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Impact of Titanium Dioxide on the Bioaccessibility of β-Carotene in Emulsions with Different Particle Sizes

Li, Qian, Fu, Yinxin, Liu, Chengmei, Zhang, Ruojie, Zhang, Zipei, McClements, David Julian
Journal of agricultural and food chemistry 2018 v.66 no.35 pp. 9318-9325
Raman spectroscopy, artificial colors, beta-carotene, beverages, bioactive compounds, bioavailability, digestion, emulsions, food industry, free fatty acids, functional foods, gastrointestinal system, ingredients, lipophilicity, models, nanoparticles, particle size, solubilization, titanium dioxide
Commercial, titanium dioxide (TiO₂) ingredients used as color additives (E171) in foods and beverages contain an appreciable fraction of particles in the nanoscale range. At present, little information is available regarding the potential impact of food-grade TiO₂ nanoparticles on the gastrointestinal fate of co-ingested bioactives, such as nutraceuticals. In this study, the impact of TiO₂ on the bioaccessibility of β-carotene solubilized in model food emulsions was investigated using a simulated gastrointestinal tract model. Raman spectroscopy showed that there was no charge transfer between β-carotene and TiO₂ but that some β-carotene absorbed to the surface of TiO₂ particles. The initial particle size of the food emulsion did not significantly affect β-carotene bioaccessibility, probably because the same amount of free fatty acids (FFAs) was released by the end of digestion. The addition of TiO₂ at levels typically found in foods also had no significant impact on β-carotene bioaccessibility and FFA release, which suggested that this type of inorganic particle does not interfere with the gastrointestinal fate of these lipophilic bioactive agents. This information is important for ensuring the safety of inorganic nanoparticle utilization within the food industry.