Influence of Nitrogen and Potassium Supply on Contents of Acrylamide Precursors in Potato Tubers and on Acrylamide Accumulation in French Fries

ABSTRACT

Fried potato products may accumulate substantial amounts of acrylamide due to high precursor contents, namely reducing sugars and asparagine. In a two-factorial experiment increasing N supply, increased the contents of reducing sugars in most cases, and resulted in higher contents of free amino acids. α -amino-N, which was tightly correlated with the contents of free amino acids, can be regarded a suitable rapid test for free asparagine for a given variety. Increasing K addition always raised the citrate contents, but lessened the contents of reducing sugars. Selected treatments were processed into French fries. Highest acrylamide contents were observed in tubers grown with high N and inadequate K supply, which also contained the highest contents of precursors. The experiment clearly demonstrates that nutrient supply has significant impact on the contents of acrylamide precursors and thus for the acrylamide formation during frying.

Keywords:

• acrylamide
• amino acids
• nitrogen
• potassium
• potato
• reducing sugars
• Solanum tuberosum ssp. tuberosum L.

ACKNOWLEDGEMENTS

Dedicated to Prof. Dr. Burkhard Sattelmacher, who passed away on November 21, 2005. The authors are grateful to Dr. Reiner Krähmer for his advice and to Stephanie thor Straten, Regine Epbinder and Bijan Kawiani for help and assistance during the course of the experiments and the analysis.