Sodium Benzoate & Potassium Sorbate
Introduction
Yen Thi Hai Hoang (2016) writes, related to processed meats and its consumption in ho ChiMinh City in Vietnam that a “problem associated with these products is its short shelf life due to a high level of nutrients, microbiological enzymatic or chemical changes which occur duringthe storage period.” This is of course true across the world. They continue that “these food products consist of a variety of microbes such as bacteria, yeasts, and molds which have been reported as the original agents of foodborne diseases or food spoilage. As a consequence, the use of preservatives has become more outstanding in the food industry, especially in processed and convenience foodstuffs.” In Vietnam, the “most commonly used preservatives are sodium benzoate and potassium sorbate.”
“The consequence of food preservatives for consumers has always been a health safety concern. Although sodium benzoate and potassium sorbate are generally recognized as safe (GRAS) but the increase of allergic reactions to benzoate in humans, such as urticaria, rash, migraine, hyperkalemia, non-immunological contact urticaria, metabolic acidosis, convulsions, hyperpnea, weak clastogenic activity and asthma has been reported in some studies. Potassium sorbate has a relatively low toxicity in humans. Moreover, if the concentration of sodium benzoate exceeds the regulated amounts, it may cause hyperactive behaviour in children when combined with some artificial colors. In human, some evidence of idiosyncratic intolerance to sorbate salts have been addressed. In addition, potassium sorbate combined with ascorbic acid (vitamin C) is a chance for mutagenicity developed and DNA-damaging activity, while sodium benzoate causes carcinogenesis due to the cause of benzene, a carcinogenic agent. It may cause a danger to public health if the concentrations of the two preservatives exceed the regulated amounts. Especially, children are the most sensitive group to these preservatives.” In Vietnam, “the maximum level (ML) of sodium benzoate and potassium sorbate in processed meat products imposed by the Ministry of Public Health is 1000 ppm.” My notes on the levels prescribed by Codex as well of other relevant characteristics of these two preservatives are given below. (Yen Thi Hai Hoang, 2016)
Recommended dosage
It is recommended to use both potassium sorbate and sodium benzoate in combination with vitamin C.
Pot Sorbate: 0.1% of FP
Sodium Benzoate: 0.1% of FP
Vitamin C: 0.17%
Potassium Sorbate, Sodium Benzoate and Nitrite Combination
The combination of Sodium Benzoate, Potassium Sorbate and Sodium Nitrite is a known preservative of silage under aerobic conditions. Knicky (2015 reports that “overall, adding 5mL/kg of fresh crop of the additive based on sodium nitrite, sodium benzoate, and potassium sorbate reduced undesirable microorganisms in silages and thereby provided suitable ensiling conditions and prolonged aerobic stability, even under air-challenged laboratory ensiling conditions.”
Özdemir (2012) reports that their “results indicated that, potassium sorbate and sodium benzoate in foods have no genotoxic effect (p>0.05). However sodium nitrite has genotoxic effect for every concentrations (p<0.05).”
Caution in Combination
1,4-dinitro-2-methylpyrrole (DNMP) is a mutagenic product formed by the interaction of two common food additives, sorbic acid and sodium nitrite. (shu, 1991) Binstok (1998) found that 1,4-dinitro-2-methylpyrrole formation was precluded when ascorbic acid or cysteine were present.
Nitrite and sorbate also react to form ethylnitrolic acid, another mutagenic product. (ENA). (Pérez-Prio, 2008) (Nanti, 1975)
Sofos (1981) summarised it as follows when he suggested that both DNMP and ethyl nitrolic acid are prevented by the addition of vitamin C. He writes, “Namiki et al. (1981) tested whether the above compounds (ascorbic acid, cysteine) could inhibit the formation of the C-nitro mutagenic compounds. The study consisted of reacting 20 mM sorbic acid with 160 mM sodium nitrite in a pH 3.5 solution at 60°C tor 30 mins. in the presence or absence of various concentrations of ascorbic acid or cysteine. The results showed that a concentration 80 mM ascorbic acid or cysteine eliminated the formation of mutagenic products. Under more realistic conditions (20 mM sorbic acid, 20 mM sodium nitrite) a concentration of 5 or 10 mM ascorbic acid inhibited formation of 1,4-dinitro-2-methyI pyrrole (Y) and ethyl nitrolic acid (ENA), respectively.” (Sofos, 1981)
Potassium Sorbate
It was first discovered by the French in the 1850’s, having been derived from the mountain ash tree. (Mountain Ash Tree, Sorbus aucuparia or Sorbus americana). Today most potassium sorbate is made synthetically.
