a cocktail of five strains of proteolytic C. botulinum type A and five strains of proteolytic C. botulinum type B to yield a final spore concentration of approximately 2 log CFU/g. The growth of C. botulinum was determined at constant temperatures from 10 to 46 °C. Dynamic temperature experiments were performed with continued cooling from 54.4 to 4.4 °C or 7.2 °C in mono- or bi-phasic cooling profiles, respectively. The Baranyi primary model was used to fit growth data and the modified Ratkowsky secondary model was used to fit growth rates with respect to temperature. The primary models fitted the growth data well (R2 values ranging from 0.811 to 0.988). The R2 and root mean square error (RMSE) of the modified Ratkowsky secondary model were 0.95 and 0.06, respectively. Out of 11 prediction error values calculated in this study, ten were within the limit of acceptable prediction zone (−1.0 to 0.5), indicating a good fit of the model. The predictive model will assist institutional food service operations in determining the safety of cooked ground chicken subjected to different cooling periods.

This study was conducted to determine safe cooking times for mechanically tenderized beef steaks prepared from the round, loin, rib, and chuck. The subprimals were needle tenderized and fabricated to prepare a total of 180 steak cuts with varying weights and thicknesses. Steaks were then vacuum packaged and stored at refrigerated temperature until cooked. The dimensions and weight of the steaks were measured pre- and post-cooking. Samples were cooked on a flat-top grill until they reached an internal temperature of 71.1 °C. During cooking, a thermocouple recording device recorded the steak center temperature every 10 s. It was observed that the time required for the steak to reach 71.1 °C significantly influenced by the thickness and type of subprimals of steak. The average cooking yield of steak was 75.66%, while the safe cooking time ranged from 2.22 to 36.66 min. This study could provide valuable information about the effects of weight, thickness and muscle type on the cooking time required for mechanically tenderized beef steaks to reach a minimum safe cooking temperature, without a resting period.

This article provides a comprehensive literature review of the growing significance that foodborne pathogens have on the produce supply and the steps that are taken to reduce them. The numbers of illnesses that are caused by contaminated produce are rising steadily. Three of the most common pathogens that have been seen to cause significant illness in humans through produce are Escherichia coli, Salmonella spp. and Listeria monocytogenes. The antimicrobial interventions, practices and antimicrobials that are currently the most commonly used by the food industry are examined. The literature shows that these antimicrobials currently in use have significant drawbacks when it comes to their role in the produce industry. Sensitivities to temperature and organic load and the production of harmful by products are some of these drawbacks. There is a need for a new antimicrobial that can be used in the produce processing industry. One that maintains its efficacy through the temperature, pH, and organic load changes that are experienced during produce processing. Sodium acid sulfate is a potential contender for this role. It has not previously been used or extensively studied as an antimicrobial, but is already deemed generally recognized as safe (GRAS) product by the Food and Drug Administration (FDA). The use of an antimicrobial that can withstand the varying conditions that the produce industry constantly has is imperative to reducing the number of foodborne illness caused every year by contaminated produce.

Microbial safety issues related to mechanically tenderized beef have become prevalent, resulting in new labeling regulations for mechanically tenderized raw or partially cooked beef products. These products must bear labels to include validated cooking instructions, with specifications for minimum internal temperatures, to ensure that they are fully cooked. However, validation of cooking instructions for individual steak cuts of different sizes and weights is costly and time consuming. The objective of this study was to utilize predictive modeling techniques to determine safe cooking times for various mechanically tenderized steaks, cooked to an internal temperature of 70 to 71°C. A total of 162 steaks of various types (top round, knuckle, strip loin, top sirloin, sirloin cap, tri-tip, ribeye, flap, and flank), thicknesses (1.27, 2.54, and 3.81 cm), and weights (113 to 567 g) were used. Prior to cooking, samples were needle-tenderized, cut, vacuum-packaged, and refrigerated. Steak dimensions (width, thickness, and length) were measured prior to each cooking experiment. Samples were cooked on a flat-top-grill until they reached an internal temperature of 70 to 71°C, and the time taken to reach that temperature was defined as the Experimental Safe Cooking Time (ESCT). A thermocouple, attached to a data logger, recorded the steak-center temperature every 10 s. The time-temperature profiles obtained were used to determine the rate of temperature increase (RTI). Data generated through the experiments was used for model development and determination of predicted safe cooking time (PSCT) for steaks. The thickness, weight, and RTI of the steaks were identified as factors that had a 60% or higher correlation with the ESCT. Prediction accuracy of the regression model was 79%, with no significant differences (P < 0.01) between the ESCT and PSCT. This approach could help the meat industry formulate safe cooking times of various steak cuts, without repeating costly validation studies.

