Saccharin preparations commonly distributed as artificial sweeteners exhibited mutagenic activity in bacterial tests. When administered orally to mice, mutagenic activity was demonstrable in the urines of these animals as well as in a host-mediated assay. Highly purified saccharin was not mutagenic in the direct assay, but the urines of mice to which this material had been administered exhibited mutagenic effects on one tester strain (Salmonella typhimurium TA100). Two other sweeteners, neohesperidin dihydrochalcone and xylitol, had no detectable mutagenic activity in any of these assays using his- Salmonella typhimurium strains TA100 or TA98.

The nutritional value of corn tortillas was substantially improved when supplemented with cottonseed flour (CSF) as noted by ammo acid analysis and rat growth studies. This is probably attributable to improved contents of lysine and tryptophan. The leucine-isoleucine ratio also was improved. Rats showed the greatest weight gain from tortillas supplemented with 20 and 25% CSF. Protein efficiency ratio and net protein ratio values of the latter were not significantly different than those of casein. Tortillas supplemented with CSF showed an improved shelf life as noted by lower fat acidity values. There were no significant differences in acceptability of the supplemented tortillas.