Impact of the reducing sugars on the relationship between acrylamide and Maillard browning in French fries

The relationship between acrylamide content and Maillard browning in French fries was studied as a function of different glucose/fructose ratios in the raw product using several colour measurement methods. An exponential correlation was found between acrylamide formation and surface colour, as evaluated by the parameters a*, delta E and Agtron. As a consequence, small differences in product colour could result in more pronounced differences in acrylamide contamination. This relationship however appeared to be dependant upon the glucose/fructose ratio of the raw material. An excess of fructose compared to glucose stimulated acrylamide formation to a higher extent than Maillard browning. The opposite effect was established with an excess of glucose. In addition, a linear relationship was found between the absorbance of aqueous French fries extracts and acrylamide content, which moreover appeared to be less affected by the addition of extra reducing sugars prior to frying. To predict acrylamide formation, sugar analysis however remains an important instrument and is complementary to surface colour measurement.