High pressure crystallization of binary fat blend: A feasibility study

Abstract

Crystallization mechanism of triglycerides plays an important role in structuring of the plastic fats, such as margarine and shortening. The effects of cooling under high pressure on crystallization and functional properties of a mixture of fully hydrogenated soybean oil and soybean oil (3:7 mass ratio) at 30 °C were investigated and compared against samples crystallized under atmospheric condition. Experiments were conducted using a face-centered central composite design. It is shown that pressure level, initial temperature, and maximum temperature under pressure affect sample's storage modulus, yield stress and percent oil loss. Holding time and pressure pulsing did not significantly influence the properties. Inverse relationships between the mechanical properties and percent oil loss were observed. Presence of crystal seeds in the sample prior to pressurization yielded lipid crystals with different polymorphic properties than those directly crystallized from the melt. The study demonstrates that high pressure processing can improve plasticity and physical properties of fat blends with low saturated fat content. High pressure crystallization is proven to offer better crystallization properties with lower supercooling condition and prevent the need for long hour incubation.