Starch blends and their physicochemical properties

In this paper, the current knowledge on properties of starch blends is critically reviewed. Nowadays, chemical modifications are commonly applied to modify starch properties. However, industry calls for alternatives for chemically modified starches to address the consumer's demand for natural food systems. A simple way to impact starch properties is by blending different starches. In some blends, interactions lead to unexpected gelatinization, pasting, gel texture, and retrogradation properties (non-additive effect), while an additive effect occurs when the behavior of the blend corresponds to what can be expected based on the individual components. Analysis of different studies describing the physicochemical properties of blends brings insight into the role of botanical origin, amylose content, starch-to-water ratio, ratio of starches in the blend, etc. in the behavior of the blends. Gelatinization occurs mostly independently in excess water, while at intermediate water content more non-additive behavior is recorded. Pasting, rheological, and textural properties show primarily non-additive effects while retrogradation of starch blends occurs mainly in an additive way. Large differences in granule size and swelling power between the starches in a blend lead to uneven moisture distribution during heating of the starch suspension, which results in a different behavior of the blend than what would be expected based on the behavior of the individual starches.