The effect of frying on some qualitative characteristics of grape seed oil

Grape seed oil is the vegetable oil which has essential fatty acids such as linoleic acid and antioxidant compounds such as tocopherols and polyphenols. Production and consumption of this oil has gained attention in recent years. Using this oil in diet due to its nutritional properties can have a significant role in health. Therefore، in this research، the effect of frying on some qualitative properties of grape seed oil has been investigated. For this purpose، grape seed oil was heated at 180 ºC for 0 (control)، 30، 60 and 90 minutes. Then chemical analysis such as acidic value، peroxide، anizidin value، the amount of tocopherol، polyphenols، carotenoides، chlorophyll and oxidation stability were carried out on the oil. The results showed that the acidic value was increased significantly by heating. The peroxide value first was increased and then was decreased significantly by heating. The anizidin value increased significantly as the peroxide value was decreased. The amount of tocopherols، polyphenols، carotenoids and chlorophyll were decreased significantly during the heating process. The results of oxidation stability showed that the grape seed oil has not high oxidation stability against heating.