Effects of SOA and saccharin adulteration on Polycose preference in rats

Female rats were tested for their preference for a 32% Polycose solution, and for 32% Polycose solutions made bitter or sweet by adulteration with either 0.05% sucrose octa acetate (SOA) or 0.2% saccharin during 24 hr/day two-bottle tests. The rats preferred the saccharin-Polycose to the Polycose, the Polycose to the SOA-Polycose, and strongly preferred the saccharin-Polycose to the SOA-Polycose solution. Additional rats that were given only a Polycose or an SOA-polycose solution, in addition to chow and water, consumed similar amounts of solution, and consumed as much as did the rats given the saccharin-Polycose solution. Thus, while SOA adulteration reduces, and saccharin adulteration increases, the relative palatability of Polycose, they do not alter the animal's intake when only one solution is available. In a second experiment rats were given the choice between a 32% Polycose solution and pure Polycose powder, between an SOA-Polycose solution and Polycose powder, or between an SOA-Polycose solution and sucrose powder during both 30-min/day and 24-hr/day preference tests. During the initial short-term test the rats preferred the Polycose solution and, to a lesser degree, the SOA-Polycose solution to the Polycose powder, but they strongly preferred the sucrose powder to the SOA-Polycose solution. During the subsequent long-term test, however, the rats developed a preference for the SOA-Polycose solution over the sucrose powder. The mechanism responsible for this preference switch is not certain, but it may be related to the postingestive effects of the solution, and may also be responsible for the rat's hyperphagic response to carbohydrates in solution form but not in powder form.