Heat-induced changes in microstructure of spray-dried plant protein isolates and its implications on in vitro gastric digestion

Andrea Rivera del Rio*, Mauricio Opazo-Navarrete, Yamira Cepero-Betancourt, Gipsy Tabilo-Munizaga, Remko M. Boom, Anja E.M. Janssen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)


The quickly expanding field of plant-based food, generally uses protein concentrates or isolates as protein source. It is however not clear to what extent the intensive processing of these raw materials affects their digestibility. We here report on the in vitro gastric digestibility of the structures present in unheated and heated dispersions of spray-dried protein isolates of soybean and yellow pea. Unheated dispersions consist primarily of insoluble individual spray-dried particles, agglomerates of these and only a small fraction of soluble protein. Pepsin activity was followed in real-time through microscopic observations, showing the disassociation of agglomerates and inward-breakdown of individual particles, which are otherwise stable at gastric pH and ionic strength. This demonstrates that solubility is not necessarily an incentive for gastric protein digestion. Heating does not significantly affect the overall digestibility of protein isolate dispersions. Nevertheless, heating disrupts the structure of spray-dried particles, increasing the amount of smaller and better digestible particles that remain suspended after centrifugation. Conversely, heat-induced aggregates remain in the pellet and are up to 50% less digestible than their unheated counterparts. This impaired digestibility is counterbalanced by a reduced proportion of poorly-digestible species in the full system (up to 11% for soy and 23% for pea).

Original languageEnglish
Article number108795
Publication statusPublished - Jan 2020


  • Gastric digestion
  • In vitro digestion
  • Pea protein isolate
  • Protein digestibility
  • Soy protein isolate
  • Spray-dried protein isolates

Fingerprint Dive into the research topics of 'Heat-induced changes in microstructure of spray-dried plant protein isolates and its implications on in vitro gastric digestion'. Together they form a unique fingerprint.

Cite this