Energy utilization of sorbose in comparison with maltitol in growing rats

Energy utilization of L-sorbose was investigated in two experiments. In experiment 1, growing rats were fed a control diet containing cornstarch as a carbohydrate or glucose, sucrose, sorbose, and maltitol for 6 weeks at 10% level. Dietary sorbose appeared to be an inefficient source of energy compared with other dietary carbohydrate sources except for maltitol, because there were significant decreases in values for body weight gain, food efficiency, body lipid accumulated, and total energy accumulated. In experiment 2, [U-¹⁴C]sorbose was administered (200 mg/kg of body weight) to sorbose-adapted and -unadapted rats, and [U-¹⁴C]maltitol was administered to maltitol-adapted rats. Both adaptation levels were 900-1000 mg/kg of body weight and were done for 1 week. The recovery of radioactivity of expired CO₂ in sorbose-adapted rats was significantly lower and 60% of that in maltitol-adapted counterparts. Both urinary and fecal excretions of radioactivity were significantly increased in [U-¹⁴C] sorboseadministered rats compared to in [U-¹⁴C]maltitol-administered animals. Fecal recovery of radioactivity in sorbose-adapted rats was less than in sorbose-unadapted rats.