| Cottonseed oil, hydrogenated soybean oil and hydrogenated canola oil were subjected to high temperatures (350°F) for 8 hours per day and 6 batches of French fries were fried per day. French fries were weighed prior to frying, cooked for 5 minutes, allowed to drain, and reweighed. Oil was not replenished, filtered once per day, and weighed before and after frying. Oil and French fries were evaluated to determine color, fatty acid profiles, trans fatty acids, crude fat, and moisture. Analytical tests included total polar materials, measured on the french fries; iodine values, peroxide values, p-anisidine values, free fatty acids and totox values, measured on the oil.; No significant differences were found between oil types for oil loss, French fry loss, color, moisture, and crude fat. Iodine values for all three oil types were significantly different. Both canola oil and soybean oil had significantly lower iodine values than cottonseed oil due to hydrogenation. Free fatty acid values were not significantly different for oil type. Cottonseed oil was significantly different from canola oil and soybean oil for peroxide value, p-anisidine value and totox value. Cottonseed oil had higher values, indicating an increased presence of primary and secondary oxidation. However, as days of frying increased, values for all three oils trended closer together. There were no significant differences between total polar materials for french fries cooked in all three oils. Fatty acid profiles for both the french fries and the oil remained relatively stable as frying days increased. All of the analytical tests indicated that the three oil types did not reach a highly deteriorated state. Cottonseed oil was significantly lower in trans fatty acids for both the oil and the french fries. Cottonseed oil appeared to be as stable as canola oil and soybean oil, however a much larger extent of stress would need to be generated in order to determine a comparable relationship. In terms of health effects, the french fries cooked in cottonseed oil were slightly higher in saturated fatty acids, but remarkably lower in trans fatty acids than canola oil and soybean oil. |
