Preferred Characteristics of Starch Powder for Producing Starch Pearls by Disc Granulation

Nine representative starches (amylose content 1.9%-67.1%) from cereals, tubers, and legumes are selected as raw powders to produce starch pearls by disc granulation. All starch powders could be granulated into starch pearls, but the starch pearls made from waxy and high-amylose corn starch are unable to withstand cooking. Cluster and Pearson correlation analysis further indicates that to produce starch pearls with high granule strength and good cooking and texture qualities, the selected starch preferably has the following characteristics: 1) a lower amylose content (ranging from 25.9%-41.6% in this study); 2) a lower pasting temperature; 3) a higher ratio of amylopectin extra-long chains (DP & GE; 36) to amylopectin short chains (DP 6-12); 4) a larger particle size. Among the nine starches, potato and cassava starches are the most suitable for producing starch pearls by disc granulation. In addition, it is suggestive that Rapid Visco Analyzer analysis of starch powder can be used to rapidly predict the critical cooking and texture qualities of starch pearls, including transparency, hardness, and chewiness. This study not only provides an economical method to produce starch pearls, but also establishes a preliminary theory for selecting starch raw materials.