The Canon of Potato Science: 49. Acrylamide
Published online: 14 May 2008 # EAPR 2008
What is it? Acrylamide is an odourless and colourless crystalline solid with a melting point of 84.5 °C that is formed from the hydration of acylonitrile. Such a small compound is soluble in water, acetone, and ethanol, has ahigh mobility in soil and groundwater and is biodegradable. Polyacrylamide polymers and copolymers are used in the paper and textile industries, as flocculants in the treatment of waste water, as soil conditioners, in ore processing and in the cosmetics industry. Heat, light and outdoor environmental conditions, but not pH, promote depolymerization of polyacrylamide to acrylamide. The observationthat acrylamide used as a sealing adjuvant in tunnel construction in Sweden was responsible for adverse health effects in exposed workers led researchers to an association of acrylamide with foods. Before its discovery in foods, acrylamide was known as an industrial chemical and a component of cigarette smoke. Acrylamide is a known carcinogen substance in experimental animals, that occurs incarbohydrate-rich foods as a result of cooking methods at high temperatures. On the other hand, acrylamide has been classified as probably carcinogenic in humans. In April 2002, Swedish researchers shocked the food safety world when they presented preliminary findings of acrylamide in some fried and baked foods, most notably potato crisps and French fries, at levels of 30–2300 μg kg−1. As acrylamidehas not been detected in unheated or boiled foods, it was considered to be formed during heating at high temperatures. They attributed this fact to the higher temperatures reached in Maillard non-enzymatic browning reactions required for desirable colour, flavour and aroma production. The data published so far indicate that a temperature > 100 °C is required for acrylamide formation. Some authorshave shown that acrylamide was formed by heating above 120 °C certain starch-based
F. Pedreschi (*) Departamento de Ciencia y Tecnologia de Alimentos, Universitad de Santiago de Chile, Av. Ecuador 3769, Santiago de Chile, Chile e-mail: email@example.com
Potato Research (2007) 50:411–413
foods, such as potato crisps and French fries. French fries and potato crisps exhibitrelatively high values of acrylamide. Values of 424 μg kg−1 and 1739 μg kg−1, respectively, have been reported.
Why is it Important in Potato Science? Reports of the presence of acrylamide in fried potatoes have caused worldwide concern because this compound has been classified as probably carcinogenic in humans with significant toxicological effects, namely neurotoxic and mutagenic ones. Moreover,recent epidemiological studies by the University of Maastricht in the Netherlands, supported by the Dutch Food Safety Agency, indicated a positive association between dietary acrylamide and the risk of certain types of cancer. Some researchers have observed increased risks of endometrial and ovarian cancer with increasing dietary acrylamide intake, particularly among never smokers. Risk of breastcancer was not associated with acrylamide intake. For those reasons, currently, a substantial body of research has been carried out world-wide to build greater understanding of how acrylamide is formed in fried potatoes, what the risks are for consumers and how to reduce occurrence levels. The Maillard reaction is the principal mechanism of acrylamide formation in fried potatoes. For instance, infried potatoes, acrylamide can be released by the thermal treatment of certain amino acids such as asparagine, particularly in combination with reducing sugars (glucose and fructose), and of early Maillard reaction products (N-glycosides). Besides, fried potato colour is the result of Maillard, non-enzymatic browning reactions that depend on the superficial reducing sugar content, the temperature...