Taste difference thresholds for monosodium glutamate and sodium chloride in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi)

Abstract

The purpose of this study was to determine taste difference thresholds for monosodium glutamate (MSG) and sodium chloride (NaCl) in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi). Using a two-bottle preference test of brief duration, three animals of each species were presented with four different reference concentrations of 50, 100, 200, and 400 mM of a tastant and tested for their ability to discriminate these from lower concentrations of the same tastant. The just noticeable differences (JNDs), expressed as Weber ratios (DeltaI/I), were found to range from 0.1 to 0.5 for MSG and 0.2 to 0.45 for NaCl in the pigtail macaques, with a significant tendency for higher Weber ratios with higher reference concentrations. In the spider monkeys, JNDs ranged from 0.15 to 0.4 for MSG and 0.1 to 0.25 for NaCl, with Weber ratios staying fairly constant across the reference concentrations tested. Thus, the JNDs were found to be generally similar in both species and to be at least as low as those found in humans for MSG and NaCl, as well as those found in spider monkeys for sucrose. The results support the assumption that both pigtail macaques and spider monkeys may use differences in perceived intensity of MSG and NaCl as a criterion for food selection.

Gustatory Responsiveness to Six Bitter Tastants in Three Species of Nonhuman Primates

“…This rather conservative criterion was chosen for reasons of comparability of data, as the same criterion had been used in previous studies that used the same method with the same primate species (Laska 1994(Laska , 1996(Laska , 1997(Laska , 1999(Laska , 2000Laska et al 1996Laska et al , 1998Laska et al , 1999Laska et al , 2000aLaska et al , b, 2001Laska et al , 2008Laska and Hernandez Salazar 2004), and in order to avoid misinterpretation of data due to a too liberal criterion.…”

Taste preferences and feeding behaviour in the facultative herbivorous fish, Nile tilapia Oreochromis niloticus

“…Nonetheless, differences in dietary habits plausibly explain differences of some mammals in their taste performance, mainly in gustatory sensitivity to the particular compounds presented in food (Spector, 2000). In nonhuman primates, e.g., the degree of frugivory has been found to be positively correlated with sensitivity to some food-associated compounds (Laska et al, 2008(Laska et al, , 2009. A comparison of 30 mammal species revealed a relationship between sensitivity to quinine hydrochloride and dietary specialization, with carnivores > omnivores > grazers > browsers (Glendinning 1994).…”