The antimicrobial properties of sorbic acid were first discovered in the late 1930’s and early 1940’s when it was first patented as a fungistatic agent for foods and food packaging materials (Gooding, 1945). The chemical and antimicrobial properties of the compound were extensively examined during the 1940’s and 1950’s and its use in a variety of food products were initiated (Sofos et al., 1979a; Sofos and Busta,
1981; Luck, 1976). (Sofos, 1981)
It was not until 1974 that serious testing of sorbate as an antibotulinal agent was initiated in meats. (Sohos, 1981)
Sorbic acid is generally considered non-toxic and is metabolised; among other common food preservatives the WHO has set the highest acceptable daily intake (25 mg/kg body weight) for sorbic acid. (FAO)
Sorbic acid and its salts are practically tasteless and odourless in foods when used at reasonable levels (< 0.3 %) and their antimicrobial activity is generally adequate. (FAO)
Sorbates are used for mould and yeast inhibition in a variety of foods including fruits and vegetables, fruit juices, pickles, sauerkraut, syrups, jellies, jams, preserves, high moisture dehydrated fruits, etc. (FAO)
Potassium sorbate, a white, fluffy powder, is very soluble in water (over 50%) and when added to acid foods it is hydrolysed to the acid form. Sodium and calcium sorbates also have preservative activities but their application is limited compared to that of potassium salt, which is employed because of its stability, general ease of preparation and water solubility. (FAO)
According to the USDA’s CFNP TAP Review (2002), It is widely used in the food industry and few substances have had the kind of extensive, rigorous, longterm testing that sorbic acid and its salts have had. It has been found to be non-toxic even when taken in large quantities and breaks down in the body into water and carbon dioxide in the Krebs Cycle. Potassium sorbate is a naturally occurring unsaturated fatty acid and is completely safe with regard to health and have the lowest allergenic potential of all food preservatives. When dissolved in water, potassium sorbate ionizes to form sorbic acid which is effective against yeasts, molds, and select bacteria, and is widely used at 250 ppm to 1000 ppm levels in cheeses, dips, yogurt, sour cream, bread, cakes, pies and fillings, baking mixes, doughs, icings, fudges, toppings, beverages, margarine, salads, fermented and acidified vegetables, olives, fruit products, dressings, smoked and salted fish, confections and mayonnaise. In many food products, sorbate and sodium benzoate are used together to provide greater protection against a wider variety of microorganisms (synergism). Although the minimum inhibatory concentration for many fungi and bacteria is approx. 100 ppm, common usage levels range from 0.5 – 1.0%.”
It is effective up to pH 6.5 but effectiveness increases as the pH decreases. Potassium sorbate has about 74% of the antimicrobial activity of the sorbic acid, thus requiring higher concentrations to obtain the same results that pure sorbic acid provides.
Effective pH
USDA’s CFNP TAP Review (2002) reports that “it is effective up to pH 6.5 but effectiveness increases as the pH decreases. Potassium sorbate has about 74% of the antimicrobial activity of the sorbic acid, thus requiring higher concentrations to obtain the same results that pure sorbic acid provides.” “Maximum level allowable by law is 0.1%. It is important to know that the addition of sodium benzoate and/or potassium sorbate to a food product will raise the pH by approximately 0.1 to 0.5 pH units depending on the amount, pH, and type of product. Additional adjustment of the pH might be needed to keep the pH at a safe level.”
Yigit (2007) concluded that “This study indicates “that potassium sorbate is a suitable preserving agent to inhibit growth of fungi in fermented products of pH near 4.5 regardless levels of NaCl. For products of slightly higher pH, the addition of potassium sorbate is suggested in combination with NaCl.”
Potassium Sorbate and Nitrite
An article apeared in a 1979 publication of the American Chemical Society entitled, “Sorbate passes test as meat preservative”. It reads as follows. “Potassium sorbate has passed its first series of U.S. Department of Agriculture tests for use as a preservative, along with small amounts of sodium nitrite, in meats such as bacon.
A three-month study by USDA’s Food Safety & Quality Service confirms the claims of Monsanto, the only U.S. producer of potassium sorbate, that this compound can be used along with sodium nitrite to provide equal or more effective protection against botulinum toxin than the nitrite alone while producing less nitrosamines.
However, in the study the reduction in nitrosamine production was not so great as had been expected, and several laboratory workers and taste testers reported some adverse reaction to the sorbate-treated
bacon.
The use of nitrites as food preservatives has been of concern to some scientists since the early 1960’s because nitrites are known to react with certain amines that are nearly ubiquitous in the digestive tract to form nitrosamines. These nitrosamines are known to cause cancer in certain laboratory animals and are considered potential human carcinogens.
However, potassium nitrite is an effective way to prevent the production of botulinum toxin, a deadly food poison, in meats. Current meat handling and shipping practices are not considered adequate to protect against this toxin without the aid of an effective preservative.
