Enzymatic Modification of Potato Starch: Starch-Acting Enzyme Resources, Structure–Function Relationships and Value-Added Applications

Potato (Solanum tuberosum L.) starch is valued for its large granules, high paste viscosity, and neutral taste, yet its gelatinized form is rapidly digested and its native granules resist enzymatic attack. This review synthesizes peer-reviewed studies indexed in Scopus, Web of Science, PubMed, Crossref, and Google Scholar from January 2000 to September 2026, with emphasis on 2018 onward, classifying evidence as direct (potato starch as substrate) or extrapolated (other starch systems). Hydrolases depolymerize potato starch, generate porous granules, or supply linear chains for type 3 resistant starch, whereas 4-α-glucanotransferases, branching enzymes, amylosucrase, and cyclodextrin glucanotransferases deplete amylose, elongate exterior chains, introduce α-1,6 linkages, or produce cyclic glucans. The strongest direct evidence supports thermoreversible gels, pullulanase-assisted resistant starch, slowly digestible starch, low-digestibility starch, cyclodextrin production, and acid-assisted porous starch. Ultrasound, high hydrostatic pressure, irradiation, and hydrothermal treatments modulate enzyme accessibility but remain strongly condition-dependent. Translation is constrained by gelatinization and drying energy, reaction viscosity, enzyme cost and recovery, and heterogeneous digestibility assays. Priority actions include raw-granule-active enzymes, standardized potato-starch assays, rational enzyme cascades, structure-guided enzyme engineering, and product-specific human and life-cycle assessments.