A novel oleogel-in-oleogel system with tailorable digestibility through kinetic confinement of the oil

Saturated fats have unique structural properties that make them invaluable for the food industry; however, they have a weak effect on satiety, leading to passive overconsumption which contributes to cardiovascular disease, obesity and related health issues. Oleogels rich in unsaturated fatty acids have been explored as their replacement, potentially reducing cardiovascular disease risk. However, most oleogels still maintain a high caloric content, failing to provide a solution to the problem of obesity. To address the challenge of substituting saturated fats while also reducing caloric content, we developed a novel oleogel-in-oleogel system with partial indigestibility. The inner oleogel, gelled by ethylcellulose – a cellulose derivative with gut effects similar to dietary fibre –, passes through the intestine largely unaltered, while the outer oleogel is digestible and gelled by conventional gelators like candelilla wax, monoglycerides, and stearic acid. We compared this system to conventional multi-component oleogels with the same composition. Our results showed that the oleogel-in-oleogel maintained its melting profile after the incorporation of the oleogel beads. The kinetic confinement of the oil allowed for the tailoring of the in vitro digestibility of the oleogel, reducing it by 17 %–26 % compared to the control oleogels, and up to 33 % compared to single-component oleogels. This oleogel-in-oleogel system is therefore capable of delivering fewer calories than fats and most oleogels, while still delivering essential fatty acids. These promising findings pave the way for developing oleogel-based systems with tailorable digestibility, aiming to replace saturated fats and potentially serve as a tool for controlling caloric intake and bodyweight. • Developed a novel oleogel-in-oleogel system for tailoring lipid digestibility. • Developed a novel piece of equipment to prepare ethylcellulose oleogel beads. • Ethylcellulose beads act as fillers, decreasing oil digestibility by up to 33 %. • The type of outer oleogel affects digestibility. • The system offers a promising fat substitute with controlled digestibility.