Effect of Food Emulsions on the Cytotoxicity of 3-chloropropane-1,2-diol Esters

Abstract

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.