A rheological characterisation of mashed potatoes enriched with soy protein isolate

► A mashed potato serving (200 g) with SPI (15-60 g kg−1) provide 3-12 g of protein. ► A mechanistic understanding of SPI-based mashed potatoes systems has been derived. ► The amylose/amylopectin matrix was weakened by SPI aggregates at SPI ⩾ 15 g kg−1. ► There was no interaction between the potato gel matrix and dispersed SPI particles. ► 30 g kg−1 was close to the phase separation threshold in SPI-mashed potatoes samples.