Browsing by Subject "paahtaminen"

Acrylamide is a small molecular compound, which has been labeled as a probable carcinogen in humans. Acrylamide cannot be found natively in food raw material. It is formed when a carbohydrate and protein rich matrix is heated in temperatures above 120 °C. Foodstuff with high risk of containing higher levels of acrylamide are bread and bakery products, potato based foods and coffee. The most critical parameters for the formation of acrylamide are process temperature, the duration of the heating and moisture of the food matrix. A dry matrix, heated in high temperatures for longer periods gives high concentrations of acrylamide. The European Commission has given an opinion on the indicative values of acrylamide content in various foodstuffs. The indicative values are not safety limits for intake, but meant to indicate the need for action. The literature review of this thesis focused on the chemical properties of acrylamide and factors impacting the formation. The occurrence of acrylamide in food and means of mitigation were also reviewed. In the experimental part of this thesis the acrylamide content of rye bread and mämmi were studied. The effect of toasting on the acrylamide content of the rye bread was also studied. The formation of acrylamide during toasting was explained by measurement of moisture and amino acid content of the bread. The samples used in the experimental toasting study were four commercially available sliced rye breads with a wheat toast as reference material. All breads were toasted 0 – 210 seconds in a regular toaster. Method of acrylamide analysis was high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The acrylamide content varied between the untoasted rye breads, 50 – 350 µg/kg. With the longest toasting time the content rose to 50 – 830 µg/kg. In the European Commission indicative values there is no equivalent to the rye bread. The closest product group is rye crisps, with and indicative value of 450 µg/kg. All the studied untoasted rye bread acrylamide contents fall below this value. When toasted, only one of the rye breads exceeded the indicative values with the longer frying times. The regular toast had levels between 0 and 210 µg/kg respectively. The commission indicative value for wheat based bread is 80 µg/kg was exceeded only with longer toasting times. The mämmi contained 100 µg/kg of acrylamide. For mämmi there are no indicative values.