Effect of Deep Frying on Fatty Aid Composition and Sterol Content of Grape Seed Oil

Grape seed oil is important to human health due to its very pleasant taste, odor, as well as its high nutritional values. Consumption of the grape seed oil in the diet has been increasing in recent years. Long periods of heating will deteriorate the oil and fried products due to oxidative and hydrolytic changes and reactions. Therefore, accurate control of the frying processes and changes are quiet essential.

In this study, the effects of deep frying at 180 °C (24 and 48 hours) on some chemical characteristics of grape seed oil namely sterol profile and fatty acid composition have been studied using chromatography techniques.

The results indicated that, the predominant fatty acid was linoleic acid, and by increasing the heating period, more unsaturated fatty acids namely linoleic acid was decreased due to oxidation. The phytosterols study showed that beta-sitosterol was the predominant phytosterol and deep fat frying did not affect its concentration.

Due to the high concentration of linoleic acid and beta-sitosterol in grape seed oil, it might be stated that the oil has a high nutritional value, but considering the changes during frying it might not be recommended for frying practices.