Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study

This paper provides guidance on the conduct of new in vivo and in vitro studies on high molecular weight food additives, with carrageenan, the widely used food additive, as a case study. It is important to understand the physical/chemical properties and to verify the identity/purity, molecular weight and homogeneity/stability of the additive in the vehicle for oral delivery. The strong binding of CGN to protein in rodent chow or infant formula results in no gastrointestinal tract exposure to free CGN. It is recommended that doses of high Mw non-caloric, non-nutritive additives not exceed 5% by weight of total solid diet to avoid potential nutritional effects. Addition of some high Mw additives at high concentrations to liquid nutritional supplements increases viscosity and may affect palatability, caloric intake and body weight gain. In in vitro studies, the use of well-characterized, relevant cell types and the appropriate composition of the culture media are necessary for proper conduct and interpretation. CGN is bound to media protein and not freely accessible to cells in vitro. Interpretation of new studies on food additives should consider the interaction of food additives with the vehicle components and the appropriateness of the animal or cell model and dose–response. •Include analyses of additive identity, purity and its homogeneity/stability in vehicles.•Consider effects of additive on vehicle palatability and viscosity.•Some high Mw additives should be dosed at ≤5% of diet to avoid nutritional deficiency.•Understand the binding of additives to protein in vehicles.•Consider the stability, properties and relevance of the cell type in in vitro tests.