Potassium Cinnamate

As a natural food preservative, potassium cinnamate possesses the following characteristics: 1.1 It exhibits strong broad-spectrum antibacterial activity, particularly effective against molds, bacteria, and yeasts that cause food spoilage. The effective concentration for inhibiting molds is 0.05-0.1%, with a typical usage range of 0.01-0.02%. The effective concentration for inhibiting bacteria ranges from 0.01-0.1%. The main targets of its inhibition also include Pseudomonas, Micrococcus, Bacillus, various genera of Enterobacteriaceae, Vibrio, Halobacterium, Aerobacter, Lactobacillus, Lactic acid bacteria, aflatoxin, Escherichia coli, Proteus vulgaris, Lactobacillus casei, Clostridium butyricum, Lactobacillus gerovicius, Aerobacillus, Gram-negative and Gram-positive bacilli, Clostridium botulinum, etc. Additionally, potassium cinnamate is not limited by pH, exhibiting a considerable antibacterial effect within a pH range of 2-7, and this effect remains consistent despite fluctuations in pH. It can be widely applied in various types of food.

1.2 Safety and practicality: The oral LD50 of potassium cinnamate in rats is 5.58-6.78g/kg, indicating that it is a non-toxic product. After absorption by the human body, potassium cinnamate is converted into phenylalanine, which is metabolized and excreted from the body. A small amount of phenylalanine can be catalyzed by phenylalanine hydroxylase to generate tyrosine, which poses no toxic side effects to the human body. Its effective preservative component, cinnamic acid, was recognized as GRAS (Generally Recognized as Safe) by FEMA (Flavor Extract Manufacturers Association) in 1965.

1.3 The effective preservative component of functional potassium cinnamate is also a natural differentiation inducer that has a differentiating effect on various cells, namely, it possesses health-care functions such as anti-fatigue, promoting metabolism, anti-inflammatory, anti-cancer, vasodilatation, maintaining excitement, and lowering blood pressure.

2. Preservative Properties of Potassium Cinnamate Potassium cinnamate is the potassium salt of cinnamic acid, a natural cinnamon extract. Due to its good solubility, it is widely used in food. Its preservative mechanism is that potassium cinnamate converts to cinnamic acid under acidic conditions. Cinnamic acid is a weak acid with a pKa of 4.37-4.44, and its antimicrobial effect relies on its predominantly unionized acid molecule form. When dissolved in water, the weak acid does not fully ionize into ions, but forms an equilibrium between charged, ionic forms and uncharged, non-ionized forms. The ratio of the two forms depends on the pH of the solution. The more acidic the solution, the more unionized forms there are. Since the 1950s, it has been understood that the antimicrobial action of cinnamic acid is achieved by inhibiting the utilization of phenylalanine and tyrosine by microorganisms. In its unionized form, cinnamic acid, as a weak acid preservative, is believed to be soluble in microbial membranes, enter cells, ionize in higher pH environments, and thus reduce internal pH, effectively affecting the activity of many important enzymes and ultimately killing contaminating cells.

3 Health and Pharmacological Studies of Potassium Cinnamate 3.1 Anti-tumor Potassium cinnamate exhibits anti-tumor effects and has anti-mutagenic activity in vitro, capable of inhibiting various tumors induced by carcinogens in rodents. Studies have found that the active ingredient of potassium cinnamate, cinnamic acid, can inhibit the proliferation of cell lines such as human glioblastoma, melanoma, and hormone-insensitive prostate cancer. It reverses the malignant phenotype and inhibits the invasion of highly metastatic human lung cancer cells. It can also induce the differentiation of human lung adenocarcinoma cells, human liver cancer cells, and human promyelocytic leukemia cells, making it a natural differentiation inducer with potential application in various cell types. Cinnamic acid is an effective inhibitor of A-5491 human lung adenocarcinoma cells and has great potential application value in anti-cancer therapy. It can increase blood leukocyte count, resist radiation, and also has anti-tumor, anti-lung tumor, and anti-tuberculosis effects.

3.2 Lowering Blood Glucose and Blood Lipids Kang-Beom Kwon et al. administered potassium cinnamate to streptozotocin (STZ)-induced diabetic mice at high, medium, and low doses for 7 consecutive days. The blood glucose levels of normal control group mice showed no significant effect, while the treated group mice exhibited a significant hypoglycemic effect, with blood glucose levels decreasing in a dose-dependent manner across the high, medium, and low dose groups. Plasma insulin levels also significantly increased in a dose-dependent manner.

Diabetes is a common endocrine and metabolic disease, often accompanied by lipid metabolism disorders and hyperlipidemia. Long-term hyperglycemia and hyperlipidemia are highly prone to induce diabetic cardiovascular and cerebrovascular diseases. In the treatment of diabetes, lowering blood lipids is almost as important as lowering blood glucose. Multiple experimental results have shown that potassium cinnamate can not only lower blood glucose but also reduce blood lipids, suggesting that potassium cinnamate has a certain effect on the prevention and treatment of diabetes and its complications.

3.3 Antibacterial and anti-fatigue potassium cinnamate can be directly added or compounded to manufacture local anesthetics, bactericides, and hemostatic agents, and it also possesses anti-fatigue properties. It has good antibacterial and trichomonas-killing effects, and has certain therapeutic effects on wound healing, making it suitable for use in external medications such as band-aids. It has sedative effects and can supply sufficient blood to the heart, achieving the effect of calming the body and nourishing the heart. It also has anti-platelet aggregation properties, promotes metabolism, resists enteritis, and has anti-inflammatory effects. It can be directly used as a stimulant and has excellent efficacy.

3.4 Potassium cinnamate is a spice in itself, possessing excellent aroma retention properties. It is commonly used as a fragrance ingredient to enhance the fragrance and volatility of the main fragrance.

Various esters of cinnamic acid (such as methyl, ethyl, propyl, butyl, etc.) can be used as flavor fixatives for beverages, cold drinks, candies, wines, and other foods. n-Propyl cinnamate, also known as β-phenylpropanoic acid n-propyl ester, has a unique peach-apricot and wine-like aroma and is widely used in flavorings for food, tobacco, cosmetics, and soaps. It is a flavor to be developed. Meanwhile, potassium cinnamate can also be used as a flavoring agent for apple essence, cherry essence, fruit essence, and floral essence; it can be used as an aromatic mixture in soaps, shampoos, laundry detergents, and daily cosmetics. In the application of cosmetics, it has the effect of inhibiting the formation of melanin tyrosinase, has a certain UV blocking effect, can lighten or even eliminate brown spots, and is an essential ingredient in high-grade sunscreen.