The USDA study compared bacon prepared without preservatives with two bacons with preservatives. One was prepared according to the current allowed procedure using 120 ppm sodium nitrite. The other used 0.26% potassium sorbate and 40 ppm sodium nitrite.
Three laboratory workers and six of 17 taste-panel members developed reactions to the sorbate-treated bacon. These included slight swelling of the face and hands or mouth and throat irritations. All six tasters who reported adverse reactions were at North Carolina State University. A separate panel of 10 taste testers at USDA’s Beltsville, Md., facility had no ill effects. However, the three lab workers who reported reactions to the sorbate-treated bacon were at Beltsville.
Monsanto says the study confirms four years of company-sponsored testing that shows the sorbate-nitrite treatment is effective in inhibiting botulism. The Monsanto tests did not show any adverse effects. The company says it is sure that further investigation will show that the adverse effects in the USDA test were not caused by sorbate.
Potassium Sorbate and Nitrosamine Formation
Robach (1982) concluded that “Extensive studies involving bacon have shown a major reduction in nitrosamine levels associated with inclusion of potassium sorbate and reduction of sodium nitrite in the curing brine. Simultaneously, the low sodium nitrite/potassium sorbate combinations have maintained or even improved antibotulinal activity in temperature-abused products. In addition, potassium sorbate or sorbic acid have delayed growth and toxin production by Clostridium botulinum in other products including cooked and cured red meat and poultry sausages. The compounds have also been shown to extend the shelf-life and delay growth of other pathogenic microorganisms in several products including bacon; cooked, cured meat sausages; cooked, cured or uncured poultry products; fresh poultry; and other meats, including dry cured and fermented products. Sensory evaluation studies have shown that sorbate levels recommended for use in these products (0.26%) do not have adverse effects on product quality characteristics. Allergic type symptoms attributed to experimental bacon from one study were not linked directly with either potassium sorbate or other formulation ingredients, and all available information does not indicate development of any adverse effects from use of sorbates at recommended levels. In summary, the results of studies conducted in meat products indicate that sorbates deserve consideration as potential alternatives to current formulations or processes involved in the manufacture of processed meat and fresh and processed poultry products.”
Studies published during the late 1970 and early ’80s have demonstrated the efficacy of sorbate in delaying botulinal growth and toxin production in various meat products, especially when combined with low (40-80 ppm) nitrite levels. (Sofosd, 1981)
USDA and the Food & Drug Administration have set up a joint task force to look into the adverse effects before a final decision is made on whether to permit use of potassium sorbate in bacon.”
Guidelines from Codex
-> 1000mg/ kg (1g/kg) FP
– Cooked or fried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds
– Fat emulsions mainly of type oil-in-water, including mixed and/or flavoured products based on fat emulsions
– Fermented vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera) and seaweed products, excluding fermented soybean products of food categories 06.8.6, 06.8.7, 12.9.1, 12.9.2.1 and 12.9.2.3
– Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed pulps and preparations (e.g. vegetable desserts and sauces, candied vegetables) other than food category 04.2.2.5
– Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed purees and spreads (e.g., peanut butter)
-> 1500mg/kg (1.5g/kg) in FP
– Processed comminuted meat, poultry, and game products
-> 2000mg/kg (2g/kg) in FP
– Cured (including salted) and dried non-heat treated processed meat, poultry, and game products in whole pieces or cuts
-> 200mg/kg (0.2g/kg) in FP
– Fermented non-heat treated processed meat, poultry, and game products in whole pieces or cuts
– Heat-treated processed meat, poultry, and game products in whole pieces or cuts
Source:
https://www.fao.org/gsfaonline/groups/details.html?id=10
Recommended for use as a flavour enhancer.
E202 – Potassium sorbate / Flavour enhancer
Additive: E202 – Potassium sorbate
Ingredient: Flavour enhancer
– Products that contain the ingredient Flavour enhancer
Source: https://world.openfoodfacts.org/additive/en:e202-potassium-sorbate/ingredient/en:flavour-enhancer
Suggested declaration: Acidity regulator ( https://en.wikipedia.org/wiki/Acidity_regulator) and Flavour Enhancer.
