Evaluation of the texture and the freezing and melting properties for vanilla ice cream of varied fat content

Abstract

Modified starch was used as a fat replacer in light, low fat and fat free vanilla ice creams. The texture of ice creams were compared by trained panelists against regular fat ice cream. Samples having the same targeted composition prepared during separate process trials were observed during preparation to be different. From trial 1, all samples were determined to be similar for the attributes of coldness and firmness with differences found for viscosity, smoothness and mouth coating. From trial 2, all samples were similar for coldness and viscosity although differences were determined between samples for firmness, smoothness and mouth coating. Strong relationships $\rm (R\sp2 > 0.87)$ resulted between the attributes of smoothness and firmness and the level of fat in ice cream. Instrumental measurements showed the light ice cream of both trials to be the highest in viscosity and consistency whereas fat free ice creams showed the highest values for flow behavior. Only in trial 1 did the sensory results for viscosity, smoot ness and mouth coating, relate strongly $\rm (R\sp2 > 0.90)$ to instrumental measurements for flow behavior and firmness. The regular fat ice cream mixes demonstrated the highest average steady-state continuous freezing temperature (${-}4.52\sp\circ$C) whereas all other samples showed similar temperatures. Differences in continuous freezing flow rates were noticed between all samples with fat free ice creams showing the slowest rates of 79.7 and 80.0 kg/hour for trials 1 and 2 respectively. Results from the analysis of ice cream hardening and melting were observed to be highly affected by the type of package and experimental conditions. Based on both sensory and instrumental results, it is clear that the presence of modified starch in light ice cream can mimic many of the properties of regular fat ice cream in terms of texture and freezing properties.