Taste responses to neohesperidin dihydrochalcone in rats and baboon monkeys

Abstract

Preference-aversion behavior to solutions containing neohesperidin dihydrochalcone (NHDHC) was studied rats and baboon monkeys. Electrophysiological responses evoked by application of NHDHC solutions to taste receptors innervated by the chorda tympani and the glossopharyngeal nerves were also measured. As a group, rats were indifferent to solutions containing up to 1.2×10⁻³ M NHDHC in short and long-term preference tests. A solution containing the very high concentration of 8.2×10⁻³ M NHDHC was consumed less than water by all rats. The aversive behavior of rats to the 8.2×10⁻³ M NHDHC solution appeared to be due to taste quality rather than olfaction. When percent preferences were calculated on an individual basis for the long-term preference tests, 59% of the rats were indifferent to solutions containing up to 1.2×10⁻³ M NHDHC, 33% of the animals found this solution aversive and less than 8% showed preference. Behavioral responses to a solution of 3.4×10⁻⁴ M aspartame also varied considerably among rats. The electrophysiological data were in line with the behavioral responses suggesting weak taste responses for NHDHC in rats. More pronounced responses observed in the glossopharyngeal nerve as compared to the chorda tympani. Baboon monkeys showed a strong preference for solutions containing 1.6×10⁻⁵ M–1.6×10⁻³ M NHDHC. A solution of 1.6×10⁻² M was consumed to a lesser extent than water. It is concluded that baboon monkeys present a better experimental model than rats for investigating the sweetness of NHDHC.