Enhancing Repeated Frying Stability of Soybean Oil by Blending With Beef Tallow.

Frying can bring desirable flavor and crispness to food, with frying oil performance being crucial for product quality and safety. This study investigated the effects of blending beef tallow (BT) with soybean oil (SO) on the oxidative stability, sensory quality, and safety profile of frying oil subjected to repeated use. Five blends with saturated fatty acid (SFA) levels ranging from 18.95% to 28.82% were evaluated. Increasing the BT proportion significantly improved frying stability. Compared to pure SO, the blend with the highest SFA content (S5, 28.82% SFA) showed the greatest reduction in oxidation indices, including a 38.2% decrease in acid value and a 30.0% decrease in peroxide value. After 20 frying cycles, BT/SO blends also reduced harmful compounds such as benzo[a]pyrene (by 10.6%-34.1%) and total polar compounds (by 17.5%-27.1%). Sensory evaluation indicated that blends such as S4 (26.55% SFA) suppressed sour odor and enhanced buttery and roasted notes, while excessive BT introduced an undesirable cowy odor. Fatty acid analysis confirmed that BT blending slowed polyunsaturated fatty acid degradation and trans fatty acid formation. In conclusion, moderate BT addition, particularly at approximately 26.55% SFA, effectively improves the oxidative stability and flavor quality of repeatedly used frying oil. PRACTICAL APPLICATIONS: This study offers a practical blending strategy for the food industry to enhance the performance of repeatedly used frying oils. The incorporation of an appropriate amount of BT into vegetable oil can effectively improve oil stability. Manufacturers can extend oil service life, reduce harmful compound formation, and maintain desirable sensory attributes of fried foods. These benefits make the approach suitable for both large-scale food production and small-scale foodservice operations.