Influence of saccharide length on polysaccharide appetite in the rat

The appetite of female rats for saccharides of different chain lengths was assessed in brief (5-min) one-bottle acceptance and two-bottle preference tests. The saccharides (and their lengths in glucose units) included glucose (1), maltose (2), maltotriose (3), maltooligosaccharide (4-8), maltopolysaccharide (average length 43), and Polycose (1 to 30+); 0.0125 and 0.025 molar solutions of these saccharides were tested. The results revealed that the rats' order of preference for these saccharides was as follows: maltooligosaccharide greater than maltotriose = maltose greater than glucose; and maltooligosaccharide greater than Polycose = maltopolysaccharide greater than maltose. Thus, as saccharide chain length increased from 1 to 4-8 glucose units palatability increased, but with further increases in chain length palatability declined somewhat. Previous findings have suggested that rats have a "polysaccharide" taste receptor and the present results indicate that the receptor is maximally (or near-maximally) stimulated by saccharides of 4-8 glucose units in length.