Effects of sodium chloride, sodium lactate, and sodium diacetate on the growth probabilities of Salmonella and Staphylococcus aureus

Authors: Hwang, Cheng An; Huang, Lihan; Sheen, Shiowshuh - Allen

Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Salmonella and Staphylococcus aureus have been linked to foodborne illnesses caused by processed meat products. This study examined the growth probabilities of the pathogens as affected by salt (3-8%, aw 0.98-0.93), sodium lactate (0-2.4%), and sodium diacetate (0-0.25%) in a solid medium to identify the use of these three food additives to improve microbial safety of meat products. The minimum concentrations of salt, lactate, and diacetate that inhibited the growth of Salmonella and S. aureus were obtained and validated in a cooked meat products. Mathematical models were developed to describe the effects of the additives on the growth probabilities of Salmonella and S. aureus. Findings from this study could be used for formulating refrigerated and shelf-stable meat products to reduce Salmonella and S. aureus risk.

Technical Abstract: Salmonella and Staphylococcus aureus have been linked to foodborne illnesses caused by the consumption of processed meat products. This study examined the growth probabilities of the pathogens as affected by sodium chloride (salt), sodium lactate, and sodium diacetate in a solid medium to identify the use of these three food additives to improve microbial safety of processed meat. Sterilized tryptic soy agar (200 µl) formulated with a combination of salt (3-8%, aw 0.98-0.93), lactate (0-2.4%), and diacetate (0-0.25%) and inoculated with Salmonella or S. aureus was dispersed into 96-well microplates and incubated at 37 deg. C for 3 days. After incubation, if a well had any Salmonella or S. aureus colonies was denoted as growth, otherwise no-growth. The effects of the additives on the growth event were analyzed by logistic regression to identify the growth and no-growth boundaries and to develop formulations that may prevent the growth of Salmonella or S. aureus. For Salmonella, the observed minimum no-growth concentrations were 3% salt with 0.8% lactate+0.2% diacetate or 1.6% lactate+0.1% diacetate, 4% salt with 2.4% lactate, 5% salt with 0.25% diacetate, 6% salt with 0.8% lactate+0.15% diacetate, 7% salt with 0.8% lactate or 0.15% diacetate, and 8% salt alone. For S. aureus, the concentrations were 3% salt with 2.4% lactate+0.2 diacetate, 5% salt with 1.6% lactate+0.2% diacetate, 7% salt with 0.8% lactate+0.25% diacetate, and 8% salt with 0.8% lactate+0.20% diacetate or 1.6% lactate+0.15% diacetate. These no-growth formulations were validated in meat samples and were shown to inhibit the growth of both pathogens. Mathematical models were developed to describe the effects of the additives on the growth probabilities of Salmonella and S. aureus. Findings from this study may be used for formulating refrigerated and shelf-stable meat products to reduce Salmonella and S. aureus risk.