New Research on Natural Preservatives: Potassium Cinnamate Shows Promise as a Replacement for Chemical Preservatives – Antimicrobial Mechanism and Safety Confirmed by Authoritative Study

Latest Findings Published in LWT-Food Science and Technology, 2025

Food spoilage and contamination by foodborne pathogens remain major challenges for the global food industry. Currently, the industry widely uses chemical preservatives such as sodium benzoate and potassium sorbate to extend shelf life. However, excessive use of these additives may pose potential risks to human health and the environment, such as metabolic interference and even chronic diseases from long-term overconsumption. Therefore, the search for safe and effective natural preservatives has become a research hotspot.

A recent study published in the international journal LWT-Food Science and Technology (Issue 215, 2025) revealed that potassium cinnamate, a natural compound, exhibits excellent antimicrobial activity and biological safety, making it a promising alternative to chemical preservatives in the food industry. The research was jointly conducted by the Key Laboratory of Fermentation Engineering (Ministry of Education) at Hubei University of Technology, the State Key Laboratory of Bioreactor Engineering at East China University of Science and Technology, and other institutions. The team systematically demonstrated the inhibitory effects and mechanisms of potassium cinnamate against common foodborne pathogens.

1. Significant Antimicrobial Activity, Superior to Multiple Chemical Preservatives

The study found that the antimicrobial efficacy of potassium cinnamate is comparable to sodium dehydroacetate and superior to sodium benzoate and potassium sorbate. Specific data are as follows:

• Minimum Inhibitory Concentrations (MIC): Staphylococcus aureus – 2 mg/mL, Escherichia coli – 4 mg/mL, Shigella boydii – 1 mg/mL, Bacillus cereus – 1 mg/mL.
• Minimum Bactericidal Concentrations (MBC): S. aureus, E. coli, S. boydii – 16 mg/mL; B. cereus – 8 mg/mL.

• Particularly for B. cereus, which is heat-resistant and spore-forming, potassium cinnamate achieved an MIC of only 1 mg/mL, compared to 2 mg/mL for sodium benzoate and 4 mg/mL for potassium sorbate. This clearly demonstrates its potential to replace sodium benzoate, potassium sorbate, and sodium dehydroacetate as a natural food preservative.

2. Clear Antimicrobial Mechanism – Multi-Target Inhibition of Pathogens

The study also revealed the underlying antimicrobial mechanism of potassium cinnamate:

• Scanning electron microscopy showed that untreated bacterial cells had smooth, intact surfaces, while cells treated with increasing concentrations of potassium cinnamate exhibited surface damage, wrinkling, inward collapse, and eventual rupture.This indicates that potassium cinnamate induces morphological changes in foodborne pathogens, causing irreversible structural damage and thus exerting antimicrobial effects.
• These observations, together with findings such as “disruption of cell membrane integrity leading to leakage of intracellular contents,” confirm that potassium cinnamate acts through multiple antimicrobial pathways, including inhibition of biofilm formation, increase of intracellular reactive oxygen species, DNA damage, and suppression of energy synthesis.

3. High Biological Safety – Harmless Metabolic Pathway

Safety assessments, including hemolysis and cytotoxicity tests, confirmed the high safety profile of potassium cinnamate:

• In hemolysis tests, even at 8 mg/mL, potassium cinnamate showed a hemolysis rate of only 3.31 ± 0.17% for rabbit red blood cells—far below the safety risk threshold.
• In cytotoxicity tests, 8 mg/mL potassium cinnamate maintained a cell viability of 86.94 ± 0.21% for K562 human leukemic cells, indicating extremely low cytotoxicity within the effective antimicrobial range (1–4 mg/mL).

In terms of metabolism, potassium cinnamate is converted in the human body into phenylalanine (an essential amino acid), with most excreted through normal metabolic processes and a small portion converted into tyrosine. The entire metabolic pathway produces no toxic or harmful effects. Notably, its active preservative component, cinnamic acid, was recognized as GRAS (Generally Recognized As Safe) by the Flavor and Extract Manufacturers Association (FEMA) as early as 1965.

In summary, with its strong antimicrobial activity and reliable biological safety, potassium cinnamate holds great promise as a natural alternative to chemical preservatives in the food industry, offering a new solution to the challenges of food spoilage and pathogen contamination.