The fate of cellulose nanocrystal stabilised emulsions after simulated gastrointestinal digestion and exposure to intestinal mucosa

Research finds that CNCs as insoluble fibre, may have benefits in terms of differential lipid absorption (slowing absorption of saturated fat).

It is well recognised that the average UK diet does not contain sufficient fibre. However, the introduction of fibre is often at the detriment of the organoleptic properties of a food. In this study on the gastrointestinal fate of nanoparticles, we have used cellulose nano-crystals (CNCs) as Pickering stabilising agents in oil in water emulsions. These emulsions were found to be highly stable against coalescence. The CNC and control emulsions were then exposed to simulated upper gastrointestinal tract digestion and the results compared to those obtained from a conventional protein stabilised emulsion. Finally the digested emulsions were exposed to murine intestinal mucosa and lipid and bile absorption was monitored. Importantly, the results show that the CNCs were entrapped in the intestinal mucus layer and failed to reach the underlying epithelium. This entrapment may also have led to the reduced absorption of saturated lipids from the CNC stabilised emulsion versus the control emulsion. The results show the potential of CNCs as a safe and effective emulsifier.

The reasearchers, lead by Professor Alan Mackie, used very small particles made from the insoluble dietary fibre (cellulose nano-crystals, CNCs) to make a very stable emulsion (similar to milk). They have found that the insoluble fibre became entrapped in the protective lining of the intestine and lowered the absorption of saturated fat compared to a conventional protein stabilized emulsion. The results show the potential of CNCs as a safe and effective emulsifier.

The findings will be of interest to functional food producers and those interested in the valorisation of cellulose waste. There is potential here to add more functional fibre into the diet. However, there is still work to be done to develop ways to scale-up the production of the CNCs.

The work was funded by the BBSRC as part of a core grant to the Institute of Food Research (now Quadram Institute) and the authors now work in Leeds or Kings College London.