Characterization of grape seed oil from different grape varieties (Vitis vinifera)

In this work, oil obtained from seeds of different red grape varieties, grown in the Autonomous Regions of Castilla-La Mancha and Murcia (Spain), was characterized by determining physicochernical and sensory quality parameters, stability, and the composition in fatty acids and sterols. The physicochernical quality parameters (free acidity, peroxide index, K-270 and wax) scored high (meaning low quality) compared with virgin olive oils, while the negative sensory attributes stood out over the positive ones. Therefore, the oil was not considered suitable for table use without undergoing a refining process. The samples showed high linoleic and low linolenic acid contents, while beta-sitosterol was the main sterol found. Drying grape seeds with hot air before extraction gave higher physicochemical quality, total phenolic content and stability, and lower wax content in comparison to air-drying of seeds. The drying process affected the sterol composition but not the fatty, acid composition.