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A number of parameters linked to storage of potatoes were evaluated with regard to their potential to influence the acrylamide formation in French fries. Acrylamide, which is a potential human carcinogen, is reported to be formed during the frying of potatoes as a result of the reactions between asparagine and reducing sugars. This study was conducted using three potato varieties (Bintje, Ramos, and Saturna) typically used in Belgium, The Netherlands, and the northern part of France for French fry and crisp production. Saturna, mainly used in crisp production, appeared to be the least susceptible for acrylamide formation during frying. Especially storage at low temperatures (4 degrees C) compared to storage at 8 degrees C seemed to enhance acrylamide formation due to a strong increase in reducing sugars caused by low-temperature storage. Because of the reversible nature of this physiological reaction, it was possible to achieve a significant reduction of the reducing sugars after a reconditioning of the cold-stored potatoes for 3 weeks at 15 degrees C. All changes in acrylamide concentrations could mainly be explained by the reducing sugar content of the potato (R2 = 0.84, n = 160). This means that, by ensuring a low reducing sugar content of the potato tuber, the risk for acrylamide formation will largely be reduced. Finally the use of a sprout inhibitor did not influence the composition of the potato, and thus acrylamide formation was not susceptible to this treatment.

The influence of the refining process on the distribution of free and esterified phytosterols in corn, palm, and soybean oil was studied. Water degumming did not affect the phytosterol content or its composition. A slight increase in the content of free sterols was observed during acid degumming and bleaching due to acid-catalyzed hydrolysis of steryl esters. A significant reduction in the content of total sterols during neutralization was observed, which was attributed to a reduction in the free sterol fraction. Free sterols probably form micelles with soaps and are transferred into the soapstock. The steryl ester content remained constant during all neutralization experiments, indicating that hydrolysis of steryl esters did not take place during neutralization. During deodorization, free sterols are distilled from the oil, resulting in a gradual reduction in the total sterol content as a function of the deodorization temperature (220-260°C). A considerable increase in the steryl ester fraction was found during physical refining, probably owing to a heatpromoted esterification reaction between free sterols and FA.Paper no. J10068 in JAOCS 79, 947-953 (October 2002).