Influence of the used starch on the structure, stability and rheological properties of a starch-milk dessert cream

Abstract

The stability and rheological properties of starchy dairy dessert creams thickened with corn, potato, wheat, rice, and tapioca starches were compared. A difference in structure was also reported in microscopic imaging. The stability of the creams was assessed by analysing the amount of liquid separated by centrifugation of the samples. Potato starch cream was found to have the least stability after 24, 120, and 240 hours of storage. Wheat starch shows the lowest retrograde properties. Rheological studies were performed at 50 °C in a controlled shear rate mode. The data show that all systems studied are non-Newtonian fluids. The resulting flow curves were analysed using the Herschel-Bulkley model. All creams are pseudoplastic, thinning liquids with time-varying properties. The consistency of creams thickened with rice and wheat starch is significantly more stable than those thickened with corn, potato, and tapioca starch, which was also confirmed by the calculated thixotropic areas.

Physicochemical and Rheological Characteristics of Fermented Sour Cream (“Suero Costeño”) Produced in Colombia

“…As the shear rate increases, randomly positioned chains of polymer molecules align in the direction of the flow, resulting in less interaction between adjacent polymer chains [30]. Similar results were found in creams with different fermentation levels [3], starch-milk dessert cream [27], low and high fat cream [26], recombined cream [13], sour creams supplemented with milk protein concentrate [5], and whipping cream [31]. In general, dairy cream has shear-thinning behavior (pseudoplastic fluid) due to partially aggregated fat globules, which can be broken down at high shear rates [32].…”

“…These high percentages of thixotropy may be due to the addition of some thickeners or stabilizers [25]. This behavior has been reported for dairy cream with some natural stabilizers [26,27], ice cream [28], and yogurt [29]. Furthermore, for the "sueros costeños" that present time dependence, the ascending curve is greater than the descending curve, so they show a positive thixotropy, where the viscosity decreases with time due to a change of the internal structure when a strain is applied.…”

“…The consistency coefficient (K) presented values between 1.64 and 48.58 Pa s n , similar values have been reported for sour creams with different levels of milk protein concentrate (17.6 -26.5 Pa s n ) [5], creams with different fermentation times: 9 h (20.0 Pa s n ) and 12 h (41.96 Pa s n ) [3], but lower than those obtained for creams with the addition of corn starch (173.64 Pa s n ), potato starch (84.05 Pa s n ), and tapioca starch (161.13 Pa s n ) [27]. In general terms, the "suero costeño" that presented the highest consistency coefficient were those made by producers from the municipality of Cereté (Córdoba-Colombia) with average values of 25 and 20 for Kasc and Kdes, respectively.…”