Structure and physicochemical properties of starch affected by dynamic pressure treatments: A review

Background Starch is an important ingredient in many applications, while there is increasing interest to modify starch functionalities using physical means. Dynamic pressure treatments are emerging techniques for food processing and food safety applications. The treatments have potential in modification of functional properties of food ingredients including starch. Scope and approach This review summarizes the effects of 3 types of dynamic pressure treatments on structure and physicochemical properties of starches from different plants. The 3 treatment methods include high pressure homogenization, high pressure microfluidization and high speed jet processing. Starch and process related parameters affecting the modification outcomes are analyzed. Starch related applications affected by the dynamic pressure treatments are described. Structure-function relationships of starch components affected by the treatments are critically discussed. The effects of dynamic pressure treatments on starch properties and applications are compared with those of other physical techniques including high hydrostatic pressure processing. Research directions to expand the applications of dynamic pressure treatments on starch modifications are suggested. Key findings and conclusions Dynamic pressure treatments tend to degrade starch on the granular and molecular level, while facilitating physicochemical interactions of starch via process intensification. The treatments induce starch gelatinization and increase starch digestibility, while affecting rheological properties in a treatment type- and condition-dependent manner. Increasing pressure level and number of passes leads to more drastic changes in starch properties. The treatments can facilitate starch modification processes such as formation of starch-guest molecule inclusion complexes, nanoparticle production and starch esterification. Overall, dynamic pressure treatments have potential to expand the range of starch functionalities for different applications.