Are cellulose nanocrystals “alien particles” to human experience?

Abstract

A wide family of cellulose‐based additives are authorized worldwide as fillers and thickening agents in foods, pills, and tablets, and microcrystalline cellulose (MCC) is, among these, the most important one. Since MCC manufacturing is similar to the main production route of cellulose nanocrystals (CNCs), it is reasonable to wonder whether the MCC would contain CNCs as minor components. In this Short Communication, we provide first results about the occurrence of CNCs in MCC, observed by dynamic light scattering and transmission electron microscopy after serial filtrations of MCC suspensions. The incidence of cellulose nanoparticles has been proved in several different trials in our ongoing works on diverse MCC samples, and the nanoparticles isolated showed shape and dimensions similar to those commonly produced by acidic hydrolysis at laboratory level. Therefore, the presence of CNCs in many products is considered as a certainty. The foods and the pharmaceuticals we have been consuming so far do indeed contain traces of CNCs to such an extent that this wide presence in consumed products should be taken into account when considering possible limitations of the use of these nanoparticles in food contact materials manufacture.

Manufacturing of Food Packaging Based on Nanocellulose: Current Advances and Challenges

“…A recent work demonstrated that cellulose nanoparticles have always been part of our daily intake. The findings provided further necessary and preliminary information/data to the EFSA for the approval of the cellulose nanoparticles as FCMs [116]. Although studies have shown that, for 10 nm diameter particles, an apparent diffusion coefficient (D) of 1.1 × 10 −35 cm 2 s −1 theoretically calculated in a LDPE host matrix exhibits a benign risk of inadvertent migration [117], it remains that the same investigation has to be performed specifically on CNCs to confirm those results.…”

Pilot plant scale-up of the production of optimized starch-based biocomposites loaded with cellulosic nanocrystals from Posidonia oceanica waste biomass

“…It should be noted that the approval of cellulose nanocrystals to be used as food contact materials (FCMs) is still under evaluation in Europe, although recent studies are being taken into account by the EFSA for their positive assessment (Fotie, Limbo, & Piergiovanni, 2020;Piergiovanni, Fotie, Amoroso, Akgun, & Limbo, 2019). However, other countries like Canada have recently unrestricted the commercialization and use of cellulose nanocrystals, according to their lack of toxicity as observed by several regulatory protocols.…”

Toxicological Assessment of Cellulose Nanomaterials: Oral Exposure

“…The majority of applications of CNMs in food technology or biomedical applications are still in the early R&D stages, but they are expected to reach the market in the near future. Nevertheless, as recently suggested, CNMs-and particularly CNCs-might already be present in many food products and pharmaceuticals [118]. Studies have suggested that CNCs may represent a small fraction of the particles present, for example, in microcrystalline cellulose (MCC)-a typical food and drug additive that is considered to be safe.…”

“…Studies have suggested that CNCs may represent a small fraction of the particles present, for example, in microcrystalline cellulose (MCC)-a typical food and drug additive that is considered to be safe. This observation was based on a preliminary study, in which particles with diameter/width less than 100 nm were found after serial filtration of MCC suspensions [118]. However, the presence of CNMs in food/food packaging products or pharmaceutical/nutraceutical drugs is currently largely unknown.…”