Hazelnut oil is a significant edible oil with positive effects on human health. This study aimed to integrate hazelnut oil, which is known for its cardiovascular benefits, into nanoemulsion technology for the first time as an innovative conception, to maintain its stability against environmental conditions, and to benefit more by making it more bioaccessible. Polysorbate 80 and whey protein isolate (WPI) were used to stabilize the nanoemulsions. In this way, we aimed to show that WPI, a natural emulsifier, could be an alternative to the synthetic Polysorbate 80 emulsifier known for its high emulsification ability to stabilize hazelnut oil emulsions. The emulsions, formed by using a 2% (wt/wt) emulsifier and passed through a microfluidizer five times at 96.5 MPa pressure provided the small particle size (d32) as 296 ± 7.76 nm and 216 ± 1.78 nm for the WPI and Polysorbate 80‐stabilized samples, respectively. Polysorbate 80‐stabilized nanoemulsions were more physically stable under different pH, temperature, and ionic strength conditions compared with WPI‐stabilized nanoemulsions. Finally, the fates of the emulsions were investigated under a simulated in vitro digestion system. The increase in droplet sizes during the gastric phase was to a higher extent for the WPI‐stabilized nanoemulsions (d32 = 5.500 ± 0.60 μm) compared with Polysorbate 80‐stabilized emulsions (d32 = 1.069 ± 0.09 μm). Although hazelnut nanoemulsions stabilized with Polysorbate 80 showed higher physical stability, it was determined that WPI would also be successful in producing stable hazelnut oil‐in‐water emulsions, exhibiting FFA (%) values of 88%–90.5% in the small intestine.

3-Chloropropane-1,2-diol (3-MCPD) esters are food processing contaminants, and are known to be potentially carcinogenic. The main purpose of this study was to determine whether the emulsion technique increases the absorption of this contaminant, and to develop strategies to reduce their absorption. 3-MCPD ester contents in edible oils (hazelnut, walnut, sunflower, soybean, corn, and olive oil) were determined. Refined olive oil contained the highest 3-MCPD ester level (1.7749 ± 0.1262 mg/kg). Then, emulsions (fine, medium, coarse) were prepared with 0.15-2% emulsifier (whey protein isolate) and 10% oil using microfludizier at 3-10 kpsi pressure. The free fatty acid release was investigated using an in vitro digestion model, and the bioaccessibility was calculated. Methylthiazole tetrazolium (MTT) cell viability method was used to perform toxicity tests. The zeta potential and droplet size of the Samples were measured after each digestion phase. The emulsion with the smallest particle size (389 nm) resulted in the highest release of free fatty acid (85.26%) during small intestinal phase. Fine emulsions also resulted in the highest 3-MCPD ester bioaccesibility (95%). During in vitro digestion, droplet size increased at stomach phase for all emulsion types (Figure 1). When an indigestible oil, such as lemon oil, was added to the oil phase of the fine emulsion (up to 30%), the release of free fatty acid decreased by up to 30% as expected and bioaccessibility decreased by up to 45%. The micelle phase of the fine and medium emulsion had a toxic effect on the fibroblast cell line (Figure 2). When the particle size increased and lemon oil was added to the oil phase of the emulsion, the percent viability increased. Briefly, there are two ways to reduce the absorption of 3-MCPD esters in food emulsions: producing emulsions with larger particle size, or adding indigestible oil to the oil phase.