Revealing the Impact of Starch–Pectin Interactions on the Textural Properties of Different Potato Varieties During Boiling

This study aimed to investigate the changes in textural properties of two potato varieties (JZ-226 and XS-6) during boiling and to elucidate the interaction mechanisms within their starch–pectin composite systems, and their impacts on textural characteristics. The results showed that during the boiling process, both potato varieties exhibited decreased hardness and chewiness. As the boiling time lengthened, starch underwent gelatinization; the amylose content dropped; water solubility increased; and the swelling power, transparency, and iodine blue value reduced. Meanwhile, pectin degraded, with the degree of esterification increasing; the content of protopectin and other bound pectins decreased; and water-soluble pectin increased, along with molecular weight rising. In the early stages of gelatinization (15 min), the addition of pectin inhibited the short-range orderliness of starch, forming a relatively stable network structure. However, prolonged gelation disrupts the gel network structure of the starch–pectin complex, leading to further textural changes. Compared to XS-6, the pectin in JZ-226 demonstrated a stronger ability to inhibit starch short-range orderliness, forming a more stable network structure, thereby maintaining superior hardness. These findings provide a theoretical basis for understanding the molecular mechanisms underlying textural changes in potato processing and offer technical support for developing functional potato products.