Sodium Benzoate
Benzoic acid in the form of its sodium salt constitutes one of the most common chemical food preservatives. Sodium benzoate is a common preservative in acid or acidified foods such as fruit juices, syrups, jams and jellies, sauerkraut, pickles, preserves, fruit cocktails, etc. Yeasts are inhibited by benzoate to a greater extent than are moulds and bacteria. (FAO)
-> 1000mg/kg (1g/kg) in FP
– Cooked or fried vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), and seaweeds
– Cured (including salted) and dried non-heat treated processed comminuted meat, poultry, and game products
– Cured (including salted) and dried non-heat treated processed meat, poultry, and game products in whole pieces or cuts
– Cured (including salted) and dried non-heat treated processed comminuted meat, poultry, and game products
– Fat emulsions mainly of type oil-in-water, including mixed and/or flavoured products based on fat emulsions
– Fermented vegetables (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera) and seaweed products, excluding fermented soybean products of food categories 06.8.6, 06.8.7, 12.9.1, 12.9.2.1 and 12.9.2.3
– Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed purees and spreads (e.g., peanut butter)
-> 3000mg/kg (3g/kg) in FP
– Vegetable (including mushrooms and fungi, roots and tubers, pulses and legumes, and aloe vera), seaweed, and nut and seed pulps and preparations (e.g. vegetable desserts and sauces, candied vegetables) other than food category 04.2.2.5
Source: https://www.fao.org/gsfaonline/groups/details.html?id=162.
Use: colour enhancer
Caution
Do not use ascorbic acid. Coming into reaction with ascorbic acid (vitamin C, the additive E300), sodium benzoate can form benzol, which is a potent carcinogen. (https://proe.info/additives/e211)
As an alternative, consider the use of Natamycin.
References
American Chemical Society article. Sorbate passes test as meat preservative. Chem. Eng. News 1979, 57, 32, 7; Publication Date: August 6, 1979; https://doi.org/10.1021/cen-v057n032.p007; 1979 American Chemical Society
G Binstok, C Campos, O Varela, L.N Gerschenson, Sorbate–nitrite reactions in meat products, Food Research International, Volume 31, Issue 8, 1998, Pages 581-585, ISSN 0963-9969, https://doi.org/10.1016/S0963-9969(99)00031-9. (https://www.sciencedirect.com/science/article/pii/S0963996999000319)
Knicky M, Spörndly R. Short communication: Use of a mixture of sodium nitrite, sodium benzoate, and potassium sorbate in aerobically challenged silages. J Dairy Sci. 2015 Aug;98(8):5729-34. doi: 10.3168/jds.2015-9332. Epub 2015 May 28. PMID: 26026758.
Mitsuo Namiki & Tsuneo Kada (1975) Formation of Ethylnitrolic Acid by the Reaction of Sorbic Acid with Sodium Nitrite, Agricultural and Biological Chemistry, 39:6, 1335-1336, DOI: 10.1080/00021369.1975.10861781
Özdemir H, Turhan AB, Arıkoğlu H. Investigation of Genotoxic Effects of Potassium Sorbate, Sodium Benzoate and Sodium Nitrite. Eur J Basic Med Sci. 2012;2(2):34-40. https://doi.org/10.21601/ejbms/9177
Sohos, J. N. (1981) Nitrite, Sorbate and pH Interaction in Cured Meat Products. 34th Reciprocal Meat Conference
M. Teresa Pérez-Prior, José A. Manso, Rafael Gómez-Bombarelli, Marina González-Pérez, M. Pilar García-Santos, Emilio Calle, M. Cruz Caballero, Julio Casado. (2008) Reactivity of Some Products Formed by the Reaction of Sorbic Acid with Sodium Nitrite: Decomposition of 1,4-Dinitro-2-methylpyrrole and Ethylnitrolic Acid. J. Agric. Food Chem. 2008, 56, 24, 11824–11829, Publication Date: November 18, 2008, https://doi.org/10.1021/jf802822y; American Chemical Society
Robach MC, Sofos JN. Use of Sorbates in Meat Products, Fresh Poultry and Poultry Products: A Review 1. J Food Prot. 1982 Mar;45(4):374-383. doi: 10.4315/0362-028X-45.4.374. PMID: 30866345.
Shu YZ, Kingston DG, Van Tassell RL, Wilkins TD. Metabolism of 1,4-dinitro-2-methylpyrrole, a mutagen formed by a sorbic acid-nitrite reaction, by intestinal bacteria. Environ Mol Mutagen. 1991;17(3):181-7. doi: 10.1002/em.2850170307. PMID: 2022195.
Yen Thi Hai Hoang and An Thi Lam Vu. (2016) Sodium Benzoate and Potassium Sorbate in Processed Meat Products Collected in Ho Chi Minh City, Vietnam. Article in International Journal on Advanced Science Engineering and Information Technology · July 2016. Vol.6 (2016) No. 4, ISSN: 2088-5334
USDA’s CFNP TAP Review (2002):
Yigit, A. and Korukluoglu, M.. (2007) The effect of potassium sorbate, NaCl and pH on the growth of food spoilage fungi. Annals of Microbiology volume 57, pages209–215 (2007)