Rapeseed Oil-Based Oleogels With Sunflower Wax and Monoacylglycerols as Alternatives to Conventional Frying Fats and Oils for Deep-fat Frying of French Fries

Rapeseed oil-based oleogels structured with 5% sunflower wax (SFW) and 5% monoacylglycerols (MG), respectively, were used for deep-fat frying French fries to optimize surface properties in terms of their oily perception. The resulting oleogels were compared to rapeseed oil. In a stress test, oleogel SFW was comparable to rapeseed oil after 20 frying cycles in total polar compounds (36.1 g/100 g, 34.0 g/100 g for rapeseed oil), polymerized triacylglycerols (PTAGs) (13.6%, 14.4% for rapeseed oil), and color. Oleogel MG resulted in higher contents of total polar compounds (40.9 g/100 g) and PTAGs (19.9%). Additionally, oleogel MG was less firm than oleogel SFW. This result was confirmed by rheology. Comparison of the sensory quality of the French fries showed that the products fried in oleogels had less oily haptic properties and a less oily mouthfeel. Lightness, aroma perception, and crispness were not significantly different to the rapeseed oil. Color and texture showed little to no differences between the samples. The total fat content of the French fries showed lower values for products fried in oleogel MG (9.2 g/100 g), whereas products fried in rapeseed oil (13.2 g/100 g) or oleogel SFW (12.1 g/100 g) showed no significant difference.

Practical Applications: Deep-fat frying is one of the most popular methods of preparing food. One problem is that the deep-frying media used either contain high levels of saturated fatty acids, which are unfavorable in terms of nutritional physiology, or that they are liquid vegetable oils that oil out during the storage of deep-fried food. Therefore, the use of so-called oleogels based on rapeseed oil could be a favorable alternative, which combines the techno-functional properties of solid fats with the nutritional–physiological advantages of liquid rapeseed oil. This article shows as an example that the application of oleogels for the preparation of French fries results in products with advantages regarding oily haptics and oily mouthfeel without having disadvantages for most other parameters describing the frying oil quality.