Influence of milk fatty acid composition and process parameters on the quality of ice cream

Abstract

There has been considerable interest in recent years in altering the fatty acid composition of milk fat in dairy products to improve the long-term health of consumers. The objective of this study was to investigate the influence of altering the fatty acid composition and varying two process parameters (homogenization pressure and ageing temperature) on the quality of ice cream. The quality of ice cream (8% fat) was monitored before and after heat shock by assessing fat droplet size, solvent extractable fat content, texture analysis, meltdown tests and sensory analyses. The results suggest that a high solid fat content and low homogenization pressure correlated well with large particles and high amounts of solvent extractable fat, which resulted in firm ice cream with slow melting behaviour and good structure retention. In contrast, ageing temperature did not significantly influence fat destabilization. Following heat shock, the results suggested that the hardness of ice cream was not determined by any of the parameters investigated, but was probably dominated by the amount of ice crystals. A good melting behaviour was retained after heat shock, provided that a strong matrix of destabilized fat was produced during the freezing process. Even though differences could be observed in hardness and melting behaviour for different milk fats or process conditions, these differences were hardly identified by trained sensory panels. These results suggest that high-quality ice cream can be produced with an altered fatty acid composition without any alteration in the conventional production process, provided that ice cream is stored and consumed under ideal circumstances.