The objective of this research was to determine the effects of nitrite-embedded/FreshCase packaging on lean color of dark-cutting beef. Eight dark-cutting (pH > 6.0) and eight USDA Low Choice (normal-pH; mean pH = 5.6) beef strip loins (longissimus lumborum) were selected 3 day after harvest. Each dark-cutting loin was sliced into five 2.5-cm thick steaks and randomly assigned to 1) dark-cutting steak packaged in polyvinyl chloride film (PVC) overwrap, 2) dark-cutting steak packaged in nitrite-embedded film, 3) dark-cutting steaks dipped in 0.2% rosemary solution and packaged in nitrite-embedded film, and 4) dark-cutting steak dipped in deionized water and packaged in nitrite-embedded film. The fifth dark-cutting steak was used to determine pH and proximate composition. Normal-pH choice loins were used as a control and each loin was randomly assigned to either PVC overwrap for retail display or to determine pH and proximate composition. Packages were placed in coffin-style retail display cases under continuous fluorescent lighting for 3 days. A HunterLab MiniScan XE Plus spectrophotometer was utilized to characterize steak color every 24 h. There was a significant treatment × storage time interaction (P < 0.05) for a* values and nitric oxide myoglobin formation. On days 1, 2, and 3 of the display, nitrite-embedded treatment improved (P < 0.05) redness compared to other dark-cutting steaks in PVC. A 45% increase in redness (P < 0.05) was observed for nitrite-embedded rosemary treatment over dark-cutting steak in PVC on day 3 of display. Nitric oxide myoglobin formation on day 0 was less for all dark-cutting steaks in nitrite-embedded packaging. Metmyoglobin content was greater (P < 0.05) on day 0 for dark-cutting steaks packaged in nitrite-embedded treatments than dark-cutting steaks in PVC. However, metmyoglobin level in dark-cutting steaks packaged in nitrite-embedded treatments decreased (P < 0.05) on day 1 compared with day 0. Dark-cutting steaks packaged in PVC had greater (P < 0.05) L* values on day 0 than other dark-cutting steaks in nitrite-embedded packaging. Conversely, on days 1, 2, and 3, there were no differences (P > 0.05) in L* values between dark-cutting treatments. Dark-cutting steaks in nitrite-embedded packaging had lower total plate count (P < 0.05) than dark-cutting steak packaged in PVC. The current research indicated that nitrite-embedded packaging has the potential to improve surface color of dark-cutting beef.

This study aims to identify the antimicrobial mode of action of sodium acid sulfate (SAS) and potassium acid sulfate (KAS) against three major foodborne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT 104, and Listeria monocytogenes. The overnight grown cultures of the target pathogens were subjected to SAS and KAS treatments to identify the minimum inhibition concentrations of each antimicrobial. The impact of SAS and KAS treatments on the target pathogens at bio-molecular levels was also studied. To help determine if the mode of action is pH-driven, SAS and KAS's antimicrobial efficacies were also compared against hydrochloric acid (HCL). The MIC values of SAS and KAS for all three pathogens were 7.5 mg/mL while for HCL, the MICs were greater than 30 mg/mL. Similarly, SAS and KAS treatments resulted in more damage to all target pathogens and increased leakage of nucleic acid, protein, and ions than HCL treatments. Transmission electron microscope images also revealed that 7.5 mg/mL SAS and KAS treatments resulted in significantly more visible cell damage in S. Typhimurium and E. coli O157:H7 than HCL treatments. The study's findings indicate that the SAS and KAS could be the function of pH, oxidation of cell components, and osmolarity.

Escherichia coli O157:H7 biofilms pose challenges to the food industry by facilitating pathogen persistence. Sodium acid sulfate (SAS), a food-acid with antimicrobial properties, is poorly understood for its biofilm-disrupting capabilities. Efficacy of SAS (0.1, 1, and 3%), to disrupt E. coli O157:H7 biofilms in-vitro and on food-contact surfaces, was compared with water, chlorine (200 ppm) and peracetic-acid (PAA; 200 ppm). Biofilms were formed in 96-well-plates or on stainless-steel (SS) and high-density-polyethylene (HDPE) at 0, 10 and 480 min. In-vitro biofilm disruption was determined by measuring absorbance (A595) of crystal violet bound to the biofilm. Biofilm disruption on SS and HDPE was visualized using scanning electron microscopy (SEM) and pathogen populations enumerated. Overall, SAS-treatments significantly (P

Fresh fish and seafood are highly perishable, and microbiological spoilage is one of the important factors that limit their shelf life and safety. Fresh seafood can be contaminated at any point from rearing or harvesting to processing to transport or due to cross-contamination by consumer mishandling at home. With the increase in the demand for fish and seafood, aquaculture production is increasing, which could lead to new risks that will need to be addressed in the future to control foodborne pathogens.