Influence of Hydrocolloids and Sweeteners on Flow Behaviour of Peach Nectar

Influence of adding six hydrocolloids, guar gum, carrageenan, carboxymethylcellulose and three types of pectin, and of sweeteners, aspartame and fructose, as replacement of sucrose, on flow behaviour of peach nectar was studied. A series of peach nectar samples (with approximately 65% fruit) was prepared using commercially processed peach purée with sucrose and substituting sugar with low-calorie sweetener aspartame and fructose (alone and in combination in a sweetness ratio of 1:1) taking into account their sweetness. To prevent reduction of viscosity and mouthfeel/body of low-calorie peach nectars, different concentrations of hydrocolloids were added. A control sample was prepared by mixing fruit purée with a sucrose solution (7% mass fraction) to provide 14% (in total solids) nectar. Rheological measurements were carried out on a rotational viscosimeter Rheotest 3 at 20 °C and 5 °C. The flow of all peach nectars was characterized as pseudoplastic. Among all used hydrocolloids, addition of only 0.03% of carrageenan to the peach nectar was enough to obtain viscosity similar to the viscosity of the control sample.