Crystallization Behavior of High-Oleic High-Stearic Sunflower Oil Stearins Under Dynamic and Static Conditions

Abstract

Soft (SS) and hard (HS) stearins obtained from high-oleic high-stearic sunflower oil were isothermally crystallized under dynamic (with agitation) and static conditions at 16, 17, 18, 19, and 20 °C and 24, 25, 26, 27, and 28 °C, respectively. Both fractions crystallized under the α-form at early stages of crystallization for all temperatures (T c) tested. Polymorphic behavior strongly changed with T c and shear conditions for both fractions. SS fractions were characterized by α, β2 and/or β1 polymorphs at lower T c and β1 crystals at higher T c when crystallized under dynamic conditions, while this same fat system was characterized by β2′ crystals at lower T c and β2 at higher T c under static conditions. HS samples were mainly characterized by α and β2 crystals at lower T c and α and β1 crystals at higher T c when crystallized under dynamic conditions; while the same fat was characterized by β1′ crystals when crystallized at lower T c and α when crystallized at higher T c under static conditions after 90 min at T c. These different polymorphic behaviors, in combination with the different processing and tempering temperatures are translated in specific textural behavior of the samples.