Compendium of the most significant studies with reference to properties, intake, effects.

Rusul G, Marth EH. Growth and Aflatoxin Production by Aspergillus parasiticus NRRL 2999 in the Presence of Potassium Benzoate or Potassium Sorbate and at Different Initial pH Values. J Food Prot. 1987 Oct;50(10):820-825. doi: 10.4315/0362-028X-50.10.820.

Abstract. Experiments were done to determine how different concentrations of potassium benzoate or potassium sorbate in a glucose-yeast extract-salts medium with an initial pH value of 3.5, 4.5 or 5.5 affected growth and aflatoxin production by Aspergillus parasiticus NRRL 2999. The pH of the medium, weight of mycelium and amount of aflatoxin produced were determined after 3 and 7 d of incubation. Aflatoxin was determined using reversed-phase high-performance liquid chromatography. Maximum concentrations of potassium sorbate and potassium benzoate that permitted growth were 0.2% and 0.4%, respectively, in a medium with an initial pH of 5.5. When the initial pH was 4.5, the maximum concentrations of potassium sorbate and potassium benzoate that permitted growth were 0.05% and 0.10%, respectively, but there was an extended lag phase. Increasing concentrations of potassium benzoate or potassium sorbate decreased amounts of aflatoxin B1 and G1 produced after 3 d in a medium with initial pH values of 5.5 or 4.5. Cultures growing in the medium containing 0.1, 0.15 or 0.20% potassium benzoate or potassium sorbate and with an initial pH of 5.5 were somewhat inhibited at 3 d of incubation, which was characterized by a slow decrease in pH, low mycelium dry weight and small amounts of accumulated aflatoxins. After 7 d these cultures overcame the initial inhibition and produced substantial amounts of aflatoxins and mycelium. This was also true for cultures growing in a medium with an initial pH of 4.5 and containing potassium benzoate or potassium sorbate. By decreasing the initial pH of the medium from 5.5 to 4.5, amounts of potassium benzoate or potassium sorbate required to achieve inhibition decreased by a factor of 10.

Afshar M, Moallem SA, Khayatzadeh J, Shahsavan M. Teratogenic effects of long term consumption of potassium benzoate on eye development in BALB/c fetal mice. Iran J Basic Med Sci. 2013 Apr;16(4):593-8.

Abstract. Objective(s): Potassium benzoate (PB) is used as a substitute preservative for sodium benzoate primarily in dietetic foods where the sodium content is minimized. There are few reports about the teratogenic effects of PB. The purpose of this study is to investigate the teratogenic effects of PB on eye development in balb/c mice fetuses....Results: Fetuses with eye malformations observed in both experimental groups of I and II. The incidence of these malformations was significantly increased in fetuses of experimental group II as compared with the control group (P<0.05). Histopathological evaluations of the malformed eyes showed deformed lens, retinal folds with undeveloped layers associated with hemorrhage. Conclusion: Our results suggest that PB can induce teratogenic effects on the eye development of mice fetuses. Therefore, more concise studies are needed regarding its specific and general effects conducted.

Butterhof, C., Martin, T., Milius, W., & Breu, J. (2013). Microphase separation with small amphiphilic molecules: crystal structure of preservatives sodium benzoate (E 211) and potassium benzoate (E 212). Zeitschrift für anorganische und allgemeine Chemie, 639(15), 2816-2821.

Abstract. In the pharmaceutical industry many new active pharmaceutical ingredients (APIs) are marketed as carboxylic salts because of enhanced solubility and dissolution rates. These salts are, however, often hard to crystallize and/or exhibit a low degree of crystallinity. The reason may be found in the largely differing sizes of small inorganic cations and large organic anions in conjunction with the 1:1 stoichiometry, which makes it difficult to satisfy the coordination needs of the cations. Even rather small amphiphilic molecules like the widely used preservatives sodium benzoate (NaBz) and potassium benzoate (KBz) suffer of the same obstacle to crystallization. Both of these industrial products are marketed in semi-crystalline forms and no crystal structures were known up to now despite their industrial relevance. By applying long term annealing at 420 °C for 5 months we obtained tiny needle-like crystals of NaBz, which were nevertheless suitable for single crystal structure determination. Interestingly, the number of symmetry independent units in the crystal structure is exceptionally high (Z′ = 5), reflecting the difficulties in satisfying the coordination. Moreover, the small amphiphilic molecule undergoes a microphase separation into tubes with a hydrophilic core and a hydrophobic corona made up by the phenyl moieties. The tubes are arranged into a distorted hexagonal dense packing. Such microphases are well established with surfactants and block-copolymers, and it seems that even small amphiphilic molecules follow the same modes of crystallization. Interestingly, simply by changing the cation to KBz a competing microphase structure is realized. KBz crystallizes in a lamellar arrangement.

SA, M., & GH, N. (2011). Effect of potassium benzoate on BALB/c mice placenta: a histopathological study.

Abstract. The food additives, like sodium and potassium benzoate are used in many food products and drugs to prevent the growth of yeast and molds. There is no report about the histopathological effect of potassium benzoate. Placenta, has a critical role in embryonic development therefore this study was set up to evaluate the effects of potassium benzoate on placenta of BALB/c mice. 45 BALB/c female mice were allocated into two experimental [1, 2] and one control groups. Experimental groups received daily intraperitoneal injection of 280 and 560 mg/kg/body weight of potassium benzoate and control group received normal saline. All injections were done during 10 days before mating and 5th to 16th of gestational days [GD]. In GD 18 all placenta were removed via cesarean section. Macroscopic studies for morphological abnormalities were done and after measuring of placental weight and diameter, for microscopic studies the specimens were fixed and tissue passage were done. Tissue sections were stained with hematoxylin-eosin and histopathological changes were studied. Weight, diameter and percentage of agenesis of placenta in all groups were gathered. Data analyzed with using SPSS-11.5, ANOVA and Tukey tests. The mean weight and diameter of the placenta in both experimental groups 1 and 2 were significantly decreased compared to control group. Also atrophy of placenta in the experimental groups was increased significantly compared to the control group [P<0.05]. Comparison of weight and diameter between groups 1 and 2 was not significant. Percentage of placenta agenesis in the experimental groups was increased significantly compared to the control group [P<0.05]. Massive hemorrhage in labyrinth zone, fetal and maternal zones were seen in both experimental groups. This study showed that exposure of potassium benzoate during mice pregnancy cause morphological and histopathological changes of placenta, including decrease of weight and diameter, agenesis, hemorrhage and tissue disorders.

Szammer, J., & Noszkó, L. (1971). Investigation of the thermal decomposition of potassium benzoate in the presence of cadmium and zinc compounds. Journal of Thermal Analysis and Calorimetry, 3(2), 149-152.

Abstract. It was established by thermogravimetric measurements that the thermal decomposition of potassium benzoate in the presence of inorganic cadmium or zinc salts results in the formation of the easily decomposing cadmium or zinc benzoate. These carboxylates are presumably the catalysts of the transcarboxylation of potassium benzoate to terephthalate.