Measurement results, quarks and soy sauces


Biohit has carried out new measurements of acetaldehyde concentrations in quarks and soy sauces. Acetaldehyde is a substance with apple flavor that is especially rich in food prepared with a fermentation process such as alcohol beverages, vinegar and dairy products. Research agency IARC has classified acetaldehyde as a Group I human carcinogen in 2009.

Materials and Methods

Biohit analyzed the acetaldehyde concentration in 32 different quarks and 13 different commercial soy sauces. Quark products were randomly selected in different grocery stores in the capital area of Finland and soy sauces are partly from same area, partly from Boston area in the United States. The samples were selected randomly from different stores. For soy sauces, a single bottle from each brand was included in analysis, whereas from each quark brand, one or two goblets were analyzed. Each measurement was made in duplicate.The analysis performed using gas-chromatography method that has been validated by Biohit (see below “Measurements”).


According the measurements, in quarks the measured concentrations ranged from 0 to 177 µM (0-17,8 mg/l). In soy sauces, the acetaldehyde concentration ranged from 45 to 199 µM (2-8,8 mg /l).

Table 1. Acetaldehyde concentrations in the yoghurts and beers analyzed by a gas chromatography. 

 No. of analyzed productsLowest observed acetaldehyde concentration µM (mg/l)Highest observed acetaldehyde concentration µM (mg/l)
Quark320 (0)177 (7,8)
Soy sauce1245 (2)199 (8,8)


The analysis was undertaken to tentatively investigate the acetaldehyde concentrations in quarks and soy sauces. The brands were selected randomly in various grocery stores, and included both domestic and foreign brands.In results it is significant that both product groups had high acetaldehyde concentrations on the average. Quark products show high concentrations of acetaldehyde due to the leaven used in the production.
CEO Semi Korpela, Biohit Oyj: “Quarks are commonly marketed as contribution to health, but the results from acetaldehyde measurements are eye-opening. Product manufacturers should openly in product data sheet mention the acetaldehyde concentration and let consumers themselves decide about the possible exposure to acetaldehyde.”


Methods and Equipment:Head-space gaschromatography adopted from Pikkarainen et al. (1979) and Jokelainen et al. (1994), as well as NIOSH ((National Institute of Occupational Health and Safety) (1994) methods.Clarus 500 Gaschromatoraph, BAC-2 capillary column, TurboMatrix HS-110 sampler (PerkinElmer Finland, Turku).
Calibrators and Controls:Acetaldehyde, CAS 75-07-0 (Supelco, Bellefonte, PA, USA, cat# 506788), purity 99,9%. The samples were prepared by weighing. Method Validation:According to Biohit’s quality system (ISO 9001:2008, ISO13485:2003).The validation was performed, when applicable, according to following standards and directives (the method is not accreditated):• Guidance for Industry. Q2B Validation of Analytical Procedures: Methodology. ICH November 1996.• 2002/657/EC Commission Decision of 12 August 2002, implementing Council Directive 96/23/EC concerning the performance of analytical methods and the interpretation of results (Text with EEA relevance).


Jokelainen K, Roine RP, Väänänen H, Färkkilä M, Salaspuro M. In vitro acetaldehyde formation by human colonic bacteria. Gut 1994; 35: 1271-4.NIOSH Manual of Analytical Methods (NMAM), Fourth Edition. ALDEHYDES, SCREENING: METHOD 2539, Issue 2, dated 15 August 1994 – 10 pages.Pikkarainen PH, Salaspuro MP, Lieber CS.A method for the determination of “free” acetaldehyde in plasma. Alcohol Clin Exp Res. 1979 Jul;3(3):259-61. 
Read more: Specify the acetaldehyde concentrate in foodstuff with Biohit laboratory

Acetaldehyde Group I human carcinogen

In October 2009, the International Agency for Research on Cancer (IARC), which forms part of the World Health Organization, classified acetaldehyde included in and generated endogenously from alcoholic beverages as a Group I human carcinogen. Acetaldehyde belongs to the same risk class as, for example, asbestos and tobacco.Specific microbes (bacteria and yeasts) in the gastrointestinal tract are the most important source of acetaldehyde exposure to the human body. These microbes produce acetaldehyde from alcohol and, in certain circumstances, from sugar. Unlike the liver, the microbes and the intestinal mucosa cannot remove the acetaldehyde, and due to the effect of alcohol, an abundance of acetaldehyde accumulates in the saliva and elsewhere in the gastrointestinal tract. Acetaldehyde is a substance that accumulates in the body from several sources, continuous exposure to it thereby severely increasing the risk of cancer to various organs.
Source: IARC, Secretan et al (2009)
Read more: Research information on Acetium