Factors That Influence the Acrylamide Content of Heated Foods

Abstract

Our finding that acrylamide is formed during heating of food initiated a range of studies on the formation of acrylamide. The present paper summarizes our follow-up studies on the characterization of parameters that influence the formation and degradation of acrylamide in heated foods. The system designed and used for studies of the influence of added factors was primarily homogenized potato heated in an oven. The net content of acrylamide after heating was examined with regard to the following parameters: heating temperature, duration of heating, pH and concentrations of various components. Higher temperature (200 degrees C) combined with prolonged heating led to reduced levels of acrylamide, due to elimination/degradation processes. At certain concentrations, the presence of asparagine or monosaccharides (in particular fructose, glucose and glyceraldehyde) was found to increase the net content of acrylamide. Addition of other free amino acids or a protein-rich food component strongly reduced the acrylamide content, probably by promoting competing reactions and/or covalently binding of formed acrylamide. The pH-dependence of acrylamide formation exhibited a maximum around pH 8; lower pH enhanced elimination and decelerated formation of acrylamide. In contrast, the effects of additions of antioxidants or peroxides on acrylamide content were not significant. The acrylamide content of heated foods is the net result of complex reactions leading to both the formation and elimination/degradation of this molecule.

Effect of lactic acid fermentation of lupine wholemeal on acrylamide content and quality characteristics of wheat-lupine bread

“…Rydberg et al (2005) reported that the higher temperature (200 C) combined with prolonged heating led to reduced levels of acrylamide, due to elimination/ degradation processes. Increased protease activity of LAB may result in an enhanced release of amino acids from proteins.…”

“…In particular, L. sakei and spontaneous fermentation decreased the pH by 35.9% at the end of fermentation; while the Pedioccocus strains were found to be weaker acidifiers decreasing the pH by 32.2%. Rydberg et al (2005) reported that the pH-dependence of acrylamide formation exhibited a maximum of around pH 8; a lower pH enhanced the elimination and deceleration of acrylamide. Addition of a protein-rich food component reduces the acrylamide content probably by promoting competing reactions and/or covalently binding of formed acrylamide (Rydberg et al, 2005).…”

“…Rydberg et al (2005) reported that the pH-dependence of acrylamide formation exhibited a maximum of around pH 8; a lower pH enhanced the elimination and deceleration of acrylamide. Addition of a protein-rich food component reduces the acrylamide content probably by promoting competing reactions and/or covalently binding of formed acrylamide (Rydberg et al, 2005). Our previous study showed that acrylamide formation in bread was slightly affected by LAB amylase activity excreted in extruded rye sourdough, while fermentation with high proteolytic LAB significantly decreased the concentration of acrylamide in bread (Bartkiene et al, 2013).…”

“…Protein breakdown products, peptides and amino acids may represent precursors for acrylamide formation during the heating of foods containing the reducing sugars (Lingnert et al, 2002;Rydberg et al, 2005;Zyzak et al, 2003).…”

Technological Strategies to Reduce Acrylamide Levels in Heated Foods

“…Acrylamide formation is affected by many factors, such as precursors (i.e., reducing sugar and asparagine) concentration, pH, water content and activity, physical state of the food, and process parameters, mainly represented by the heating time and temperature [12, 28,48,57,60,62,69,70,77]. For instance, acrylamide formation is favored by a high heating temperature and time, as well as pH values, a relatively low water content and activity.…”