Chitin nanocrystals reduce lipid digestion and β-carotene bioaccessibility: An in-vitro INFOGEST gastrointestinal study

Abstract

Engineered nanoscale materials (ENMs) are being intentionally added to some food and beverage products to achieve novel or improved functional attributes. However, there is still a relatively poor understanding of the behavior of many types of ENMs within the human gastrointestinal tract (GIT). In this study, the impact of chitin nanocrystals on the gastrointestinal fate of a model emulsion was investigated using a standardized in vitro digestion model (INFOGEST), which is now widely used by food and nutrition scientists. The results obtained with the INFOGEST model were compared to those obtained with another commonly used static in vitro digestion model. Moreover, the impact of nanochitin dose on the digestibility and bioaccessibility of model food emulsions was examined: β-carotene-loaded corn oil-in-water emulsions stabilized by a non-ionic surfactant (Tween 80). In agreement with the results obtained using an earlier in vitro digestion model, we found that the presence of nanochitin reduced lipid digestion and β-carotene bioaccessibility. However, the magnitude of these effects was considerably less for the INFOGEST model, which was attributed to the higher levels of pancreatic lipases and lower levels of calcium ions used. Overall, this study shows that nanochitin may be used to retard lipid digestion (which is useful for creating foods that induce satiety), but that it also suppresses carotenoid bioaccessibility (reducing the nutritional value of foods). Consequently, food formulators must carefully consider all the potential impacts of edible nanoparticles when using them as functional ingredients in foods.