High dry matter, edible energy and protein content of potato make it nutritionally a superior vegetable as well as staple food. It is reported that Frozen French fries and chips share unit operations in the potato processing industry of 30% and 12% respectively.
Potatoes with a high solids content (20-22%) are preferred in the processing of chips and French fries because of their better texture, higher yield and lower oil absorption in the finished product (Lisinska, 1989 ).
The content of reducing sugars is closely related to the final color of fried potatoes (Singh R. D., 1976), as low reducing sugar content minimizes the color produced by Millard or non-enzymatic browning reactions during frying (Lisinska, 1976).
Potato chips are very thin slices, 1.27-1.78 mm, are deep fried in a continuous fryer, where they remain from 1.5-3 minutes at 170°-190°C, until the moisture level is less than 2% and have a final oil content of 33-38%.
On the other hand the French-fries represent a composite structure formed by two regions: (i) an external dehydrated and crispy region where oil is located; and (ii) a humid and cooked core region free of oil. The external crust is very similar to the structure of a fried potato slice or potato chip (Pedreschi, 2002). The final oil and moisture content of French – fries is about 15% and 38%, respectively (Aguilera,2000;Saguy,2003).
Nowadays the consumers are becoming health conscious and therefore these deep-fat fried products need to be processed in a manner which fulfils the sensory and health aspects of the consumer. Hence, in order to make the products healthy, the property of the fried product to take up oil at the time of frying or cooling period has to be managed.
Acrylamide is a toxic compound that is primarily formed during frying, and the blanching step prior to frying is an important step in reducing the formation of this compound.
Recent studies have shown that reducing sugar content by blanching or soaking can reduce acrylamide concentrations in potato chips by approximately 60% (Haase, Matthaus, & Vosmann, 2003), (Pedreschi, Kaack, & Granby, 2006).
Blanching is a treatment carried out in the temperature range of 65 to 90°C, resulting in inactivated enzymes.
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