Relationships between ice cream mix viscoelasticity and ice crystal growth in ice cream

The relationship between ice cream mix viscoelasticity and ice crystal growth in ice cream as a function of stabilizer addition was studied by a simulation of freeze-concentration using a series of ice cream mixes containing reduced quantities of water. Ice cream mixes were formulated with guar gum concentrations ranging from 0 to 0.25% and a series of concentrated mixes from each initial formulation was prepared for viscoelastic measurements by successively decreasing the water content. By plotting apparent viscosity or storage modulus against concentration factor based on Rater removed, a change in slope (breakpoint) could be seen. Ice crystal size analysis in ice cream before and after heat shock testing showed a minimum in recrystallization rate when the concentration of guar gum was 0.14% in the mix. At lower or higher concentrations the recrystallization rate was higher. Normalized breakpoint viscosity correlated well with recrystallization rate. Thus, it appears that stabilizer contributes to recrystallization protection in ice due to a change in polysaccharide behaviour that results from freeze-concentration. (C) 2001 Elsevier Science Ltd. All rights reserved.