It has been proposed that the ability of carbohydrate-based fat replacers to effectively mimic the physical properties of milk fat will be determined by the colloidal properties of the carbohydrates involved and their impact on mouth feel (Specter & Setser, 1994). It is possible that the melting of ice cream within the oral cavity may be influenced by the hydrated particles of the fat replacer such that the perception of creaminess is intensified. Of interest were the relationships noted between smoothness and the instrumental measurement for firmness (plunger) and tackiness (knife; Table 6), which suggests the firmness of the sample may influence the perception of smoothness.
The results for smoothness (Table 3) indicate that a decrease in ice cream smoothness occurs when the fat level is decreased from light (5.20%) to low fat (2.40%) or fat free (0.50%). The contribution of fat content to ice cream smoothness is also apparent in the strong correlation between smoothness and fat content (Table 4). This relationship is in agreement with previously published results where decreases in creaminess were reported when the fat level was decreased from 10 to 3% (Morris, 1992) and from 12 to 8% or from 8 to 3% (Stampanoni Koeferli et al., 1996). It would appear, therefore, that the use of modified starches in ice cream with less that 5% milk fat does not result in products with smoothness or creaminess similar to that of the regular fat ice cream.