Particle size characterization of starch-lipid composites

Starch-lipid composites (SLC) have been used as fat replacers and stabilizers in beef patties, dairy products and baked goods, and the technology has been patented under the trademark Fantesk. The SLC are produced by mixing aqueous starch slurry with a lipid source and by steam jet cooking. The SLC may be dried using a drum drier and then milled in a Retsch mill (Brinkmann Instruments, Inc., Westbury, NY). Particle size distribution of SLC may affect the functional characteristics and textural properties of the end products. In this work, the particle size distribution of three starches and 18 SLC, after they were processed through steam jet cooker, drum dried, and milled, was studied. Particle size distribution was evaluated using geometric mean diameter (GMD), geometric SD, cumulative undersize distribution (d(16) and d(40)), particle size index and particle size distribution coefficient (C-m). Particle size distribution of the dried and milled SLC differed significantly from that of the cooked starches as measured by different particle size characterization parameters. The lipid source (canola or butter) and content (10, 20, 30 g/100 g) did not significantly affect the particle size characterization. The starch type had a significant influence on the particle size characteristics of SLC, with distinct differences between waxy and high-amylose (HA) starches. Waxy SLC tended to have smaller mean particle sizes but with a broad distribution, while HA SLC had bigger GMD and smaller particle size coefficient.