Viscoelastic properties of four vegetable-based infant purees were evaluated in temperature range of 5–80C. Samples behaved like weak gels, with the exception of rice and chicken puree at 35, 50 and 65C, which behaved like a macromolecular solution. At 5–65C, storage modulus (G′) and storage loss (G″) could be well described by a power function of the frequency (R2 > 0.92), and the dependency of their parameters with temperature was modeled by Arrhenius's model and quadratic functions. Approach named “weak gel model” was also applied to the baby foods, and both G′ and G″ values decreased with an increase in temperature between 5 and 50C. Master curves were obtained applying time-temperature superposition principle, and horizontal shift factor was sensitive to choice of viscoelastic property being selected for shifting procedure. At 5–50C, infant purees behaved like thermoreologically complex materials. Rheological measurements were well supported by particle size distributions.
Composition of baby foods is being continually modified and adapted with the aim of producing healthier foods. However, there are no recent rheological studies of vegetable and fruit puree-based baby foods. A comprehensive study on viscoelastic behavior of four current commercial types of Spanish vegetable-based infant purees was carried out. The effect of a wide range of temperatures, which are encountered during processing and storage of baby foods, on rheological properties was documented. Based on frequency sweep data, the dynamic rheological behavior of these products ranged from that of a concentrated biopolymer solution to a “weak gel.” Controlling temperature, moisture content and particle size distribution may be employed to optimize applicability, stability and sensory of baby foods. Results provide a useful fingerprint of rheological behavior of these products. Generated data and findings can be extrapolated to other infant systems for developing new products for convenience to newborn consumers and manufacturers.