Nutritional and toxicological properties of some raw and modified starches

Several food additives, including some raw and chemically modified starches, sorbitol and maltitol, cause caecal enlargement when fed to rodents. The onset of caecal enlargement is rapid and it is reversible when the additive is withdrawn. This poses problems in the safety evaluation of such additives, both in relation to the significance of the caecal enlargement and to the associated effects on food efficiency and nitrogen balance. The mechanisms of causation of caecal enlargement have been studied and will be discussed with particular reference to resistance of starches to enzymic hydrolysis, changes in intestinal microflora, osmotic load in the caecum, cell hyperplasia and rate of turnover of mucosal cells. Where deaths occur, these appear to be due to secondary effects such as impaired resporatory function.